THE 456th FIGHTER INTERCEPTOR SQUADRON

THE PROTECTORS OF  S. A. C.

 

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Convair B-36 "Peacemaker" Intercontinental Strategic Bomber

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CONVAIR B-36J

B-36J

The B-36, an intercontinental bomber, was designed during WW II. The airplane made its maiden flight on August 8, 1946 and on June 26, 1948 the Strategic Air Command received its first B-36 for operational use. By August 1954, when production ended, more than 380 B-36s had been built for the USAF.

In 1958-59, the B-36 was replaced by the more modern B-52. During the years it was in service, the airplane was one of America's major deterrents to aggression by a potential enemy. The fact that the B-36 was never used in combat was indicative of its value in "keeping the peace."

The Museum's B-36J was flown to Wright Field from Davis-Monthan AFB, Arizona, on April 30, 1959. This was the last flight ever made by a B-36. It was also the first airplane to be placed inside the new Museum building.

Courtesy Of The Air Force Museum

 

 

The XB-36 Prototype

 

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A rare color image of the XB-36 in flight.7th. Bomb Wing photo. XB-36 with B-29 parked close for size comparison.
 
XB-36 in Flight
 

This XB-36 was equipped with the 'runway breaker' wheels which were later replaced with four smaller wheels on each side.

 

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Convair XB-36

The original XB-36 main landing gear.

The redesigned main landing gear

The original main landing gear on the XB-36 consisted of a single very large wheel and tire on each strut. This arrangement created so much pressure on the ground that only three airfields in the entire United States were capable of handling an XB-36 landing. Convair engineers were forced to redesign the main landing gear to spread the weight of the aircraft over a larger ground contact area. The redesigned landing gear consisted of mains with four smaller wheels and tires. This new arrangement was incorporated into all production B-36s and retrofitted to the XB-36 and YB-36. The modifications to the XB-36 were completed in June 1948. The XB-36 remained in service until 1957 and was used primarily for special projects and crew training.

 

 

TYPE
XB-36
 

Number Built/Converted
1
 

Remarks
Very large bomber design
 

SPECIFICATIONS
Span:
230 ft. 0 in.
Length: 163 ft. 0 in.
Height: 46 ft. 10 in.
Weight: 265,000 lbs. (max. gross weight)
Armament: Designed for ten .50-cal. machine guns and five 37mm cannon plus 77,784 lbs of bombs. (No defensive armament was actually installed)
Engines: Six Pratt & Whitney R-4360-41 radials of 3,500 hp. each (takeoff power)
Crew: 15

PERFORMANCE
Maximum speed:
346 mph. at 35,000 ft.
Cruising speed: 216 mph.
Range: 3850 miles with 77,784 lbs. bomb load. (estimated)
Service Ceiling: 38,000 ft.

 

XB-36, 42-13570 Prototype of the Peacemaker.

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To emphasize the size of the prototype XB-36 Peacemaker, it was posed next to the previous superbomber, the Boeing B-29 Superfortress. Convair photo 10-1796.

The XB-36 initially had main wheel tires nine feet in diameter. They were later replaced with four wheel bogies like those on late production Peacemakers.

The XB-36 cockpit was stepped in a conventional fashion. The raised greenhouse canopy was introduced on the YB-36.

 

XB-36 with a C-87 transport version of the Convair Liberator flying chase. Photo courtesy AFFTC/HO.

XB-36 in flight. Convair photo 10-2148.

Color photo of the XB-36 in flight.

Color photo of the XB-36 in flight.

 

 

XB-36 photo from an Air Force photo album.

 

 

The propeller of the XB-36 was 19 feet in diameter. Hot air from the manifold was piped through hollow steel joints for anti-icing.

 

 

A Test Takeoff Of A B-36 Bomber Equipped With Caterpillar-Type Landing Gear

AC-37597

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Main landing gear detail

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XB-36 Prototype

The first takeoff and landing of the Air Force's experimental XB-36 bomber equipped with a caterpillar-type track landing gear was made on March 29, 1950, at the Fort Worth Division of Consolidated Vultee (Convair) Aircraft Corporation. With the track-type gear, the weight of the XB-36 rests on Bogie Wheels rolling on two endless belts on each main landing gear strut. Two smaller endless belts are installed on the nose gear strut. The gear, which is retractable, is the latest step in the Air Force's program of track-type gear development. The track on the main landing gear is designed for a maximum average of 57 pounds pressure per square inch on the landing strip, as compared to a pressure of 156 pounds per square inch exerted by the conventional wheel-type gear on a B-36 at the same gross weight. The Bogie Wheels around which the track travels are made of a new magnesium alloy containing zirconium, giving the wheels an especially high impact resistance. Friction is reduced to a minimum by the use of 185 tapered roller bearings weighing approximately 500 pounds.

Released Washington, D.C. April 12, 1950.

The caterpillar-type landing gear was fitted primarily to gather test data when fitted to a very heavy aircraft. The original main landing gear design with a single large wheel and tire was redesigned in the late 1940s and fitted to all production B-36s and retrofitted to the XB-36 and YB-36. The new landing gear arrangement had a two wheel nose gear and 4 wheel mains.

 

Convair XB-36Photo Archive

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Convair XB-36 with Caterpillar Landing Gear

Preparing for taxi test through a grass field

Main landing gear detail - note the aft portion is sunk into the grass about 18".

Nose landing gear detail

 

Convair XB-36

 

 

 

The YB-36

 

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The YB-36

The Convair YB-36 was the second aircraft put on contract and the only service test model built. The YB-36 featured the raised dome cockpit canopy which would become standard on all production B-36s. Like the XB-36, the YB-36 was initially fitted with the large single wheel main landing gear. The production aircraft 4-wheel main landing gear struts were retrofitted to the aircraft during testing.

The YB-36 was essentially built to B-36A specifications and since its purpose was primarily for testing flight characteristics, no defensive armament was installed. The first flight of the YB-36 was on 4 December 1947 six months after the initial flight of a B-36A (28 August 1947).

TYPE
YB-36
 
Number Built/Converted
1
 
Remarks
Service test pre-production A/C
 

SPECIFICATIONS
Span:
230 ft. 0 in.
Length: 162 ft. 1 in.
Height: 46 ft. 8 in.
Weight: 310,380 lbs. (max. gross weight)
Armament: Designed for ten .50-cal. machine guns and five 37mm cannon plus 72,000 lbs of bombs. (No defensive armament was actually installed)
Engines: Six Pratt & Whitney R-4360--25 radials of 3,000 hp. each (takeoff power)
Crew: 15

PERFORMANCE
Maximum speed:
345 mph. at 32,000 ft.
Cruising speed: 202 mph.
Range: 3,380 miles with 10,000 lbs. bomb load. (estimated combat radius); 9,136 mile ferry range
Service Ceiling: 39,100 ft.

The Air Force Museum

 

The Convair B-36 was the largest bomber, in sheer physical size, that has ever gone into service with the USAF. During the late 1940s and early 1950s, the B-36 was the mainstay of the USAF's long-range strategic bombing deterrent. Serving primarily as a strategic deterrent, the B-36 never saw any combat, although some B-36 reconnaissance aircraft flew some rather hazardous missions near or perhaps even over Soviet territory during the height of the Cold War in the mid-1950s.

The origin of the B-36 can be traced back to the early days of 1941, at a time when it seemed that Britain might fall to a German invasion, depriving the USA of any European allies in case of war, and, in particular, leaving the Army Air Corps without any bases outside the Western Hemisphere. Consequently, the Air Corps felt that it would need a truly intercontinental bomber with unprecedented range, one that could bomb targets in Europe from bases inside the continental USA. In search of such an aircraft, on April 11, 1941, the USAAC, in an atmosphere of high secrecy, opened up a design competition for a bomber with a 450 mph top speed, a 275 mph cruising speed, a service ceiling of 45,000 feet, and a maximum range of 12,000 miles at 25,000 feet. It had to be able to carry a 10,000 pound bombload a distance of 5000 miles away and return, and had to be able to carry 72,000 pounds of bombs over a reduced range. It had to be able to take off and land on a 5000-foot runway. These requirements were far beyond the state of the art at the time.

Invitations for preliminary design studies were sent to the Consolidated Aircraft Corporation and to the Boeing Airplane Company. A month later, Northrop Aircraft, Inc was asked for further design studies on its "flying wing" bomber proposal. On April 19, the Douglas Aircraft Company was given a contract to determine if the Allison V-3420 W-type liquid-cooled engine could be adapted as a bomber powerplant. Much later, the Glenn L. Martin Company was also solicited, but declined the invitation due to a shortage of engineering personnel.

On May 3, 1941, a preliminary proposal was submitted by Consolidated. The company designation for the project was Model 35, although at this time it was still uncertain whether a 6-engine or a 4-engine format would be used. Twin fins and rudders were employed by the Model 35.

In order to accelerate the intercontinental bomber project, a conference of high-ranking USAAF officers met on August 19, 1941 and decided to scale down their requirements. The maximum range requirement was reduced to 10,000 miles and the effective combat radius requirement was cut to 4000 miles with a 10,000 pound bombload. The cruising speed should be somewhere between 240 and 300 mph, and the service ceiling should be 40,000 feet.

On October 3, 1941, a review of preliminary data from Boeing, Consolidated, and Douglas was held. At that time, the Materiel Division of the USAAF decided that the Consolidated study was the most promising. At this stage, the Consolidated proposal still covered several different designs, both 4- and 6-engine pusher and pusher-tractor combinations. On October 16, Major General Henry H. Arnold, Chief of the USAAF directed that the Consolidated proposal should be proceeded with. On November 15, 1941, a contract for two experimental aircraft was issued under the designation XB-36. The contract was designated W535-AC-2232. On November 22, the Engineering Division at Wright Field concluded that the 6-engine design rather than the 4-engine design should be adopted, but the twin fin-and-rudder format was retained. On December 10, Consolidated redesignated the Model 35 the Model 36 so that it would not be confused with the Northrop flying wing, which was then known as the B-35.

The two XB-36s were to be built in San Diego, with the first one to be delivered by May of 1944. At the head of the chain of command at Consolidated was I. M. Laddon, the executive vice president. Key members of the Model 36 team were Harry A. Sutton, head of the Engineering Department, Ted P. Hall, head of the preliminary design group, Ralph L. Bayless, head of the Aerodynamics Group, Ken Ward, in charge of finalizing the external shape, and Robert H. Widmer, in charge of wind tunnel testing. By this time, the wing span had grown to 230 feet with an area of 4772 square feet. The wing had a slight sweepback, and sat high on a circular-section fuselage. The aircraft was to be powered by a set of six 28-cylinder Pratt & Whitney "X" air-cooled radials. This engine was based on a pair 14-cylinder R-1830 Twin Wasp engine connected together, and in 1941 existed only on paper. These six engines were each to drive a 19-foot three-bladed Curtiss propeller in pusher configuration. The engines were to be accessible for maintenance in flight via passageways in the 7.5-foot thick wing root. Six fuel tanks with a capacity of 21,116 US gallons were incorporated into the wing. The 163-foot fuselage had four separate bomb bays with a maximum capacity of 42,000 pounds. Like in the B-29, only the forward crew compartment and the gunner's weapons sighting station compartment behind the bomb bay were to be pressurized. A 25-inch diameter, 80-foot long pressurized tube ran alongside the bomb bays to connect the forward crew compartment to the rear gunners' compartment. Crewmen could use a wheeled trolley to slide back and forth. The crew consisted of 15 (pilot, copilot, radar/bombardier, navigator, flight engineer, two radiomen, three forward gunners, and five rear gunners). Four rest bunks were provided for relief. An extremely heavy defensive armament was to be provided, consisting of five 37-mm cannon and ten 0.50-inch machine guns. These guns were to be distributed among four retractable turrets and a radar-directed tail turret. The guns were to be remotely directed by gunners situated at sighting stations distributed throughout the fuselage.

The B-36 mockup was inspected on July 20, 1942. The Mockup Committee felt that the aircraft carried too many guns and crew members to meet the 10,000 mile range requirement, and recommended that drastic reductions be made in the defensive firepower. However, some people on the committee felt that such changes would render the B-36 tactically useless, making it little more than a "flying laboratory" like the Douglas XB-19. If such reductions were actually necessary, the USAAF threatened to recommend the cancellation of the entire B-36 project and the diversion of funds to more productive bomber programs. The Mockup Committee compromised and eventually agreed to delete only the "less necessary" items of equipment from the aircraft. This reduced weight and saved the B-36 project from cancellation at that time.

In August of 1942, the San Diego plant was very heavily involved with work on the PBY and B-24, and Consolidated recommended that the XB-36 project be shifted from its San Diego, California plant to its new government-leased plant in Fort Worth, Texas. Although the USAAF approved this plan, it caused a delay of several months in the XB-36 project, since all the drawings, the mockup, the engineers, and the tooling had to be moved from California to Texas. At Fort Worth, R. C. Seybold became chief of engineering and Herbert W. Hinkley became the XB-36 project engineer. However, progress on the B-36 at Fort Worth was rather slow because of the higher priority of the B-24 Liberator and later the B-32 Dominator.

In order to speed things up, Consolidated recommended that the USAAF place a production order for the B-36 right away, arguing that two years could be saved if preliminary work on production aircraft could be started right away without waiting for completion of the experimental planes. However, the war in the Pacific was going badly at the time, and the USAAF felt that it should devote its full effort to planes which could be ready for combat in a much more timely fashion, and the request was denied.

In the summer of 1942, the USAAF agreed to the development of a cargo version of the XB-36 under the designation XC-99, provided that at least one of the two experimental bombers could be produced at least 3 months ahead of the cargo plane.

On March 17, 1943, the Consolidated Aircraft Corporation merged with Vultee Aircraft, Inc, becoming the Consolidated Vultee Aircraft Corporation. This name was often truncated to "Convair", although this name did not become official until April 29, 1954, when Consolidated Vultee Aircraft Corporation became the Convair division of the General Dynamics Corporation.

In the spring of 1943, China appeared near collapse in its war against invading Japanese forces, and the USAAF was faced with the unpleasant prospect of the loss of bases in China from which it planned to launch B-29 raids against Japan. It might turn out that the longer-ranged B-36 would be the only means of attacking the Japanese home islands if bases nearer Japan could not be secured. However, the president of Convair complained that it would be difficult to obtain subcontractors for an order for only two planes and that the company would be in a position to pursue the project with much more vigor if a large-scale production order were promised. Consequently, on June 19, 1943, General Arnold directed that orders be placed for 100 production examples. The letter of intent was signed by Convair on July 23. Under the new schedule, the XB-36 prototype should be ready for flight by September 1944. The first production B-36 was due in August of 1945, with the last one being delivered in October of 1946.

