Dedicated to all those who served with or supported the 456th Fighter Squadron or 456th Fighter Interceptor Squadron or the UNITED STATES AIR FORCE

 

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North American XB-45 / B-45 "Tornado"

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The development of the XB-45 was initiated in August 1944 in response to a spring 1944 request by the Army Air Force for proposals using the newly developed General Electric J35 axial-flow turbojet engine. The AAF issued requirements for a 500 mph top speed, a 1,000-mile combat radius and service ceiling of at least 40,000 feet. North American submitted its preliminary design studies in December and got approval for full-scale development in March 1945. Besides the North American XB-45, the Consolidated XB-46, Boeing XB-47 and Martin XB-48 resulted from the Army request.

The XB-45 was powered by four J35s arranged in pairs in wing-mounted nacelles. The Army considered jet bombers to be so fast that only the tail of the aircraft needed to be defended. The XB-45 carried only two .50-cal. machine guns in the tail. The power-assisted turret guns were fired manually by a tail gunner. The rest of the four man crew consisted of a pilot, copilot-radio operator and bombardier-navigator. The normal bomb load of the XB-45 was 8,000 lbs., but it was capable of carrying one 22,000 lb. "Grand Slam" bomb.

Three XB-45 prototypes were built and the first flight was March 17, 1947. The XB-45 competed against the four-engine XB-46 and proved superior. An initial production contract for 97 aircraft, built as B-45A, made the aircraft the first production all-jet bomber to enter service with the USAF.
 

Type

Number built/
converted

Remarks

XB-45

3

XB-45


Serial numbers: 45-59479 to 45-59481

SPECIFICATIONS:
Span: 89 ft. 6 in.
Length: 74 ft. 0 in.
Height: 25 ft. 2 in.
Weight: 66,820 lbs. (gross weight)
Armament: Two .50-cal. machine guns in the tail and 8,000 lbs. of bombs; note the aircraft could carry one 12,000-lb. "Tall Boy" or one 22,000-lb. "Grand Slam" bomb
Engines: Four Allison J35-A-11 turbojets of 4,000 lbs. thrust each
Crew: Four (pilot, copilot-radio operator, bombardier-navigator, tail gunner)

PERFORMANCE:
Maximum speed:
500 mph
Cruising speed: 419 mph
Range: 2,920 miles
Service ceiling: 38,500 ft.

 

 

 The XB-45 "Tornado"

Joe Baugher

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The North American B-45 Tornado was the first operational jet bomber to be used by the USAF. It was also the first jet aircraft to be refuelled in the air and was the first jet bomber to drop a nuclear weapon. For a couple of years during the early and mid-1950s, the B-45 Tornado was a key element in the US nuclear deterrent. Unfortunately, the B-45 was rather limited in its nuclear carrying capability, but proved to be a first-rate reconnaissance aircraft. Nevertheless, the Tornado was rapidly eclipsed in performance and capability by more advanced designs such as the Boeing B-47 Stratojet, and its service with the USAF was relatively brief.

The B-45 officially originated back in 1944, at a time when the USAAF was already aware of German advances in the field of jet propulsion, especially as applied to the development of jet bombers. Alarmed by German developments, the War Department called for bids from the aviation industry on a new family of jet-powered bombers, with gross weights ranging from 80,000 pounds to more than 200,000 pounds. These new aircraft were to be powered either by TG-180 or TG-190 engines which were then under development at General Electric. The TG-180 was eventually built by the Allison Division of General Motors as the J35, and the TG-190 was built by the General Electric company as the J47.

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In 1944, North American Aviation of Inglewood, California submitted a design known under the company designation NA-130 as its proposal in response to the War Department request. The NA-130 was a shoulder-wing monoplane of fairly conventional layout with a dihedral tailplane and a retractable landing gear. The Model 130 was to be powered by four turbojets, grouped in horizontal pairs, one pair under the wings on each side of the fuselage outboard of the tailplane.

A Letter Contract dated September 8, 1944 called for the development of three experimental aircraft based on the NA-130. The designation XB-45 was assigned. At the same time, three other contractors were also awarded development contracts, Convair for the XB-46, Boeing for the XB-47, and Martin for the XB-48.

The end of the Second World War resulted in the cancellation of many projects and the delay of others. However, the War Department felt that the development of a jet-powered bomber should still be pressed forward with the utmost speed, and the XB-45, XB-46, XB-47, and XB-48 contracts were left untouched. In 1946, rising tensions with its erstwile Soviet ally caused the USAAF to assign a high priority to the development of a jet-powered bomber. In response to this new sense of urgency, the USAAF decided to forego the competition that would ordinarily be held between the four entries and opted instead to review the available designs to see which of the contestants could be produced first.

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By mid-1946, the XB-45 and XB-46 were nearing completion, but the XB-47 and XB-48 were still at least two more years away. Since the USAAF was guided by what it felt to be a sense of great urgency, it decided to appraise the XB-45 and XB-46 right away and choose one of them for immediate production. Any consideration of the XB-47 and XB-48 would be deferred until after they had flown. if either the XB-47 or XB-48 turned out to be markedly superior to the plane that was then being produced, then that aircraft would be purchased and the currently-produced version would be phased out. This is indeed what happened when the XB-47 appeared.

The USAAF concluded that the Convair XB-46 would likely be inferior in performance to the XB-45, and that its thin, graceful fuselage would not be able to hold all the required radar equipment. Since the configuration of the XB-45 did not depart significantly from that of proven aircraft already in service and hence presented fewer risks, on August 2, 1946, the USAAF announced that they were going to endorse the immediate production of the B-45. A contract for 96 B-45As (North American N-147) was signed on January 20, 1947.

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The XB-45 was a shoulder-winged monoplane powered by four Allison-built General Electric J35-A-4 turbojets paired side-by-side in large nacelles underneath each wing. The tailplane had a large dihedral angle in order to clear the jet exhaust. The crew consisted of two pilots sitting in tandem underneath a transparent canopy, a bombardier in a transparent nose, and a gunner sitting in the extreme tail. The three forward crew members entered the aircraft by means of a large door on the left hand side of the nose, with the tail gunner having his own door in the right fuselage underneath the tailplane. The main landing gear was mounted just inboard of the engine nacelles, and retracted inward into wells in the wing roots.

The first XB-45 took off on its maiden flight on March 17