In late 1943, the twin tails were replaced by a single tail, which was almost 47 feet tall.

Unfortunately, progress on the XB-36 was still slow. The first Pratt & Whitney R-4360-5P Wasp Major test engine was to have been delivered to Fort Worth in May of 1943, but design improvements delayed it until October. Wind tunnel tests had to be postponed until the spring of 1944 because of the higher priority of other projects. The Pratt & Whitney Wasp Major engines had turned out to be somewhat heavier than expected, and some consideration was given to the use of different engines such as the Lycoming BX liquid-cooled powerplant. However, work on the Lycoming BX was discontinued on the basis that it would demand manpower, facilities, and materials that could be much better used elsewhere.

By mid-1944, the military situation in the Pacific had improved materially. The Marianas campaign was near its end, and preparation was being made for the deployment of B-29s from these bases to attack the Japanese mainland. The B-29's difficulties were now well on their way to solution, and it was felt that a super long-range bomber was not now so urgently needed and the Air Force directed that Convair should devote its main effort to the B-32 program as a backup for the B-29. Although the B-36 project would still continue, it would now do so with a lower priority. The contract for the 100 B-36s still remained in effect, but no longer carried any priority rating.

Following the surrender of Germany and the end of the war in Europe, aircraft production contracts were drastically cut back. However, the contract for the B-36 was untouched. The enormous losses suffered in seizing island bases in the Pacific convinced that USAAF that there was still a definite need for a long-range bomber. In addition, the forthcoming atomic bomb would require a long-range delivery vehicle capable of retaliating against an enemy without the need for faraway forward bases. On August 6, 1945, General Arnold accepted the Air Staff's recommendation to keep the B-36 contract for a hundred planes intact. Funds from the cancelled B-32 program were transferred to the B-36 project. On August 9, an Air Staff conference recommended that four B-36 groups be included in the postwar USAAF.

Work on the XB-36 continued even after the Japanese surrender. By 1945, Convair was still having problems with the high weight of the Pratt & Whitney R-4360-25 engines. The need to add nose guns required an extensive rearrangement of the forward crew compartment. A mockup of the new nose section had been approved in late 1944. This new nose would be too late for the first prototype, but would be fitted to the second XB-36. The radio and radar equipment in the new nose promised to add considerable weight.

Labor strikes at Convair in October 1945 and February 1946 delayed the B-36 program by several months. On March 25, 1946, General Thomas Power indicated that structural limitations of the forthcoming XB-36 might actually make it useless.

The B-36 was to have been provided with the Sperry-built K-1 bombing system, which consisted of an AN/APQ-23 radar and A-1 electromechanical bombing computer. The AN/APQ-23 was essentially an APQ-13 search radar combined with a CP-16 computer. The system supplied range, azimuth, distance, and drift information to the crew. The AN/APQ-23 was eventually succeeded by the AN/APQ-24.

The first XB-36 (42-13570) was rolled out of the Fort Worth factory on September 8, 1945. It sat on massive single 110-inch diameter main wheels, which restricted it to only three runways in the USA which had sufficiently thick concrete to support the weight of the aircraft.

The first XB-36 took off from Fort Worth on its maiden flight on August 8, 1946, remaining in the air for 37 minutes. It was piloted by Beryl A. Erickson and G. S. "Gus" Green, assisted by seven other crew members. It was the heaviest and largest landplane ever to fly up to that time. Flight tests turned up problems with the wing flap actuating system, the engine cooling was poor, and turbulent airflow off the wings caused propeller vibration which adversely affected the wing structure. The aircraft's overall performance fell below the original expectations. Engine cooling was a problem which resulted in the inability of the XB-36 to maintain altitudes over 30,000 feet for any extended period of time. The range was too short and the speed was too low. Besides the known structural limitations, the XB-36 had the single-wheel landing gear and carried only a minimum number of components, and lacked the nose armament that had been planned for the second XB-36. There were also problems with the aluminum wiring that had been fitted to save weight in place of the more reliable but heavier copper.

On December 12, 1946, General Kenny, head of the Strategic Air Command, believing the B-36 to be inferior to the B-50, suggested that the B-36 contract be reduced to only a few service test aircraft. However, neither the Air Staff nor General Nathan Twining agreed with this assessment, arguing that the B-36 should not be judged solely on the performance of the XB-36 which had just started its flight testing. General Carl Spaatz, the commander of the USAAF, agreed with General Twining, and the B-36 contract was spared.

On March 26, 1947, a hydraulic retraction cylinder failed just after takeoff, which caused engine number 4 to catch fire. After spending a few hours in the air to burn off excess fuel, pilots Erickson and Green managed to bring the crippled bomber safely in for a landing.

After being grounded for modifications, the XB-36 was flown for 160 hours by pilots of the USAAF Air Materiel Command. It was then returned to the contractor for further testing. Convair pilots made 53 test flights with the XB-36, logging a total of 117 flying hours.

In June of 1948, the single-wheel main undercarriage was replaced by a four-wheel bogie-type undercarriage, which was to be standard on production models. Each wheel had a 56 inch diameter. This reduced the runway thickness requirements. In addition, 3500 hp R-43660-41 engines were fitted. The plane was then redesignated YB-36A. It was reflown in this configuration in June of 1948.

The YB-36A was then turned over to the USAF in June of 1948, one week before the scheduled delivery of the first production B-36As. It had limited operational value and was used by the Strategic Air Command primarily for training. It was soon returned to Convair-Fort Worth, where it sat idly out in the open for the rest of 1948 and much of 1949. It was tested briefly with a track-type undercarriage in 1950. The aircraft was taken back on charge by the USAF at Wright Patterson AFB in August of 1950. However, the Air Force concluded that it would be too costly to bring it up to production standards, and the airplane was returned to Fort Worth and put in storage. It was officially retired on January 30, 1952, and towed over to a field at the north end of the Fort Worth plant. Engines and equipment were removed and the plane sat out in the open for five years. It was eventually towed across the runway to Carswell AFB and used as a prop in the base's firefighting program.

The second prototype, which was designated YB-36 (42-13571), had been chosen as the production prototype on April 37, 1945. It had the new high-visibility canopy with the raised roof and redesigned forward crew compartment, which became a standard production feature. The XB-36's poor cockpit visibility had been noted by the test pilots, but engineering studies on an improved cockpit layout had begun as early as June of 1945. The new crew compartment enabled nose armament to be fitted, which was added at Air Force insistence because of experience during the war which had shown that American bombers had been especially vulnerable to frontal attacks. The new cockpit covered the pilot, co-pilot, and flight engineer. The flight engineer now faced aft, looking towards the engines whose status he was responsible for monitoring. The turbo superchargers were more efficient. However, the YB-36 still had the original single-wheel undercarriage. It had been chosen as the production prototype on April 37, 1945. It was equipped with few components, but had many configurations so far approved. The YB-36 took off on its maiden flight on December 4, 1947, with Beryl Erickson again at the controls. It easily outperformed the XB-36, and during its third flight, it reached an altitude of more than 40,000 feet.

The YB-36 was turned over to the USAF on May 31, 1949. It was returned to Convair in October of 1950 to be fitted for reconnaissance, and was redesignated RB-36E. In the spring of 1957, it was placed in the Air Force Museum at Wright-Patterson AFB in Ohio. However, it was scrapped in 1971 when the new museum facility was built. However much of the scrapped aircraft was saved by collector Walter Soplata and is now stored on his land in Ohio.

Serials of XB-36 and YB-36:

42-13570	Consolidated XB-36
42-13571	Consolidated YB-36

Specification of Convair XB-36:

Engines: Six 3000 hp Pratt & Whitney R-4360-25 Wasp Major air cooled radial engines. Performance: Maximum speed 346 mph at 35,000 feet. Cruising speed 216 mph. Initial climb rate 1740 feet per minute. An altitude of 25,000 feet could be attained in 42 minutes. Service ceiling 36,000 feet. Absolute ceiling 38,000 feet. Range 9500 miles with 10,000 pounds of bombs, 3850 miles with 77,784 pounds of bombs. Weights: 131,740 pounds empty, 276,506 pounds gross. 19,976 gallons of fuel. Dimensions: Wingspan 230 feet 0 inches, length 162 feet 1 inches, Height 46 feet 8 inches, wing area 4772 square feet. Armament: No defensive armament fitted. Normal bomb load up to 72,000 pounds.

Joe Baughert

Sources:

  1. United States Military Aircraft Since 1909, Gordon Swanborough and Peter M. Bowers, Smithsonian, 1989.
     
  2. Post-World War II Bombers, Marcelle Size Knaack, Office of Air Force History, 1988.
     
  3. General Dynamics Aircraft and their Predecessors, John Wegg, Naval Institute Press, 1990.
     
  4. American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday, 1982.
     
  5. Convair B-36: A Comprehensive History of America's "Big Stick", Meyers K. Jacobsen, Schiffer Military History, 1997.

 

 

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.B-36D

 

Personnel and equipment required to get and keep a B-36 airplane in the air.

B-36J

 

 

 

The B-36A

 

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The B-36a

Twenty two B-36As were built in four production blocks. The -A model featured the domed canopy first seen on the YB-36 and a redesigned four-wheel main landing gear system which replaced the single wheel main landing gear of the two earlier aircraft (XB-36 and YB-36).

The first flight of the B-36A was on 28 August 1947. The -A model actually flew 6 months earlier than the YB-36, but this was because the first production B-36A (S/N 44-92004) was completed with just enough equipment to make a ferry flight to Wright Field, Ohio. Once at Wright Field the aircraft was used as a testbed for structural tests. These tests were often conducted to test maximum loads until structural failure occurred. Thus the first B-36A was destroyed.

Although the B-36A was technically a production aircraft, no defensive armament was installed. The -A model was used by the 7th Bomb Group at Carswell AFB, Texas for crew training and testing only.

TYPE
B-36A
 
Number Built/Converted
22
 
Remarks
Initial production block
 

SPECIFICATIONS
Span:
230 ft. 0 in.
Length: 162 ft. 1 in.
Height: 46 ft. 8 in.
Weight: 310,380 lbs. (max. gross weight)
Armament: Designed for ten .50-cal. machine guns and five 37mm cannon plus 72,000 lbs of bombs. (No defensive armament was actually installed)
Engines: Six Pratt & Whitney R-4360-25 radials of 3,000 hp. each (takeoff power)
Crew: 15

PERFORMANCE
Maximum speed:
345 mph. at 32,000 ft.
Cruising speed: 202 mph.
Range: 3,380 miles with 10,000 lbs. bomb load. (estimated combat radius); 9,136 mile ferry range
Service Ceiling: 39,100 ft.

The first B-36A-1-CF, 44-92004 was the second B-36 to fly. It first flew on August 28, 1947, four months before the YB-36. It made one flight in the vicinity of the Convair plant at Fort Worth, during which it was photographed extensively. Two days later it was flown to Wright Field in Ohio for structural testing. It is seen here on its flight to Dayton on August 30 with Col. Thomas P. Gerrity and Beryl Erickson at the controls. Col. Gerrity was one of the Toms of the Tom-Tom project.

The Air Force Museum

 

Convair B-36A Photo Archive

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B-36A-10-CF S/N 44-92013. This aircraft completed a simulated attack on Hawaii by flying a non-stop round-trip from Fort Worth, Texas on 13-15 May 1948

The first -A model built

B-36A-10-CF S/N 44-92015 (foreground) and B-36A-15-CF S/N 44-92023 (in flight)
The first B-36A-1-CF, 44-92004
The third B-36A-1-CF, 44-92006 was assigned to service testing at Wright Field.
The first production model of the B-36 lacked gun turrets and bombing systems. They were really just huge training airplanes.

The initial production version was the B-36A. The first production B-36A (44-92004) retained the R-4360-25s of the two prototypes. It flew for the first time on August 28, 1947, actually beating the second XB-36 into the air by four months. Beryl Erickson was again at the controls. Although it had been decided that production B-36s should carry a defensive armament of sixteen 20-mm cannon, no armament was actually fitted to this aircraft. However, an AN/APQ-23 bombing navigational radar was installed. This aircraft was only fitted with enough equipment for a flight to Wright Field in Ohio, where it was permanently grounded so that it could be structurally tested to destruction. It was permanently designated as YB-36A.

On December 12, 1946, General George S. Kenney, the commander of SAC since April of 1946, suggested that the procurement contract for 100 B-36s be reduced to only a few service-test aircraft. He believed the B-36 to be inferior to the Boeing B-50. Among the shortcomings of the B-36 were an effective range of only 6500 miles, an insufficient speed, and a lack of protection for the fuel load. However, neither the Air Staff nor Lt.Gen. Nathan F. Twining, the commander of the Air Materiel Command agreed with this assessment. They felt that the problems that had been experienced with the B-36 were normal at this stage in its development and that they could eventually be solved given sufficient time. In any case, the B-36 was the only long-range nuclear bomber available until the Boeing B-52 was ready, which at that time was not expected until 1953 at the earliest. General Carl Spaatz, who was now the commander of the USAAF, agreed with General Twining, and the B-36 contract was retained.

In August of 1947, shortly after the creation of the independent Air Force, General Hoyt Vandenberg, Deputy Chief of Air Staff, set up a USAF Aircraft and Weapons Board to determine which weapons would best support the Air Force's long-term plans. Because of the atomic bomb, strategic bombing took precedence. At that time, the B-36 was the only bomber capable of carrying out nuclear retaliation against an enemy without the need for overseas bases. However, at that time the supply of atomic bombs was still sparse, and plans had to be made for the possible use of conventional bombs. Many members of the Board felt that the B-36 was obsolete and should be cancelled in favor of fast jet bombers. However, this strategy was inherently risky since these jet bombers promised to have insufficient range and in any case would not be available for years. Still others wanted to try and improve the performance of the B-36 by re-engining it with the VDT engine and use it as an all-purpose bomber capable of delivering both conventional and nuclear weapons. Others thought that the Boeing B-50 would be a better choice because it was faster and could also get greater speed and range by being re-engined with the VDT engines. After prolonged debate, it was decided to stick with the basic B-36 as a special purpose nuclear deterrent bomber. The B-36 would remain in service until replaced by the B-52. At that time, it was thought that 100 B-36s would be enough, and no further procurement was anticipated.

A further 21 B-36As were completed (44-92005/92025). None of them were fitted with any armament either, at least initially. Nineteen of them were delivered to the 7th Bombardment Group (Heavy) which was based at Carswell AFB, located just across the field from the Convair factory at Fort Worth. The first delivery was on June 26, 1948. The last B-36A was accepted in February 1949. They were used exclusively for training and crew conversion.

On the night of April 8-9, 1948, B-36A 44-92013 made an extended flight of 33 hours 10 minutes, shuttling between Fort Worth and San Diego three times without stopping. It carried a 10,000 pound bomb load which was dropped midway from 25,000 feet on the Air Force Bombing Range at Wilcox, Arizona. The total distance flown was 6922 miles. In May of 1948, another long range flight was made by the same plane, a round trip of 8062 miles lasting 33 hours 8 minutes. On June 30, 1948, A B-36A dropped 72,000 pounds of bombs during a test flight.

In early 1950, Convair began conversion of the B-36As to the reconnaissance configuration. Included in the conversions was the sole YB-36 (42-13571). These were all redesignated RB-36E. The six R-4360-25 engines were replaced by six R-4360-41s--the more powerful engines already installed in the B-36Bs. They were also fitted with the four J47 turbojets that had initially fitted to the B-36D. They were equipped with K-17C, K-22A, K-38, and K-40 cameras. The converted B-36As also received some of the B-36B's more advanced electronics. Its normal crew was 22, which included 5 gunners to man the 16 M-24A-1 20-mm cannon. The last conversion was completed in July of 1951.

 

Serials of B-36A:

44-92004/92006	Consolidated B-36A-1-CF Peacemaker
44-92007/92011	Consolidated B-36A-5-CF Peacemaker
44-92012/92017	Consolidated B-36A-10-CF Peacemaker
44-92018/92025	Consolidated B-36A-15-CF Peacemaker

Specification of Convair B-36A:

Engines: Six Pratt & Whitney R-4360-25 Wasp Major air cooled radial engines, each rated at 3250 hp for takeoff and 3000 hp at 40,000 feet. Performance: Maximum speed 345 mph at 31,600 feet. Cruising speed 218 mph. Stalling speed 113 mph. Initial climb rate 1447 feet per minute. An altitude of 20,000 feet could be attained in 53 minutes. Service ceiling 39,100 feet. Combat ceiling 35,8000 feet. Combat radius 3880 miles with 10,000 pound bombload. Ferry range 9136 miles. Total mission time 35.6 hours. Takeoff run 6000 feet at sea level. Takeoff run over 50-foot obstacle 8000 feet. Weights: 135,020 pounds empty, 212,800 pounds combat, 311,000 pounds maximum. Dimensions: Wingspan 230 feet 0 inches, length 162 feet 1 inches, Height 46 feet 8 inches, wing area 4772 square feet. Armament: No defensive armament initially fitted. Maximum bomb load 72,000 pounds

Joe Baugher

Sources

  1. United States Military Aircraft Since 1909, Gordon Swanborough and Peter M. Bowers, Smithsonian, 1989.
     
  2. Post-World War II Bombers, Marcelle Size Knaack, Office of Air Force History, 1988.
     
  3. General Dynamics Aircraft and their Predecessors, John Wegg, Naval Institute Press, 1990.
     
  4. American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday, 1982.
     
  5. Convair B-36: A Comprehensive History of America's "Big Stick", Meyers K. Jacobsen, Schiffer Military History, 1997.

 

 

The B-36B

The Nuclear Bomber

 

Click on Picture to enlarge

The B-36B

Seventy three B-36Bs were ordered by the US Army Air Forces and assigned 1944 serial numbers. However, the first -B model didn't fly until 8 July 1948 after the formation of the USAF as a separate service. Unlike the B-36A, the B-36B was fitted out as a combat ready aircraft with sixteen 20mm cannons installed in eight remote-controlled turrets. The maximum bomb load was 72,000 lbs., but the aircraft was capable of an overloaded bomb capacity of up to 86,000 lbs. for shorter duration missions.

The -B model Peacemaker was equipped with a more powerful version of the Pratt & Whitney R-4360 radial. Each engine generated 500 more horsepower than the earlier version and resulted in a maximum speed increase for the B-36 up to 381 mph. Avionics upgrades included an assortment of offensive and defensive radar equipment.

The B-36B became operational at Carswell AFB, Texas in 1948 with the 7th Bomb Group. On 7-8 December 1948, a B-36B flew a round-trip practice mission from Carswell AFB to Hawaii. The aircraft averaged 228 mph. during the 35+ hour mission. Although the aircraft had great range, the slow cruising speeds at combat weight (about 225,000 lbs.) caused the entire B-36 program to be criticized as out dated in the post-WWII era of jet development. The debate over the projected combat effectiveness of the B-36 was very intense in the years immediately following WWII when defense spending was minimal. The US Navy, in particular, was a strong opponent of B-36 procurement.

During the -B model production run, the USAF authorized the addition of 4 jet engines mounted in two outer wing nacelles. The jets were an attempt to improve the performance of the B-36 by increasing the maximum speed and altitude for the aircraft. Most of the B-36B fleet was retrofitted with the jet engine modification and redesignated B-36D or RB-36D.

TYPE
B-36B
Number Built/Converted
73
Remarks
Initial production block
 

SPECIFICATIONS
Span:
230 ft. 0 in.
Length: 162 ft. 1 in.
Height: 46 ft. 8 in.
Weight: 328,000 lbs. (max. gross weight)
Armament: Sixteen 20mm cannons plus 72,000 lbs of bombs.
Engines: Six Pratt & Whitney R-4360--41 radials of 3,500 hp. each (takeoff power)
Crew: 15

PERFORMANCE
Maximum speed:
381 mph. at 34,500 ft.
Cruising speed: 202 mph.
Range: 8,175 miles with 10,000 lbs. bomb load.; 8,770 mile ferry range
Service Ceiling: 42,500 ft.

 

The B-36B was the first model to be equipped with combat systems.

The Air Force Museum

 

Click on Picture to enlarge

The insignia red (FS 36116) tail and wingtips of Convair B-36B, 44-92033 indicate that it is one of 18 B-36s assigned to the GEM program. The GEM program investigated the operation of the B-36 in the extremely cold conditions of the forward bases at Goose Bay, Labrador, Limestone, Maine, and Fairbanks, Alaska. The large red surfaces were intended to make the airplane easier to find if it went down on ice or snow in arctic regions.
Scale models of the B-36 and V-2 rocket are examined by Brigadier General H, Saylor, right, assisted by Dr. R. W. Porter, GE engineer, while Colonel H. M. Toftoy looks on.
Note the pairs of gun turrets on the forward and aft fuselage. The cockpit canopy does not exactly resemble the production unit.
This photograph of Convair B-36B, 44-92033 may have been taken with a red filter to make the red areas on the wingtip and tail appear so bright in comparison to other pictures of GEM B-36s that appear below.
 The fourth B-36B-1-CF, 44-92029 crashed at Carswell AFB on February 8, 1955. It was knocked down by windshear while practicing landings.
A B-36B heading to a flyover of Chicago on July 3, 1949. The bulges visible on the top of the wing inboard of the engine nacelles were added to make room for the four-wheeled main landing gear.
Storm clouds loom over Carswell AFB flightline in 1949.
 B-36B of the 7th Bomb Group runs up its engines while visiting Fairfield-Suisun Air Force Base (now Travis AFB) on May 14, 1950.
B-36B-1-CF, serial 44-92036, which has been modified with a pair of large pods on either side of the fuselage.
The pods were used to carry extra built-up R-4360 radial engines to deployment bases.

The first full-scale production version of the B-36 was the B-36B. The B-36B differed from the B-36A in having six 3500 hp R-4360-41 Wasp Major engines with water injection. These engines had 500 more horsepower than the -25 engine, which enabled the B-36B to take off within a shorter runway distance and yielded slightly better performance at both high and cruising speeds. The B-36B had more and better electronic equipment, including the AN/APQ-24 bombing/navigation radar (replacing the APG-23A of the B-36A). The B-36B could carry up to 86,000 pounds of bombs (a 14,000 pound increase over the capacity of the B-36A). The gross weight was 328,000 pounds.

In addition, the B-36Bs were equipped from the start with six remotely-operated retractable turrets, each equipped with a pair of M24A-1 20-mm cannon, plus two more M24A-1 20-mm cannon each in nose and tail turrets. This was the most formidable armament yet fitted to any warplane. The six retractable turrets were mounted in pairs on the upper fuselage behind the cockpit and in dorsal and ventral positions on the rear fuselage. They were mounted on platforms which could be retracted or extended by means of motors via a pair of metal legs with joints which allowed the turrets and their platforms to be folded down or up. The turrets and their platforms were housed behind sliding doors when not in use. When ready for firing, the doors were opened and were slid to the side and the platforms were raised into position. Each 20-mm gun carried 600 rounds of ammunition, with the exception of the nose turret guns which had only 400 rounds each. Each gun had a cyclic rate of fire of between 750 and 850 rounds per minute. The turrets were aimed remotely by gunners operating computing optical gunsights. The nose turret was directed by a hemispheric optical sight mounted inside an installation situated in the nose that was offset below and to the right of the nose center. The six retractable gun turrets were directed by yoke or pedestal sights mounted at six side blisters (two blisters in the forward crew compartment, four blisters in the rear). The tail guns were directed by an AN/APG-3 radar, with the sighting station located in the rear of the aft crew compartment. Unlike in the B-29 and B-50, a separate sight was slaved to each turret, and control of the turrets could not be passed back and forth between gunner stations.

The optical sighting station that directed the retractable fuselage turrets were situated inside hemispherical blisters. Each upper and lower visual sighting station included a reflector sight, sun filters, and free gyroscopes to transmit target lead data to the fire control computer. Each sighting station had a ring-and-bead sight as an emergency backup in case the computing system failed. Yoke-type sights were situated in the upper blisters, pedestal-type sights in the lower blisters.

The nose sighting station was a horizontally-mounted, double-prism periscopic sight that gave the gunner a complete hemisphere of vision when sighting through the eyepiece. However, the nose turret itself was limited to only 60 degrees in azimuth and slightly less in elevation/depression. The sight had at its forward end a spherical glass dome head which projected through the nose of the B-36. Rotation of the gunner's hand grips positioned scanning prisms located in a prism head.

The radar-aimed tail turret could be aimed at up to 40 degrees off centerline, either in azimuth or to the left or right. The APG-3 radar in the tail provided target range, azimuth, and elevation and angular speed relative to the bomber to the sighting station at the rear of the aft crew compartment. It was more accurate than the visual sights and could be used at night or in bad weather. The radar in the tail automatically swept back and forth until it located a target. The gunner then manually locked onto the target by taking the antenna out of its sweep mode. From that point on, the fire control system automatically tracked the target, ignoring any other targets that might be present.

Each of the sighting stations was provided with a separate electromechanical computer which made the calculations needed for a firing solution. The gunner sighted directly on the target, and the computer sent instructions to the turrets to aim it in the correct direction. The computer took account of the target's range and velocity with respect to the bomber and the rate of change of the target's azimuth and elevation. Each gunner manually inputted the bomber's current altitude and airspeed.

The crew of the B-36B was normally fifteen, a pilot, copilot, radar operator/bombardier, navigator, flight engineer, two radiomen, three forward gunners, and five rear gunners.

The first B-36B took off on its maiden flight on July 8, 1948. The performance was much better than expected. An average cruising speed of 303 mph could be maintained. At its combat weight of 227,000 pounds, the B-36B had a top speed of 381 mph and a service ceiling of 42,500 feet.

The B-36B was equipped with the Sperry-built K-1 bombing system. The earliest version of the K-1 was little more than a refined AN/APQ-24. The heart of the system was an AN/APS-23 radar and a Farrand Y-1 optical bombsight, both coupled with an A-1 electromechanical bombing computer. The system could use either its radar or an optical bombsight for bomb aiming and dropping. The search radar was the AN/APS-23, built by Western Electric. A vertical retractable periscope bombsight, the Farrand Y-1, was an integral part of the K-1 system. It made it unnecessary to use an optically-flat glass bomb-sighting window. The Sperry SRC-1 bombing/navigation computer (sometimes known as A-1 or AN/APA-59) operated by determining the relative position of a recognizable landmark and tracked the landmark either optically or by radar. It compensated automatically for crosswinds. The operator centered the crosshairs on the aiming point and allowed them to drift away under the influence of crosswinds. At a particular point, the operator then moved the crosshairs back to the aiming point and the computer determined the wind values. The computer then used this value to compensate for both evasive maneuvers and crosshair corrections. The entire system continuously computed and displayed ground speed, ground track bearing, wind velocity and direction and the aircraft's latitude and longitude positions. The APQ-24 allowed the B-36 to take evasive action during its bomb run, which was not possible for US bombers of World War 2, which had to fly straight and level over their targets.

18 of the B-36Bs could carry the remotely-controlled Bell VB-13 "Tarzon" bomb (2 bombs per aircraft). This was a free-falling weapon based on the British "Tallboy" bomb of World War 2. It was 25 feet long, 54 inches in diameter, and weighed 12,000 pounds. It was cigar shaped, with two lift shrouds, one annular shroud around the center of gravity and the other an octagonal shroud at the end. The Tarzon had a rudder and elevator controlled by radio and four ailerons gyro-stabilized by pneumatic controls, which could be used to guide the bomb both in range and azimuth during its fall. It was equipped with a flare in its tail, and an observation post was installed in the belly of the bomber where a controller could guide the bomb to its target by using a joystick. Guidance was entirely visual, and the bomb could not be dropped through overcast.

The B-36Bs were first assigned to the 7th Bombardment Group at Carswell AFB (which already had B-36As, the first planes arriving in November of 1948. By the end of 1948, there were 35 B-36s in service with SAC at Carswell AFB.

On December 5, 1948, a long range mission of 4275 miles was flown at high altitude. Except for climb and descent, an average cruising speed of 303 mph was maintained during the the entire 14 hour flight at 40,000 feet. This was surpassed during a similar mission on December 12, when the average speed rose to 319 mph.

On December 7-8, 1948, a 7th BG B-36B flew a 35 1/2 hour round-trip simulated bombing mission from Carswell to Hawaii. On the way, the aircraft's 10,000 pound bombload was dumped in the ocean a short distance from Hawaii. The total distance flown exceeded 8000 miles.

A second unit, the 11th Bombardment Group (Heavy) became operational at Carswell with the B-36B.

On January 20, 1949, five B-36Bs from Carswell AFB participated in a flyover of Washington, DC to celebrate the inauguration of Harry Truman as President of the United States.

On January 29, 1949, a B-36B piloted by Major Stephen Dillon established a record bomb lift by taking a pair of dummy 42,000 lb. Grand Slam bombs aloft at Muroc AFB. The first bomb was released at an altitude of 35,000 feet, the second from 40,000 feet.

Eleven B-36s participated in an aerial demonstration and static display at Andrews AFB, Maryland, where President Truman personally inspected the aircraft on February 15.

In March of 1949, a B-36B was used to establish a distance record of 9600 miles flown in 43 hours 37 minutes, carrying a 10,000-pound bombload for 5000 miles. The plane flew a course across the USA from Fort Worth to Minneapolis and Great Falls, Montana and then turned and flew to Key West, Florida where President Truman was vacationing. On the return trip, the bombload was released into the Gulf of Mexico, and the plane flew back to Great Falls and Spokane, Washington, before returning to Fort Worth.

The last B-36B was accepted in September of 1950.

From the outset, the B-36B aircraft had undergone a steady increase in weight which had a detrimental effect on performance. The remotely-controlled turrets and the 20-mm cannon were quite complex and were prone to frequent failures. The defensive armament system was designed and built by General Electric. At first, defects with both the gun and the turret postponed the system's installation in the B-36, resulting in the B-36As initially being delivered without any armament fitted. Once the guns were installed, a lack of 20-mm ammunition delayed the start of testing until mid-1949. As late as February of 1950, the commander of the 8th Air Force was complaining that there was little point in driving a B-36 around carrying a lot of guns that didn't work.

Many of the B-36B's initial problems resembled those of any other new and complex aircraft. Parts shortages were acute, and it was often necessary to cannibalize some B-36Bs to keep others flying. Ground support equipment such as empennage stands, dollies, and jacks were continually in short supply. The B-36B aircraft were in a constant state of flux, either being reconfigured or awaiting modification. In reality, full operational capability was not achieved until 1952.

Of the 73 B-36Bs built, 64 were converted to B-36D configuration with the addition of four General Electric J47-GE-19 turbojets paired in pods underneath the outer wings. They were redelivered with jets by February 1952

Serials of B-36B:

44-92026/92037	Consolidated B-36B-1-CF Peacemaker
44-92038/92049	Consolidated B-36B-5-CF Peacemaker
44-92050/92064	Consolidated B-36B-10-CF Peacemaker
44-92065/92079	Consolidated B-36B-15-CF Peacemaker
44-92080/92087	Consolidated B-36B-20-CF Peacemaker
44-92088/92094	Consolidated B-36B Peacemaker
44-92095/92098	Consolidated B-36B Peacemaker

Specification of Convair B-36B:

Engines: Six 3500 Pratt & Whitney R-4360-41 Wasp Major air cooled radial engines. Performance: Maximum speed 381 mph at 34,500 feet. Cruising speed 202 mph. Initial climb rate 1510 feet per minute. Service ceiling 42,500 feet. Combat ceiling 38,800 feet. Combat radius 3740 miles. Total mission time 42.43 hours. 8175 miles range. Weights: 140,640 pounds empty, 227,700 pounds combat, 311,000 pounds maximum takeoff. Dimensions: Wingspan 230 feet 0 inches, length 162 feet 1 inches, Height 46 feet 8 inches, wing area 4772 square feet. Armament: Two 20-mm M24A1 cannon each in six retractable, remotely-controlled fuselage turrets, tail turret and nose mounting, with 92000 rounds of ammunition. Normal bomb load up to 72,000 pounds. Maximum bomb load 86,000 pounds

Joe Baugher

Sources:

  1. United States Military Aircraft Since 1909, Gordon Sqanborough and Peter M. Bowers, Smithsonian, 1989.
     
  2. Post-World War II Bombers, Marcelle Size Knaack, Office of Air Force History, 1988.
     
  3. General Dynamics Aircraft and their Predecessors, John Wegg, Naval Institute Press, 1990.
     
  4. American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday, 1982.
     
  5. Truman, David McCullough, Simon and Schuster, 1992.
     
  6. Bell Aircraft Since 1935, A. J. Pelletier, Naval Institute Press, 1992.
     
  7. Convair B-36: A Comprehensive History of America's "Big Stick", Meyers K. Jacobsen, Schiffer Military History, 1997
  8.  

 

 

The B-36C

 

Click on Picture to enlarge

The B-36C

Although no B-36C was ever built, the proposed design incorporated a radical change to the engine and propeller arrangement. The -C model was designed to use the Pratt & Whitney R-4360-51 Variable Discharge Turbine (VDT) engine. This engine drove a conventional propeller but also used the exhaust from the turbo-supercharger as a 'jet assist.' In order for the VDT concept to be used on the B-36C, the propellers were changed from pushers (on the trailing edge of the wing) to tractors (on the leading edge). The conventional propeller mounting allowed the engines to be 'turned around', thus allowing the turbine exhaust to be used for additional thrust. The propellers were mounted on nacelles which projected about ten feet forward of the leading edge of the wing. The estimated top speed of the -C model increased to 410 mph, an improvement of almost 30 mph. over the standard B-36B.

34 B-36Cs were ordered in late 1947; however, VDT engine was plagued by problems and development was eventually halted. Without the VDT engine, the B-36C program was canceled in mid 1948. The -C model order was changed to B-36Bs, accounting for the entire last production block (B-36B-15).

TYPE
B-36C
 
Number Built/Converted
0
Remarks
B-36 design with tractor props. and turbine exhaust 'jet assist'

Notes:

Serial numbers: 44-92065 to 44-92098 ordered as B-36C but built as B-36B

 

No B-36C was ever built.

The Air Force Museum 

 

One of the criticisms of the B-36A was that it was already obsolete before it had taken off on its first flight, and did not have the performance necessary to survive in hostile airspace against determined fighter attack. The B-36C was an attempt to cure some of the performance problems encountered by the B-36A.

The B-36C was to be powered by six 4300 hp Pratt & Whitney R-4360-51 variable discharge turbine (VDT, or turbocompound) engines. In the VDT engine, exhaust gases from the piston engine would pass through a General Electric CHM-2 turbosupercharger which featured a clamshell nozzle that could create a jet thrust by varying the size of the turbine exit. The variable discharge nozzle was to be operated by automatic control activated by a manifold pressure sensor.

Convair claimed that the VDT engine would give the B-36 a top speed of 410 mph, a 45,000 foot service ceiling, and a 10,000-mile range with a 10,100-pound bombload. Unfortunately, the use of these engines would require a change from a pusher to a tractor format, which would in turn require a major redesign of the entire aircraft.

The VDT engine had originally been proposed for a version of the Boeing B-50 four-engined bomber, which had been assigned the designation XB-54. In mid-1947, Convair proposed that 34 aircraft out of the original hundred that were ordered be completed as B-36Cs. To offset the cost of converting one B-36 to a prototype B-36C configuration, Convair suggested that three B-36s be cut from the current procurement contract. This project was approved by General Spaatz, Chief of Staff, in July of 1947.

Many people both inside and outside the USAF thought that the B-36 was already obsolete, and believed that fast jet bombers should be acquired instead. However, jet bombers were at that time still many years away, and in any case promised to have a much shorter range than the B-36. Others wanted to use the B-36 as an all-purpose bomber, one that would be capable of delivering a wide range of conventional as well as nuclear ordnance in tactical as well as strategic missions. Yet others favored the B-50 over the B-36 because of its higher performance and also because it was considerably cheaper. After much discussion, it was decided to retain the B-36 as a special-purpose bomber that would be used strictly for long-range nuclear attack, with the hope that the fleet of B-36s would eventually be replaced by the B-52 when it became available. Consequently, it was concluded that there was no real need for a VDT-equipped B-36 and that the retrofit with VDT engines would serve no purpose other than to delay the completion of the 100 B-36s already on order and to drive up costs still further. The VDT-powered B-36C prototype was cancelled on August 22, 1947.

The cancellation of the prototype did not stop Convair from going ahead and proposing on September 4, 1947 that the last 34 B-36s in the hundred-plane contract be completed as B-36Cs. Convair proposed that the extra cost of the production of tthe 34 B-36Cs could be met by reducing the overall order to only 95 B-36s. Convair claimed that the B-36Cs could be produced without delaying the current contract by any more than 6 months. It was even suggested that the remaining B-36A and B aircraft on the contract could be retrofitted to B-36C standards.

The Convair proposal was accepted at least in principle on December 5, 1947. However, the decision on whether to retrofit the 61 remaining B-36s as B-36Cs was deferred until later. As it turned out, the attempt to mate the VDT engine with the B-36 airframe failed completely. There were problems with the engine cooling requirements generated by the aircraft's high operating altitude, which degraded the engine's performance. The drop-off in engine power at high altitude made Convair's estimates for the performance of the B-36C completely unrealistic. The project was quietly dropped in early 1948.

Joe Baugher

Sources:

  1. United States Military Aircraft Since 1909, Gordon Swanborough and Peter M. Bowers, Smithsonian, 1989.
     
  2. Post-World War II Bombers, Marcelle Size Knaack, Office of Air Force History, 1988.
     
  3. General Dynamics Aircraft and their Predecessors, John Wegg, Naval Institute Press, 1990.
     
  4. American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday, 1982.
     
  5. Convair B-36: A Comprehensive History of America's "Big Stick", Meyers K. Jacobsen, Schiffer Military History, 1997.

 

 

The B-36D

 

Click on Picture to enlarge

The B-36D

The B-36D was basically a B-36B modified by the addition of four J47 jet engines mounted in two outboard wing pods. The jet pod design was 'borrowed' from the B-47 program with Boeing approval. The addition of jets increased the maximum speed of the B-36 to more than 400 mph.

In an effort to increase performance, the USAF initiated the Featherweight II program and later Featherweight III. Featherweight II eliminated non-essential interior equipment and Featherweight III eliminated defensive armament except for the tail turret and most of the fire control avionics.

Twenty two B-36Ds were built and an additional 64 B-36Bs were modified to B-36D specifications (86 aircraft total). The first flight of the -D model with J47 jet engines was 11 July 1949. The prototype B-36D initially flew with J35 jet engines on 26 march 1949; however, vibration problems required an external brace for the nacelle. During the modification, the J47 became available and these were installed in place of the J35s.

 
TYPE
B-36D
B-36D
Number Built/Converted
22
64 (cv)
Remarks
First 10 engine model
converted B-36B

SPECIFICATIONS
Span:
230 ft. 0 in.
Length: 162 ft. 1 in.
Height: 46 ft. 8 in.
Weight: 357,500 lbs. (max. gross weight)
Armament: Sixteen 20mm cannons plus 72,000 lbs of bombs. (Featherweight III aircraft had 2 20mm cannons.)
Engines: Six Pratt & Whitney R-4360-41 radials of 3,500 hp. each (takeoff power) and four General Electric J47-GE-19 turbojets of 5,200 lbs. thrust each
Crew: 13 for Featherweight III ; 15 otherwise

PERFORMANCE
Maximum speed:
406 mph. at 36,000 ft. (Featherweight III -D models could fly 418 mph)
Cruising speed: 225 mph.
Range: 7,500 miles with 10,000 lbs. bomb load.; 8,800 mile ferry range
Service Ceiling: 45,200 ft.

The Air Force Museum

 

Click on Picture to enlarge

The B-36D

The early versions of the B-36 had been criticized for insufficient maximum speed and for a too-long takeoff run. On October 5, 1948, Convair proposed that these problems could be addressed by the fitting of two pairs of turbojets in pods underneath the outer wings. These turbojets would be used for takeoff and for short bursts of speed during the bombing run, and would have only a minimal effect on the range.

These changes resulted in the B-36D version. The B-36D featured two pairs of General Electric J47-GE-19 turbojets in pods underneath the outer wings to assist the six R-4360-41 engines. These pods were quite similar to those fitted underneath the inner wing of the Boeing B-47 Stratojet. The jet engines increased the maximum speed to 435 mph and the ceiling to more than 45,000 feet. In addition, they reduced the takeoff run by almost 2000 feet.

Conversion of a B-36B to D configuration was authorized on January 4, 1949. The prototype B-36D was obtained by converting B-36B serial number 44-92057. It had four Allison J35-A-19 engines in the pods in place of the later J47-GE-19s. It flew for the first time on March 26, 1949. The last four B-36Bs on the original contract (44-92095/92098) were completed as B-36Ds. The modification was sufficiently successful that the USAF contracted for additional bombers as B-36Ds during FY 1949, and opted to modify existing B-36Bs to D configuration.

The first true production B-36D flew on July 11, 1949. The first B-36Ds were accepted by the USAF in August of 1950, and were initially sent to Eglin AFB for testing. By June of 1951 26 B-36Ds had been delivered. The last B-36D was accepted in August of 1951. A total of 81 B-36Ds were delivered to the USAF, 22 built as B-36Ds from the start, and 59 others were converted from B-36Bs.

The B-36D had a K-3A bombing and navigation system that replaced the B-36B's K-1 system. The K-3A permitted a single crew member to act as both radar operator and bombardier. The K-1 system had experienced its share of reliability problems, chiefly due to vacuum tube failures. A quarter of the B-36 mission aborts were caused by radar failures of one sort or the other. During later modernization programs, the K-1 system was replaced by the much more reliable K-3A system. This included the Farrand Y-3 periscope bombsight, an A-1A improved bombing/navigation computer, and an improved version of the Western Electric AN/APS-23 radar. The Sperry A-1A bombing computer could be used between altitudes of 4700 and 50,000 feet, at grounds speeds between zero and 760 knots. The Farrand Y-3 periscopic bombsight offered magnifications of up to 4 power with a 76 degree field of view. The sighting lens could be moved forward by 90 degrees, aft by 35 degrees, and laterally by 54 degrees in either direction. The Western Electric APS-23 radar was of an improved variety with a rapid scan antenna, high-definition radar scopes, data storage tubes that could hold an image on display for a considerable amount of time, K-band tunable radar heads, and flush-mounted antennae. It could scan either 360 degrees, or in 40 to 180 degree sector scans, with a range of five to 200 miles, using different pulse durations and pulse repetition frequencies. The 60 inch antenna could be rotated at up to 60 rpm. At 30,000 feet, large cities could be detected at a range of up to 200 miles and shipping could be detected at ranges of 50 to 100 miles. The APS-23 radar was equipped with anti-jamming features.

The B-36D featured AN/APG-32 radar to control the tail turret. The aircraft was fitted with snap-action split bomb-bay doors as opposed to the sliding type doors fitted to the preceding B-36As and Bs. These doors could open and close in only two seconds. Metal covered control surfaces were fitted, and bladder-type outer panel fuel cells were installed. Takeoff and landing weights were up to 370,000 and 357,000 pounds respectively. The maximum bombload was increased to 86,000 pounds, and the crew complement increased to 15.

The maximum bombload was 86,000 pounds, consisting of two 43,000-pound bombs. Smaller alternative loads consisted of three 22,000 pound bombs, four 12,000 pound bombs, 12 4000-lb bombs, 28 2000-lb bombs, or 132 500-lb bombs. Such loads were not equaled until the "Big Belly" B-52D modifications during the Vietnam War.

The B-36D had a crew of 15: commander, two pilots, two engineers, navigator, bombardier, two radio operators, and an observer forward (the first radio operator handled ECM while the second radio operator, the copilot, and the observer operated the three forward turrets. The rear compartment accommodated five gunners, including one for the AN/APG-3 (later AN/APG-32) radar controlling the tail turret.

On January 16, 1951, 6 B-36Ds were flown from Carswell AFB to the United Kingdom, landing at RAF Lakenheath after having staged through Limestone AFB in Maine. The flight returned to Carswell on January 20. This marked the first time that B-36s had flown outside US territory. A flight to French Morocco was made on December 3, when 6 B-36s of the 11th Bombardment Wing landed at Sidi Slimane, having flown nonstop from Carswell AFB.

Gradually, most of the problems with the B-36 were identified and corrected. An early major B-36 problem was leakage in the fuel system. In addition, the electrical system was unreliable and caused frequent fires. Improved containers and better sealants reduced fuel tank leakages. Changes in the electrical system reduced fire hazards during ground refuelling operations. Landing gear and bulkhead failures were almost totally eliminated.

However, even by October of 1951, the B-36D's defensive armament system was still performing poorly. In April of 1952, the Air Force ordered a series of gunnery missions to see if the cause of the failures could be determined. This test was completed in July. The K radar system was difficult to operate and maintain, and the training for the gunners was found to be inadequate.

In August and September of 1953, B-36s of the 92nd Heavy Bombardment Wing completed the first mass flight to the Far East, visiting bases in Japan, Okinawa, and Guam. This flight took place shortly after the hostilities ended in Korea, and was an effort to demonstrate US willingness to maintain operations in the Far East. On October 15 and 16, 1953, the 92nd Heavy Bomb Wing left Fairchild AFB in Washington for a 90 day deployment to Guam. This was the first time an entire B-36 wing had been deployed overseas.

The B-36 flew fairly well on just four or even three piston engines, so it was common practice to shut down some of the engines during cruise. The turbojets were normally used only for speed dashes over the target area or for takeoff.

Several B-36Ds were modified as lightweight, high-altitude aircraft by being stripped of all armament except the tail turret. All non-essential flying and crew comfort equipment was taken out. The crew was reduced to 13, 2 fewer than the standard B-36D. These planes were identified as Featherweight B-36D-IIIs. The Featherweight program was carried out in three phases: Model I, which included a general weight reduction effort, followed by Model II which further reduced weight but kept the defensive armament intact, and ended with Model III, which removed all the defensive armament, making it possible for the B-36 to reach altitudes in excess of 50,000 feet.

26 B-36Ds were built from scratch. In addition, some 64 B-36Bs were converted at Convair's San Diego facility to B-36D configuration. The last B-36Ds were taken out of service in 1957.

Serials of B-36D:

44-92095/92098	Consolidated B-36D-1-CF Peacemaker
			Originally ordered as B-36B.
49-2647/2654	Convair B-36D-5-CF Peacemaker
49-2655		Convair B-36D-35-CF Peacemaker
49-2656/2657	Convair B-36D-15-CF Peacemaker
49-2658/2663	Convair B-36D-25-CF Peacemaker
49-2664/2668	Convair B-36D-35-CF Peacemaker

Specification of Convair B-36D:

Engines: Six 3500 Pratt & Whitney R-4360-41 Wasp Major air cooled radial engines, plus four 5200 lb.st. General Electric J47-GE-19 turbojets. Performance: Maximum speed 439 mph at 32,120 feet. Cruising speed 225 mph. Initial climb rate 2210 feet per minute. Service ceiling 45,200 feet. Takeoff run 4400 feet, 5685 feet over 50-foot obstacle. Combat radius 3525 miles. 7500 miles range. Weights: 161,371 pounds empty, 250,300 pounds combat, 370,000 pounds maximum. Dimensions: Wingspan 230 feet 0 inches, length 162 feet 1 inches, Height 46 feet 8 inches, wing area 4772 square feet. Armament: Two 20-mm M24A1 cannon each in six retractable, remotely-controlled fuselage turrets, tail turret and nose mounting, with 9200 rounds of ammunition. Normal bomb load up to 72,000 pounds. Maximum bomb load 86,000 pounds

Joe Baugher

Sources:

  1. United States Military Aircraft Since 1909, Gordon Sqanborough and Peter M. Bowers, Smithsonian, 1989.
     
  2. Post-World War II Bombers, Marcelle Size Knaack, Office of Air Force History, 1988.
     
  3. General Dynamics Aircraft and their Predecessors, John Wegg, Naval Institute Press, 1990.
     
  4. American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday, 1982.
     
  5. Convair B-36: A Comprehensive History of America's "Big Stick", Meyers K. Jacobsen, Schiffer Military History, 1997.
  6.  

Click on Picture to enlarge

 

 

 

 

Two pairs of J-47 jet engines were introduced on the D-model of the B-36.

 

 

B-36F-5-CF 49-2683 on the old South Base flightline of Edwards Air Force Base. Behind it to the right are a Boeing C-97 Stratocruiser and B-47 Stratojet. On the left is an RB-36. Note the difference in the placement of the bomb bay doors on the RB-36. Rogers Dry Lake can be seen in the background.
The  Featherweight B-36 has no nose turret. It is parked on the Edwards Air Force Base flightline. In the background is a modified B-29 Superfortress, a B-52A Stratofortress, B-47 Stratojets and F-100 Super Sabres.

 

 

 

Two B-36F (II) of the 6th Bomb Wing (Heavy), fly low over the desert near their home base at Walker AFB, Roswell, New Mexico.  Each aircraft had a crew of 15 men, sixteen 20mm cannons in eight turrets, and carried a 43,500 lb. MK-17 Thermonuclear Weapon during EWO (Emergency War Order) operations.  Aircraft 92683 in the foreground has an oil leak on the right inboard engine as evidenced by two oil stains on the right stabilizer and elevator - a very common occurrence. Convair B-36, Boeing B-52B and B-47E at Eglin AFB firepower demonstration.

 

 

 

 

 

 

Click on Picture to enlarge

The MK-17 Thermonuclear (TN) Bomb.  This was the primary EWO weapon carried by the B-36 fleet during the 1950s.  The bomb was parachute retarded, weighed 43,500 pounds, and was 25 feet in length.  The bomb was carried in the two aft bomb bays, while a smaller 6,000 pound MK6 atomic bomb was carried in one of the forward bomb bays.

 

More About The B-36D

 

 

RB-36 Reconnaissance Bomber

 

Click on Picture to enlarge

RB-36D-10-CF 49-2688. Note the three electronics intelligence antennae under the fourth bomb bay. RB-36F-1-CF 49-2708 of the 99th Strategic Reconnaissance Wing on the ramp at Fairchild AFB.
RB-36 of the 99SRW (H) at Fairchild Air Force Base in 1953.

 

 

 

RB-36F-1-CF 49-2709 at Fairchild Air Force Base on August 28, 1956. The 99th has become a Heavy Bombardment Wing. RB-36F 49-2709 has had white anti-flash paint added to its undersides. The electronics intelligence antennae have been moved aft in accordance with Technical Order 1B-36(R)-216

In the early 1950s, the RB-36 was one of the primary intelligence gathering airplanes in the Air Force inventory. Where standard B-36 bombers had four bomb bays, the forward bomb bay of the RB-36 was converted to a pressurized camera compartment. The camera compartment was connected to the forward crew compartment by a tunnel through the turret bay and to the aft crew compartment by a tunnel through the bomb bays. The RB-36 was typically equipped with fourteen cameras with focal lengths up to 1200 mm. They used film that was up to 9 inches by 18 inches.

The pressurized sections of the B-36 were skinned with aluminum. The bomb bay and the gun turret bays were skinned with magnesium. RB-36s can be spotted by the shinier aluminum camera compartment with a pair of windows in front of the wing.

This picture shows the original bomb bay configuration of the RB-36F. The aft bomb bay was sealed and electronics intelligence equipment was housed in the space. Three electronics intelligence antennae were housed in radomes mounted on the underside of the bay. Photo flash bombs were housed in the second bomb bay and an extra fuel tank was installed in the third bomb bay. The second and third bays were equipped with a single pair of doors.

In June 1954, the primary role of the RB-36 fleet was changed to heavy bombardment. Technical Order 1B-36(R)-216 directed that the aft bomb bay should be converted to a functional bomb bay. The electronics intelligence gear and antennae were moved to the aft crew compartment. A short pair of doors covered the second bomb bay. The third and fourth bomb bays were equipped with a single pair of doors.

In the foreground is the pit that was used to load Republic RF-84K "Thunderflashes" into GRB-36D carrier airplanes of the Fighter Conveyer (FICON) squadron. FICON operations had been suspended in January 1956. The wedges served as permanent wheel chocks

 

 

The RB-36D

 

Click on Picture to enlarge

The RB-36D

The RB-36D was a reconnaissance version of the B-36D. The number 1 (forward) bomb bay was fitted with 14 cameras. The number 2 bay was used to carry up to eighty 100 lb. photo flash bombs for nighttime aerial photography. The 3rd bay could be equipped with a variety of additional equipment including a 3,000 gallon fuel cell for increasing the endurance of the aircraft. The last bay was equipped with electronic counter measures (ECM) gear.

Externally, the RB-36D was similar to the B-36D bomber version; however, the reconnaissance version had many more antennas and four large radomes: one forward of the nose landing gear and three more on the belly installed in the number 4 bomb bay.

About half of the RB-36Ds were later updated to Featherweight III specifications. This extended the range and increased the speed of the aircraft by reducing the overall aircraft weight. All defensive armament was removed except for the twin 20mm cannons in the tail along with most of the fire control avionics. The crew of the RB-36D Featherweight III aircraft was 19 rather 22 carried on the standard version.

During the mid-1950s, 10 RB-36Ds were modified as fighter conveyor aircraft (FICON). These aircraft were designed to carry an RF-84F in a modified bomb bay. The idea was to carry the reconnaissance fighter close to the area to be photographed, release it in flight, and later recover it in flight. (see the FICON section of the F-84F special projects )

 
TYPE
RB-36D
RB-36D
Number Built/Converted
17
7 (cv)
Remarks
First 10 engine model
converted B-36B

SPECIFICATIONS
Span:
230 ft. 0 in.
Length: 162 ft. 1 in.
Height: 46 ft. 8 in.
Weight: 357,500 lbs. (max. gross weight)
Armament: Sixteen 20mm cannons plus 80 T86 (AN-M46) 100 lb. photo flash bombs. (Featherweight III aircraft had two 20mm cannons.)
Engines: Six Pratt & Whitney R-4360-41 radials of 3,500 hp. each (takeoff power) and four General Electric J47-GE-19 turbojets of 5,200 lbs. thrust each
Crew: 19 for Featherweight III ; 22 otherwise

PERFORMANCE
Maximum speed:
408 mph.
Cruising speed: 225 mph.
Range: Approximately 10,000 miles
Service Ceiling: Approximately 50,000 ft.

The Air Force Museum

 

Convair RB-36D

Click on Picture to enlarge

The RB-36D was a specialized photographic-reconnaissance version of the B-36D. It was outwardly identical to the standard B-36D, but carried a crew of 22 rather than 15, the additional crew members being needed to operate and maintain the photographic reconnaissance equipment that was carried. The forward bomb bay in the bomber was replaced by a pressurized manned compartment that was filled with fourteen cameras. This compartment included a small darkroom where a photo technician could develop the film. The second bomb bay contained up to 80 T86 photo flash bombs, while the third bay could carry an extra 3000 gallon droppable fuel tank. The fourth bomb bay carried ferret ECM equipment. The defensive armament of sixteen 20-mm cannon was retained. The extra fuel tanks increased the endurance to up to 50 hours.

The standard RB-36D carried up to 23 cameras, primarily K-17C, K-22A, K-38, and K-40 cameras. A special 240-foot focal length camera was tested on 44-92088, the aircraft being redesignated ERB-36D. The long focal length was achieved by using a two-mirror reflection system. The camera was supposedly capable of resolving a golf ball at an altitude of 40,000 feet. This camera is now with the Air Force Museum at Wright Patterson AFB.

The first RB-36D (44-92088) made its initial flight on December 18, 1949, only 6 months after the first B-36D had flown. It initially flew without the turbojets. The RB-36D actually preceded the B-36D into service with SAC by a couple of months, the 28th Strategic Reconnaissance Wing based at Rapid City AFB (later renamed Ellsworth AFB) in South Dakota receiving its first RB-36D on June 3, 1950.

A total of 24 RB-36Ds were built. The Air Force carried all of these 24 aircraft on their records as RB-36D, but 7 of these RB-36Ds initially appeared on Convair records as B-36Bs. All were delivered to the 28th Strategic Reconnaissance Group at Rapid City, South Dakota beginning in June of 1950. Due to severe materiel shortages, the new RB-36Ds did not become operationally ready until June of 1951. The 24th and last RB-36D was delivered in May of 1951.

In contrast to what is said in some B-36 books and articles, no aircraft originally built as a B-36B was converted to RB-36D. The confusion might be due to Convair line records showing 44-92088/92094 as starting construction as B models, even though they did not leave the factory that way.

Some RB-36Ds were modified to the featherweight configuration, in which all but the tail guns were removed. The crew was reduced from 22 to 19. These aircraft were redesignated as RB-36D-III. Modifications were carried out by Convair from February 1954 to November 1954.

Serials of RB-36D:

44-92088/92094 Consolidated RB-36D-1-CF Peacemaker
Originally ordered as B-36B.
49-2686 Convair RB-36D-5-CF Peacemaker
49-2687/2693 Convair RB-36D-10-CF Peacemaker
2687 modified to GRB-36D.
2692 modified to GRB-36D.
49-2694/2697 Convair RB-36D-15-CF Peacemaker
2694 modified to GRB-36D
2695 modified to GRB-36D
2696 modified to GRB-36D
49-2698/2702 Convair RB-36D-20-CF Peacemaker
2701 modified to GRB-36D
2702 modified to GRB-36D
 

Joe Baugher

Sources:

  1. United States Military Aircraft Since 1909, Gordon Sqanborough and Peter M. Bowers, Smithsonian, 1989.
     
  2. Post-World War II Bombers, Marcelle Size Knaack, Office of Air Force History, 1988.
     
  3. General Dynamics Aircraft and their Predecessors, John Wegg, Naval Institute Press, 1990.
     
  4. American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday, 1982.
     
  5. Convair B-36: A Comprehensive History of America's "Big Stick", Meyers K. Jacobsen, Schiffer Military History, 1997.
     
  6. E-mail from Scott Deaver with correction on no B-36Bs being convierted to RB-36Ds.

 

 

 

The RB-36E

 

Convair RB-36E

Click on Picture to enlarge

The RB-36E was strictly a conversion program for modifying the YB-36 and 21 B-36As. The only -A model not converted was the first built, this aircraft was used for structural testing at Wright-Patterson AFB. The changes were essentially the same as the B-36B to RB-36D conversion; four jet engines were added in two outboard wing nacelles, the bomb bays were modified to accept cameras, photo flash bombs, additional fuel cells and electronic counter measures equipment. After conversion the aircraft were re-designated RB-36E.

TYPE
RB-36E
 
Number Built/Converted
22 (cv)
 
Remarks
Converted YB-36 (1) and B-36A (21)
 

SPECIFICATIONS
Span:
230 ft. 0 in.
Length: 162 ft. 1 in.
Height: 46 ft. 8 in.
Weight: 357,500 lbs. (max. gross weight)
Armament: Sixteen 20mm cannons plus 80 T86 (AN-M46) 100 lb. photo flash bombs. (Featherweight III aircraft had two 20mm cannons.)
Engines: Six Pratt & Whitney R-4360-41 radials of 3,500 hp. each (takeoff power) and four General Electric J47-GE-19 turbojets of 5,200 lbs. thrust each
Crew: 19 for Featherweight III ; 22 otherwise

PERFORMANCE
Maximum speed: 408 mph.
Cruising speed: 225 mph.
Range: Approximately 10,000 miles
Service Ceiling: Approximately 50,000 ft.

The Air Force Museum

 

In early 1950, Convair began conversion of the B-36As to the reconnaissance configuration. Included in the conversions was the sole YB-36 (42-13571). These converted planes were all redesignated RB-36E. The six R-4360-25 engines were replaced by six R-4360-41s--the more powerful engines already installed in the B-36Bs. They were also equipped with the four J47 jet engines that were fitted to the RB-36D. They were equipped with fourteen K-17C, K-22A, K-38, and K-40 cameras. It also received some of the B-36B's more advanced electronics. Its normal crew was 22, which included 5 gunners to man the 16 M-24A-1 20-mm cannon. The last conversion was completed in July of 1951.

Joe Baugher

Sources:

  1. United States Military Aircraft Since 1909, Gordon Swanborough and Peter M. Bowers, Smithsonian, 1989.
     
  2. Post-World War II Bombers, Marcelle Size Knaack, Office of Air Force History, 1988.
     
  3. General Dynamics Aircraft and their Predecessors, John Wegg, Naval Institute Press, 1990.
     
  4. American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday, 1982.
     
  5. Convair B-36: A Comprehensive History of America's "Big Stick", Meyers K. Jacobsen, Schiffer Military History, 1997.

 

 

The B-36F

 

Click on Picture to enlarge

Two B-36Fs

The B-36F was an improved version of the B-36D. More powerful Pratt & Whitney R-4360-53 radial engines of 3,800 horsepower each replaced the -41 engines of the -D model. The increased power allowed the -F to fly to a maximum speed of 417 mph.

Thirty four B-36Fs were built in 4 production blocks and carried 1949 and 1950 serial numbers. Various avionics improvements included an improved radar bombing system (K-3A) and a new defensive fire control radar system (AN/APG-32 and later AN/APG-32A). Chaff (radar reflective metallic strips) dispensers were also installed to confuse enemy radar by creating large/false radar returns.

Like most B-36 series aircraft, some -F models were modified to Featherweight II or III specifications. The Featherweight III program eliminated all defensive armament except for the two 20mm cannons in the tail along with most of the defensive fire control system.

One B-36F (S/N 49-2677) was modified for use as a carrier for the XB-58 test program. The main fuselage and wing structure was carried in the bomb bay.

 

TYPE
B-36F
 
Number Built/Converted
34
 
Remarks
Imp. B-36D with -53 radial engines

SPECIFICATIONS
Span:
230 ft. 0 in.
Length: 162 ft. 1 in.
Height: 46 ft. 8 in.
Weight: 357,500 lbs. (max. gross weight)
Armament: Sixteen 20mm cannons plus 86,000 lbs. of bombs (max. overload capacity) (Featherweight III aircraft had two 20mm cannons.)
Engines: Six Pratt & Whitney R-4360-53 radials of 3,800 hp. each (takeoff power) and four General Electric J47-GE-19 turbojets of 5,200 lbs. thrust each
Crew: 13 for Featherweight III ; 15 otherwise

PERFORMANCE
Maximum speed:
417 mph.
Cruising speed: 235 mph.
Range: 3,200 miles with 10,000 lb. bomb load (combat radius); 7,700 mile ferry range
Service Ceiling: 44,000 ft.

The Air Force Museum

 

Click on Picture to enlarge

Convair B-36F

The B-36F differed from the B-36D primarily in having more-powerful 3800 hp Pratt & Whitney R-4360-53 engines. Each of these engines generated 3800 hp--300 hp more than the engines of the B-36D. The B-36F also had improved radar and electronics countermeasures equipment. The K-3A radar system and the APG-32 gun laying radar were standard. A chaff dispenser was installed to confuse enemy radar. Top speed increased to 417 mph and service ceiling to 44,000 feet with a standard combat load and 264,300 combat weight.

The first B-36F (49-2669) took off on its maiden flight on November 18, 1950. The first B-36F was accepted in March of 1951. However, the first B-36Fs did not reach SAC until August of that year.

At first, the R-4360-53 engines of the B-36F were not entirely satisfactory because of excessive torque pressure as well as ground air cooling and combustion problems. However, these problems were resolved fairly quickly.

The last of 34 B-36Fs was manufactured in October of 1952, but the Air Force did not get its last B-36F until several months later.

A number of the new B-36Fs were modified as featherweight aircraft during 1954.

The Air Force ordered 24 long-range reconnaissance versions of the B-36F designated RB-36F. The first four RB-36Fs were accepted in May of 1951. The remaining were accepted between August and December of 1951.

Serials of B-36F:

49-2669/2675	Convair B-36F-1-CF Peacemaker
49-2677		Convair B-36F-1-CF Peacemaker
49-2678/2683	Convair B-36F-5-CF Peacemaker
49-2685		Convair B-36F-5-CF Peacemaker
49-2703/2711	Convair RB-36F-1-CF Peacemaker
				2707 used in FICON and TOM-TOM project tests.
					Redesignated JRB-36F after 1955.
49-2712/2721	Convair RB-36F-5-CF Peacemaker
50-1064/1073	Convair B-36F-10-CF Peacemaker
50-1074/1082	Convair B-36F-15-CF Peacemaker
50-1098/1099	Convair RB-36F-10-CF Peacemaker
50-1100/1102	Convair RB-36F-15-CF Peacemaker

Specification of B-36F:

Engines: Six 3800 Pratt & Whitney R-4360-53 Wasp Major air cooled radial engines, plus four 5200 lb.s.t. General Electric J47-GE-19 turbojets. Performance: Maximum speed 417 mph at 37,100 feet, 414 mph at 40,200 feet. Cruising speed 235 mph. Stalling speed 123 mph. Initial climb rate 2060 feet per minute. Service ceiling 44,000 feet. Combat ceiling 40,900 feet. Combat radius 3200 miles with 10,000 pounds of bombs. 7743 miles ferry range with 30,630 gallons of fuel. Weights: 167,647 pounds empty, 264,300 pounds combat, 370,000 pounds maximum. Dimensions: Wingspan 230 feet 0 inches, length 162 feet 1 inches, Height 46 feet 8 inches, wing area 4772 square feet. Armament: Two 20-mm M24A1 cannon each in six retractable, remotely-controlled fuselage turrets, tail turret and nose mounting, with 9200 rounds of ammunition. Normal bomb load up to 72,000 pounds. Maximum bomb load 86,000 pounds

Joe Baugher

Sources:

  1. United States Military Aircraft Since 1909, Gordon Swanborough and Peter M. Bowers, Smithsonian, 1989.
     
  2. Post-World War II Bombers, Marcelle Size Knaack, Office of Air Force History, 1988.
     
  3. General Dynamics Aircraft and their Predecessors, John Wegg, Naval Institute Press, 1990.
     
  4. American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday, 1982.
     
  5. Convair B-36: A Comprehensive History of America's "Big Stick", Meyers K. Jacobsen, Schiffer Military History, 1997.

The Air Force Museum

 

 

The RB-36F

 

The RB-36F was built as a reconnaissance version of the B-36F. The -F model was similar to the RB-36D, but differences included the same engine upgrade as the B-36F--the R-4360-53 of 3,800 horsepower and an improved defensive fire control radar system.

Twenty four RB-36Fs were built with 1949 and 1950 serial numbers in 4 production blocks. During the later part of the RB-36s service life, new reconnaissance aircraft became operational and the recon role for the RB-36 became secondary. The USAF began a modification program to give the RB-36 an increased offensive combat role. The reconnaissance cameras were retained in bomb bay number 1 (forward); however, bays 2-4 were stripped of all reconnaissance equipment and returned to actual bomb bays. The electronic counter measures (ECM) equipment housed in bomb bay number four was moved further aft.

One RB-36F was modified to test the Fighter Conveyor (FICON) concept. This aircraft was re-designated GRB-36F.

 
TYPE
RB-36F
 
Number Built/Converted
24
 
Remarks
Recon. version of B-36F
 

SPECIFICATIONS
Span:
230 ft. 0 in.
Length: 162 ft. 1 in.
Height: 46 ft. 8 in.
Weight: 357,500 lbs. (max. gross weight)
Armament: Sixteen 20mm cannons plus 80 Photo Flash Bombs for nighttime photography. (Featherweight III aircraft had two 20mm cannons.) In the mid-1950s, bomb bays 2-4 were refitted to carry bombs.
Engines: Six Pratt & Whitney R-4360-53 radials of 3,800 hp. each (takeoff power) and four General Electric J47-GE-19 turbojets of 5,200 lbs. thrust each
Crew: 19 for Featherweight III ; 22 otherwise

PERFORMANCE
Maximum speed:
417 mph.
Cruising speed: 235 mph.
Range: approximately 10,000 miles
Service Ceiling: above 50,000 ft.

The Air Force Museum

 

 

The B-36 & Parasite Fighter Programs:

 

The RB-36F  Tom-Tom

 

Click on Picture to enlarge

Project Tom-Tom

Early jet fighters had limited range and endurance, and several bizarre experiments were performed during the late 1940s and early 1950s to test the feasibility of enhancing jet fighter range by having them carried into the combat zone by either being towed behind bombers or by being stowed inside them. None of these range-extension experiments was more bizarre than "Project TOM-TOM", in which jet fighters were to be attached to the wingtips of large bombers such as B-29s or B-36s.

Two F-84Bs (46-641 and 44-661) were selected and modified for the initial tests. These two F-84Bs were redesignated EF-84B. The wingtips of the EF-84Bs were modified so that they could be attached to flexible mounts fitted to the wingtips of a specially modified EB-29A (serial number 44-62093). I have a photograph of this bizarre three-plane arrangement flying wingtip-to-wingtip, and you have to blink your eyes a couple of times to make sure that they are not fooling you.

As expected, this idea proved to be highly dangerous. The biggest problem was the extreme vortex that was generated at the wingtips of the EB-29A, which caused the attached parasites to roll violently. The entire three-plane EF-84B/EB-29A/EF-84B array crashed as a unit on April 24, 1953, killing all the crewmembers. The project was terminated shortly thereafter.

A parallel project had been undertaken with a pair of RF-84Fs (51-1848 and 51-1849) attached to wingtip hook-up assemblies on an RB-36F (49-2707). This particular RB-36F had been used in the FICON project and was reassigned to TOM-TOM. The RB-36F had articulated hookup arms attached to the wingtips, and the two RF-84Fs had articulated clamp assemblies on their wingtips. Tests began in mid 1952, and the first actual hook-ups were made in early 1953 with just one of the RF-84Fs. After the crash of the EB-29A/EF-84B combo, trials continued for a few months with this RF-84F/RB-36F/RF-84F array. Only a few hookup attempts were actually made, and wingtip vortices and turbulence always made this operation a very dangerous and difficult affair. Many times, hook-up attempts had to be aborted because of turbulence and wingtip vortices. In late 1953, an RF-84F flown by Convair test pilot Beryl Erickson was torn free from the B-36's wing. Although the RF-84F managed to land safely, the Convair team concluded that it was too dangerous to continue and decided to halt the program. A month later, the Air Force officially cancelled the TOM-TOM program. At this time, experiments with mid-air refueling techniques seemed to offer greater promise for increased fighter ranges with far less risk to the lives of aircrews. All three aircraft were de-modded and reverted to their original configurations.

Joe Baugher

Sources:

  1. United States Military Aircraft Since 1909, Gordon Swanborough and Peter M. Bowers, Smithsonian, 1989.
     
  2. Post-World War II Bombers, Marcelle Size Knaack, Office of Air Force History, 1988.
     
  3. General Dynamics Aircraft and their Predecessors, John Wegg, Naval Institute Press, 1990.
     
  4. American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday, 1982.
     
  5. Convair B-36: A Comprehensive History of America's "Big Stick", Meyers K. Jacobsen, Schiffer Military History, 1997

 

Project  'Tom-Tom"

 

The GRB-36F "FICON"

(FIghter CONveyor)

Click on Picture to enlarge

Click on Picture to enlarge

Convair GRB-36F "FICON"

During the early 1950s, the Air Force decided to conduct experiments on the feasibility of B-36's carrying fighter aircraft suspended under their bellies. This would not only provide the bomber with its own fighter protection, but would make it possible for the bomber to carry the fighter long distances to a combat zone. Upon reaching the edge of the enemy's territory, the fighter would be released to conduct reconnaissance or bombing missions on its own.

The YF-96A re-designated the YRF-84F "Ficon" (which is a contraction of "Fighter" and "Conveyer") was designed so that it could be carried by a B-36. As the FICON, it made its first flight on March 30, 1953. However, subsequent development of mid-air refueling for range extension of fighter aircraft proved so successful that experiments with parasite fighters were discontinued.

The single GRB-36F (or YRB-36F) was modified from RB-36F S/N 49-2707. This aircraft was the prototype for the fighter conveyor program. Ten additional aircraft were converted for use as fighter conveyors, but all were modified from RB-36Ds.

 
TYPE
GRB-36F
 
Number Built/Converted
1 (cv)
 
Remarks
RB-36F mod. to carry YRF-84F
 

SPECIFICATIONS
Span:
230 ft. 0 in.
Length: 162 ft. 1 in.
Height: 46 ft. 8 in.
Weight: 357,500 lbs. (max. gross weight)
Armament: Two 20mm cannons in the tail plus an air-launchable Republic YRF-84F.
Engines: Six Pratt & Whitney R-4360-53 radials of 3,800 hp. each (takeoff power) and four General Electric J47-GE-19 turbojets of 5,200 lbs. thrust each
Crew: 19

PERFORMANCE
Maximum speed:
Approximately 400 mph.
Cruising speed: Approximately 200 mph.
 

The Air Force Museum

The GRB-36F "FICON"

Project  "FICON"

 

The B-36G

 

Click on Picture to enlarge

The B-36G / YB-60

The YB-36G was designed as an all-jet version of the
B-36. Eight Pratt & Whitney XJ57-P-3 turbojet engines were mounted in four nacelles in an arrangement very similar to the Boeing B-52. The USAF authorized Convair to modify two B-36Fs (S/N 49-2676 & 49-2684) in early 1951. Although the -G was similar to the basic B-36, there was substantial reengineering done including a completely new swept wing. The design was eventually redesignated YB-60 to reflect these differences. The first flight was 18 April 1952 and performance was better than the B-36, but was greatly inferior to the Boeing XB-52. The YB-60 never entered production. The second prototype aircraft was never completely finished and both YB-60s were scrapped in the mid-1950s.

The YB-60 will be covered in greater detail later in the USAF Bomber Virtual Aircraft Gallery series.

 
TYPE
YB-36G
 
Number Built/Converted
0
 
Remarks
Two built as YB-60
 

Notes:

  • Serial numbers: (as YB-60) 49-2676 and 49-2684
  • The YB-60s were modified from unfinished B-36Fs on the Convair assembly line.
  •  

    Only 49-2676 flew before program cancellation. First flight was 18 April 1952.

    The Air Force Museum

     

    The B-36G / YB-60

     

     

    The B-36H

     

    The B-36H was an improved version of the B-36F. Eighty three -H models were built with 1950-52 serial numbers. Improvements incorporated into the aircraft included a second flight engineer station, relocation of the radar equipment inside the pressurized compartment to allow for in-flight troubleshooting and repair, and an improved AN/APG-41A tail turret defensive fire control radar system.

    The first flight of a B-36H was on 5 April 1952. By the mid-1950s, 64 -Hs were modified to Featherweight III specifications. The B-36H (III) was capable of flying 423 mph. at 47,000 feet and was the fastest operational B-36 model.

     
    TYPE
    B-36H
     
    Number Built/Converted
    83
     
    Remarks
    Improved B-36F
     

    SPECIFICATIONS
    Span:
    230 ft. 0 in.
    Length: 162 ft. 1 in.
    Height: 46 ft. 8 in.
    Weight: 357,500 lbs. (max. gross weight)
    Armament: Sixteen 20mm cannons in eight remotely controlled power turrets plus 86,000 lbs. of bombs. Featherweight III conversions had two 20mm cannons in the tail only.
    Engines: Six Pratt & Whitney R-4360-53 radials of 3,800 hp. each (takeoff power) and four General Electric J47-GE-19 turbojets of 5,200 lbs. thrust each
    Crew: 13 for Featherweight III; 15 otherwise

    PERFORMANCE
    Maximum speed:
    416 mph. at 44,000 (423 mph. at 47,000 for Featherweight III)
    Cruising speed: 235 mph.
    Range: 3,200 miles with 10,000 lb. bomb load (combat radius); 7,700 mile ferry range
    Service Ceiling: 44,000 ft. (47,000 for Featherweight III)


    The Air Force Museum

    B-36H

    Click on Picture to enlarge

    The B-36H had a rearranged crew compartment and additional twin tail radomes to store the components of the AN/APG-41-A radar. The AN/APG-41A was far superior to the AN/APG-32 gun laying radar employed by the preceding B-36Ds and B-36Fs.

    By this point in time, modifications to the B-36 were relatively minor with each subsequent upgrade. An attempt to convert the B-36H into a tanker was undertaken, but such models never entered service.

    The B-36H and B-36F prototypes were first flown at almost the same time (November 1950). Yet, B-36H deliveries did not start until December 1951, when the Air Force already had most of its 34 B-36Fs. The B-36H's marked improvement over the F accounted for the delay between production. The Air Force bought 156 B/RB 36Hs more than double the production total of any other B-36.

    Once underway the production flow of B/RB-36Hs was steady, averaging 8 aircraft per month during 1952, and 6 monthly between January and September 1953.

    By 1952, engineering on the B-36 was little more than correction of rather minor deficiencies showing up in service. The B-36H (like the B-36F) had 6 R 4360 53 engines, but the early troubles of these new engines were virtually under control. Other problems arose, however. During a few months in 1952, all B-36s were restricted to an altitude of 25,000 feet after an RB-36 accident at 33,000 feet was traced to a faulty bulkhead. This restriction remained in effect until all deficient bulkheads were discovered and replaced.

    The B-36's original propeller blades carried flight restrictions that hampered performance. A new blade, made by a special flash welding process, could be used freely except for landing and takeoff. This blade weighed an extra 20 pounds, but its greater efficiency promised to compensate for the loss in aircraft range. A batch of 1,175 was ordered for prompt installation.

    In March, defective landing gears caused a series of accidents. After 2 crashes, the Air Force grounded all B-36s except the first 152. This meant that almost all of the last half of B/RB-36F productions and some 30 B/RB-36Hs already accepted by the Air Force could not be flown. Investigations from the start had blamed the aircraft's landing gear pivot shaft. Since a heavier bar could be devised and serve until a permanent alteration could be made, the grounding orders were soon lifted.

    Some B-36Hs and B-36H reconnaissance versions were reconfigured by Convair in 1954. They were returned to SAC in the same year as B/RB-36H-111s, having undergone the same stripping and overall modification as other featherweight B/RB-36s. No troubles were met with during the fulfillment of the B/RB-36H or other featherweight modification contracts. The crew of each modified aircraft was cut. For high altitude operations, B-36s carried only a crew of 13 (a decrease of 2); RB-36s, a crew of 19 (a decrease of 3).

    A total of 83 B-36Hs were accepted. The Air Force accepted 32 B-36Hs in fiscal year 1952--7 in December 1951, 5 in January 1952, 3 in February, 5 in March, and 4 in each of the next 3 months. It received 43 B-3611s in FY 53-4 in July 1952, 4 in August, 7 in September, 3 in October, 4 in November, 2 in December, 4 in January 1953, and 3 during each of the next 5 months. The last 8 B-36Hs were accepted in FY 54- 3 in July 1953, 3 in August, and 2 in September.

    All B-36Hs, including the last one built, had been accepted by the end of September.

    In round figures, the B-36H and B-36F prices were alike. In reality, the B-36H cost an additional $11,321. Airframe costs were much lower, but the price of the engines showed a steep increase. Armament, electronics, and propeller cost also had gone up. The new costs were: airframe, $2,077,785; engines (installed), $874,526; propellers, $214,186; electronics, $80,272; ordnance, $30,241; armament, $872,436.

    RB-36H: The Air Force bought 73 long range reconnaissance versions of the B-36H. Twenty-three were accepted in FY 52 (all during the first 6 months of 1952); 42 others in FY 53 (between July 1952 and June 1953). The last 8 were delivered in FY 54. The RB-36H price matched that of the B-36H and did not include the featherweight modification costs of 1954.

    B-36H (Tanker) : Searching for a tanker that could refuel jet aircraft at higher altitudes and higher speeds, SAC in early 1952 became interested in a readily convertible B-36 bomber tanker. The Air Force therefore asked Convair to equip one B-36 with a probe and drogue refueling system. The modification contract was approved in February 1952 and the work was completed in May. Testing, postponed to the end of the month because of the late delivery of one B-47 receiver aircraft, was satisfactory enough. Yet, no other tests took place until January 1953, after a new and vastly improved British made probe and drogue refueling system was installed. The British had developed refueling techniques to the point where they were actually in use on commercial airplanes, and the Air Staff in late 1947 had already begun to consider adapting the British technique to combat aircraft refueling. This would allow short range but relatively speedy bombers of the B-50 type to get to a distant and heavily defended target with the atomic bomb-a task allocated to the B-36, but especially hazardous due to that long range bomber's slow speed.

    The converted B-36H tanker subsequently flown could refuel one or more receiver aircraft. The 9 crewmember tanker could be returned to its standard bomber configuration in some 12 hours. But the B-36's bomber commitments never really allowed SAC to exploit these features.

    Conversion of SAC's heavy bomb wings to B-52 aircraft began in June 1956, with the B-36H equipped 42d Wing at Luring AFB, Maine. The 93d Bomb Wing at Castle AFB, Calif., fully equipped with B-52s in April 1956, had been a B-47 outfit prior to conversion. Nonetheless, like the final B-30s, the much improved B-36Hs were among the last to go.

    A total of 83 B-36Hs were accepted, starting in 1952. Phaseout (replaced by B-52s) took place from 1956-1959.

    One B-36 was modified by Convair in 1952 to carry guided air missiles (GAMS), specifically the GAM 63 Rascal, under development by the Bell Aircraft Corporation since 1946. The name Rascal derived from the guidance system used during the missile's dive on the target. This system was called a Radar Scanning Link, and the word Rascal was formed by combining the underlined letters of the 3 words.

    A mockup inspection of the B-36/Rascal prototype disclosed no major obstacles, and 11 other B-365 were programmed to be modified as director aircraft (DB-36s) for the new missiles. Several factors soon dictated changes in USAF plans. The principal ones were ongoing Rascal difficulties, imposition of new technical requirements, and reorientation of the program to achieve the best aircraft/missile operational combination. Although testing with the DB-36 would go on for awhile, the Air Staff decided in mid 1955 that it definitely wanted the B-47, not the B-36, to carry the Bell rocket powered GAM 63. Time lessened the decision's importance when the Rascal program was canceled in November 1958. At a top speed of Mach 2.95, the Rascal could carry a 3,000 pound nuclear warhead 90 nautical miles. Still, it remained unreliable and was overtaken by technological progress. Most of the DB-36 modification contract was canceled. Convair completed only 3 aircraft and reimbursed $1.6 million to the Air Force.

    One B-36H (Serial No. 51 5712) never reached SAC. The Air Force reserved it for special tests that it hoped would lead to the design of the world's first atomic powered plane. The future nuclear propelled B-36 (temporarily labeled the X-6) did not materialize. Even so, the modified and redesignated B-36H (NB-36H) saw extensive duty as a nuclear reactor test bed. Forty-seven test flights were made, yielding valuable data on the effects of radiation upon airframe and components. The NB-36H had undergone various modifications prior to testing. The most important one added a crew compartment to the fuselage nose section. This shielded all crew members from radioactive rays, when the nuclear reactor in the aft bomb bay operated. Composed of lead and rubber, this compartment completely surrounded the crew. Only the pilot and copilot could see out through the foot thick, leaded glass windshield. A closed circuit television system enabled the crew to see the reactor as well as other parts of the aircraft.

    On 6 April 1955 a B-36 launched a guided missile with an atomic warhead from 42,000 feet. The explosion took place 6 miles above Yucca Flat, Nevada. It was the highest known altitude of any nuclear blast at the time.

    Global Security

     

     

    The RB-36H

     

    Click on Picture to enlarge

    The RB-36H was the strategic reconnaissance version of the B-36H. Seventy three aircraft were ordered by the USAF. The aircraft had performance similar to the RB-36F and incorporated most of the design improvements of the standard -H model. By the mid-1950s, the reconnaissance role was greatly reduced for the RB-36 aircraft, so these aircraft were used primarily as bombers. Only the first forward bomb bay was equipped with cameras. The other bays were used as conventional bomb bays.

    Ellworth AFB, South Dakota is named for Brigadier General Richard E. Ellsworth who was killed in the crash of an RB-36H (S/N 51-13721) on 18 March 1953 along with 22 others.

     

     
    TYPE
    RB-36H
     
    Number Built/Converted
    73
     
    Remarks
    Photo Recon. version of the B-36H

    SPECIFICATIONS
    Span:
    230 ft. 0 in.
    Length: 162 ft. 1 in.
    Height: 46 ft. 8 in.
    Weight: 357,500 lbs. (max. gross weight)
    Armament: Sixteen 20mm cannons in eight remotely controlled power turrets plus approximately 50,000 lbs. of bombs. Featherweight III conversions had two 20mm cannons in the tail only.
    Engines: Six Pratt & Whitney R-4360-53 radials of 3,800 hp. each (takeoff power) and four General Electric J47-GE-19 turbojets of 5,200 lbs. thrust each
    Crew: 19 for Featherweight III; 22 otherwise

    PERFORMANCE
    Maximum speed:
    Approximately 420 mph.
    Cruising speed: Approximately 225 mph.
    Range: Approximately 8,000 miles
    Service Ceiling: Approximately 50,000 ft. (maximum for reconnaissance missions)

    The Air Force Museum

     

    The B-36H was destined to be the major production version of the B-36, with a total of 83 B-36Hs being built. The B-36H was much the same as the B-36F which preceded it, but had a rearranged crew compartment. In addition, the B-36H featured a new AN/APG-41A radar system in the tail which aimed the two 20-mm cannon in the tail turret. The new AN/APG-41A radar installation featured additional twin tail radomes, and was far superior to the AN/APG-32 gun-laying radar employed by the preceding B-36Ds and B-36Fs. The new radar installation featured additional twin tail radomes. The engines were six R-4630-53 and four J47-GE-19, same as those of the B-36F.

    The B-36H was flown for the first time on April 5, 1952. The B-36H deliveries did not start until December of 1952, at which time the Air Force already had most of its 34 B-36Fs. A total of 83 B-36Hs were built. The USAF also bought 73 long-range reconnaissance versions of the B-36H under the designation RB-36H. 23 were accepted during the first six months of 1952, and the remainder were all delivered by September of 1953. The Air Force acquired a total of 156 B/RB-36Hs (83 B-36Hs, 73 RB-36Hs), the largest production run of any B-36 version.

    For a few months in 1952, all B-36s were restricted to altitudes below 25,000 feet after an RB-36 accident at 33,000 feet was traced to a faulty bulkhead. This restriction remained in place until all bulkheads could be inspected and defective units replaced.

    One B-36H was converted into a mid-air refueling tanker. The Air Force was interested in a tanker which could refuel jet aircraft at higher altitudes and higher speeds than those that could be reached by converted B-29 tankers. The modification contract was approved in February of 1952 and the work was completed in May. Testing with B-47 receiver aircraft took place at the end of May. No other tests took place until January of 1953, when a probe-and-drogue refueling system was installed. The 9-crew tanker could be converted back to its standard bomber configuration in only 12 hours. However, no other tanker conversions of the B-36 were carried out, since converted B-29s and B-50s, plus the new KC-97, were able to handle mid-air refueling much more economically.

    The B-36H-equipped 42nd wing at Loring AFB, Maine, began to convert to B-52s in June of 1956.
     

    Serials of B-36H/RB-36H:

    50-1083/1091		Convair B-36H-1-CF Peacemaker
    50-1092/1097		Convair B-36H-5-CF Peacemaker
    50-1103/1105		Convair RB-36H-1-CF Peacemaker
    50-1106/1110		Convair RB-36H-5-CF Peacemaker
    51-5699/5705		Convair B-36H-10-CF Peacemaker
    51-5706/5711		Convair B-36H-15-CF Peacemaker
    51-5712/5717		Convair B-36H-20-CF Peacemaker
    51-5718/5723		Convair B-36H-25-CF Peacemaker
    51-5724/5729		Convair B-36H-30-CF Peacemaker
    51-5730/5735		Convair B-36H-35-CF Peacemaker
    51-5736/5742		Convair B-36H-40-CF Peacemaker
    51-5743/5747		Convair RB-36H-10-CF Peacemaker
    51-5748/5753		Convair RB-36H-15-CF Peacemaker
    51-5754/5756		Convair RB-36H-20-CF Peacemaker
    51-13717/13719		Convair RB-36H-20-CF Peacemaker
    51-13720/13725		Convair RB-36H-25-CF Peacemaker
    51-13726/13731		Convair RB-36H-30-CF Peacemaker
    51-13732/13737		Convair RB-36H-35-CF Peacemaker
    51-13738/13741		Convair RB-36H-40-CF Peacemaker
    52-1343/1347		Convair B-36H-45-CF Peacemaker 
    52-1348/1353		Convair B-36H-50-CF Peacemaker
    52-1354/1359		Convair B-36H-55-CF Peacemaker
    52-1360/1366		Convair B-36H-60-CF Peacemaker
    52-1367/1373		Convair RB-36H-45-CF Peacemaker
    52-1374/1380		Convair RB-36H-50-CF Peacemaker
    52-1381/1386		Convair RB-36H-55-CF Peacemaker
    52-1387/1392		Convair RB-36H-60-CF Peacemaker
    

    Specification of Convair B-36H

    Engines: Six 3800 hp Pratt & Whitney R-4360-53 Wasp Major air cooled radial engines, plus four 5200 lb.s.t. General Electric J47-GE-19 turbojets. Performance: Maximum speed 439 mph at 31,120 feet, 416 mph at 36,700 feet. Cruising speed 234 mph. Stalling speed 123 mph. Initial climb rate 2060 feet per minute. Service ceiling 44,000 feet. Combat ceiling 40,800 feet. Combat radius 3113 miles with 10,000 pounds of bombs. 7691 miles ferry range. Weights: 168,487 pounds empty, 253,900 pounds combat, 370,000 pounds maximum. Dimensions: Wingspan 230 feet 0 inches, length 162 feet 1 inches, Height 46 feet 8 inches, wing area 4772 square feet. Armament: Two 20-mm M24A1 cannon each in six retractable remotely-controlled fuselage turrets, tail turret and nose mounting, with 9200 rounds of ammunition. Normal bomb load up to 72,000 pounds. Maximum bomb load 86,000 pounds

    Joe Baugher

    Sources:

    1. United States Military Aircraft Since 1909, Gordon Sqanborough and Peter M. Bowers, Smithsonian, 1989.

    2. Post-World War II Bombers, Marcelle Size Knaack, Office of Air Force History, 1988.

    3. General Dynamics Aircraft and their Predecessors, John Wegg, Naval Institute Press, 1990.

    4. American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday, 1982.

    5. Convair B-36: A Comprehensive History of America's "Big Stick", Meyers K. Jacobsen, Schiffer Military History, 1997.

     

     

    The NB-36H

    The Flying Nuclear Testbed

     

    The "Convair Crusader" NB-36H, 51-5712 was equipped with a functioning air-cooled nuclear reactor and a lead shielded crew compartment. The reactor did not power the airplane. Tests were conducted to determine the effects of radiation on instrumentation and equipment.

     

    Note: Information on this page comes from a Convair report detailing the development of the nose section of the aircraft from mock-up to installation.

     

    Click on Picture to enlarge

    Note the radiation warning symbol on the tail.

    The NB-36H (originally designated XB-36H) was used in the studies and testing of an airborne nuclear reactor. The reactor to be carried aloft was not to be used for aircraft propulsion but primarily for determining many unknown factors pertaining to the effects of nuclear reaction. The NB-36H, named The Crusader, flew 47 times during the mid-1950s.

    The XB-36H carried a crew of five: pilot, copilot, flight engineer, and two nuclear engineers. All crew members were located in the forward section of the aircraft while the atomic reactor was located aft. The greenhouse nose of a production B-36H was replaced by a more conventional cockpit arrangement. The new nose section was slightly shorter than the original and the nose landing gear was moved 6 inches forward to allow for a crew entrance/escape hatch just behind the nose landing gear.

     

    The NB-36H

     

     

    The B-36J

    Click on Picture to enlarge

    B-36J-75-CF S/N 52-2827, the last production B-36J.

    The B-36J was an improved version of the B-36H. Improvements included the addition of fuel cells in the outboard wing area and a strengthened landing gear. The landing gear supported a increase in gross weight to 410,000 pounds -- a 50,000 pound increase over the -H model.

    The B-36 remained in service with the Strategic Air Command throughout the 1950s; however, by late 1958 the B-36 was phased out and replaced by the Boeing B-52 as the premier USAF heavy bomber .

    The Air Force Museum's B-36J was flown to Wright Field from Davis-Monthan AFB, Arizona, on April 30, 1959. This was the last flight ever made by a B-36. It was also the first airplane to be placed inside the new Museum building.

     
    TYPE
    B-36J
     
    Number Built/Converted
    33
     
    Remarks
    Last production version

    SPECIFICATIONS
    Span:
    230 ft. 0 in.
    Length: 162 ft. 1 in.
    Height: 46 ft. 9 in.
    Weight: 410,000 lbs. (max. gross weight)
    Armament: Sixteen M24 20mm cannons in eight nose, tail and fuselage turrets; plus bombs--nuclear or 86,000 lbs. of conventional (Featherweight III aircraft had only 20mm cannons)
    Engines: Six Pratt & Whitney R-4360-53 radials of 3,800 hp. each (takeoff power) and four General Electric J47-GE-19 turbojets of 5,200 lbs. thrust each
    Crew: 13 after Featherweight III conversion; 15 otherwise

    PERFORMANCE
    Maximum speed:
    411 mph. [418 mph. for B-36J (III)] at combat weight
    Cruising speed: 230 mph
    Range: approximately 10,000 miles
    Service Ceiling: 43,600 ft. (at combat weight)

    The Air Force Museum
     

    B-36J

    Click on Picture to enlarge

    Loading aircraft image... Loading aircraft image...

    The limits of piston-engine technology were exemplified during takeoff. The B-36 suffered from long, lumbering takeoff runs and a low top speed. Convair addressed this problem, beginning with the B-36D model, by adding four auxiliary jet engines in pods under the outer wings to provide short-term boosts in power. B-36 crews thus referred to having "six [engines] turning and four [engines] burning". (Given the poor reliability of the engines, this was sometimes changed to, "two turning, two burning, two joking, and two smoking".) Most of the earlier aircraft were converted to B-36D specification. Later models featured increased piston engine power, improved radar, redesigned crew compartments, and (in the final B-36J model) extra fuel tanks to regain the range lost by the jet engines' greater thirst for fuel.

    Toward the end of B-36 production, heavy defensive armament was falling out of favor: the range of new air-to-air missiles made hand-aimed guns obsolete. The final fourteen B-36J aircraft were delivered as "featherweights", with all guns but the radar-aimed tail turret removed. The remotely operated power turrets of the original design were heavy, unreliable, and needed significant manpower; removing them allowed the aircraft to reach altitudes above 50,000 ft (15 km) and fly longer and further. Other B-36 aircraft were modified to this configuration, especially the reconnaissance aircraft, for which these attributes were especially advantageous. There were three Featherweight programs. Featherweight I removed most defensive hardware from line aircraft. Featherweight II continued the weight-reduction program by removing crew-comfort items such as the rear-compartment galley. Featherweight III aircraft were delivered from the factory without these items.

     

    The B-36J was the final production version of the B-36. It had two additional fuel tanks, one on the outer panel of each wing, which increased the fuel load by 2770 gallons, for a total fuel capacity of 36,396 gallons. It also had a much stronger landing gear, permitting a gross takeoff weight as high as 410,000 pounds.

    The YB-36J flew for the first time in July of 1953. The first production B-36J flew in September of 1953.

    The last 14 B-36Js were manufactured as B-36J(III) featherweights, with all guns removed except the pair of cannon at the tail position. The crew was reduced to 13, and the blisters were replaced by flat windows. The reduction in weight enabled a service ceiling of 47,000 feet to be reached, although some missions were flow as high as 50,000 feet. In contrast to the other B-36 featherweights (which were modified after delivery), these planes were modified on the production line during manufacture.

    A total of 33 B-36s were accepted, the last one (a III featherweight) being delivered on August 14, 1954.

    Serials of Convair B-36J:

    52-2210/2221	Convair B-36J-1-CF Peacemaker
    52-2222/2226	Convair B-36J-5-CF Peacemaker
    52-2812/2818	Convair B-36J-5-CF Peacemaker
    52-2819/2827	Convair B-36J-10-CF Peacemaker

    Specification of Convair B-36J Peacemaker:

    Engines: Six 3800 Pratt & Whitney R-4360-53 Wasp Major air cooled radial engines, plus four 5200 lb.s.t. General Electric J47-GE-19 turbojets. Performance: Maximum speed 411 mph at 36,400 feet. Cruising speed 203 mph. Initial climb rate 1920 feet per minute. Service ceiling 39,900 feet. Range 6800 miles with 10,000 pound bombload. Weights: 171,035 pounds empty, 266,100 pounds combat, 410,000 pounds maximum. Dimensions: Wingspan 230 feet 0 inches, length 162 feet 1 inches, Height 46 feet 8 inches, wing area 4772 square feet. Armament: Two 20-mm M24A1 cannon each in six retractable, remotely-controlled fuselage turrets, tail turret and nose mounting, with 9200 rounds of ammunition. Normal bomb load up to 72,000 pounds. Maximum bomb load 86,000 pounds

    Joe Baugher

    Sources:

    1. United States Military Aircraft Since 1909, Gordon Swanborough and Peter M. Bowers, Smithsonian, 1989.
       

    2. Post-World War II Bombers, Marcelle Size Knaack, Office of Air Force History, 1988.
       

    3. General Dynamics Aircraft and their Predecessors, John Wegg, Naval Institute Press, 1990.
       

    4. American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday, 1982.
       

    5. Convair B-36: A Comprehensive History of America's "Big Stick", Meyers K. Jacobsen, Schiffer Military History, 1997.

     

     

    The Convair YB-60

     

    The YB-60 was the all-jet competitor to the Boeing B-52 Stratofortress.

     

    Click on Picture to enlarge

    The second Convair YB-60 prototype, s/n 49-2684, minus its J-57-P-3 jet engines were never delivered by the Air Force.  

    The YB-36G was designed as an all-jet version of the B-36. Eight Pratt & Whitney XJ57-P-3 turbojet engines were mounted in four nacelles in an arrangement very similar to the Boeing B-52. The USAF authorized Convair to modify two B-36Fs (S/N 49-2676 and 49-2684) in early 1951. Although the G was similar to the basic B-36, there was substantial reengineering done including a completely new 37-degree swept wing. The design was eventually redesignated YB-60 to reflect these differences. The first flight was April 18, 1952, and performance was better than the B-36, but was greatly inferior to the Boeing XB-52. The YB-60 never entered production. The second prototype aircraft was never completely finished, and both YB-60s were scrapped in the mid-1950s.
     

    Type Number built/
    converted
    Remarks
    YB-60 2 (cv) Eight jet version of B-36


    Notes:
    ·
    Serial numbers: 49-2676 and 49-2684
    · The second YB-60 (S/N 49-2684) was never completed
    · First flight of the YB-60 was April 18, 1952

    SPECIFICATIONS:
    Span: 206 ft. 0 in.
    Length: 171 ft. 0 in.
    Height: 50 ft. 0 in.
    Weight: 300,000 lbs. maximum
    Armament: Designed for two 20mm cannons in the tail and up to 72,000 lbs. of bombs
    Engines: Eight Pratt & Whitney XJ57-P-3 turbojets of 8,700 lbs. thrust each
    Crew: Five (pilot, copilot, navigator, bombardier, tail gunner)

    PERFORMANCE:
    Maximum speed:
    approximately 510 mph
    Cruising speed: 435 mph
    Range: 10,000 miles maximum ferry range
    Service ceiling: 52,000 ft.

    The Convair YB-60

     

     

    The Convair XC-99 and Model 37

    The Air Force Museum June 2006

    XC-99 continues journey from Texas to museum

    Click on Picture to enlarge

    The only XC-99 ever built will eventually be displayed at the National Museum of the United States Air Force. Parts of the aircraft have been arriving at the museum from Texas since early 2004.

    For the past two years, the only XC- 99 ever built has been arriving at the museum, piece by piece.

    Disassembling of the aircraft began in January 2004, with parts being airlifted to the museum from the Kelly Annex of Lackland Air Force Base, Texas. In recent months, Worldwide Aircraft Recovery has removed the top cabin sections. This summer, the wings will be removed and delivered to the museum. The remaining fuselage sections will arrive at a later date.

    In 1942 the U.S. Army Air Forces wanted a long-range aircraft capable of carrying large numbers of troops or cargo. Consolidated Aircraft Corp. (later Convair) proposed adapting their XB-36 bomber, which was still under development, to fit the AAF’s requirements. The XB-36 made its first flight in August 1946, and the XC-99 made its first flight a year later on Nov. 24, 1947. Its first cargo run was into Kelly Air Force Base on July 14, 1950.

    The aircraft’s propellers were mounted on the trailing edge of the wings to reduce drag, thereby increasing the aircraft’s range. Neither the B-36 nor the XC-99 had in-flight refueling capabilities.

    During its service, the XC-99 logged more than 7,400 hours of flying time and moved more than 60 million pounds of cargo. The XC-99 made its final flight on March 19, 1957.

     

    The Convair XC-99 & Model 37

     

     

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    02/10/2014

     

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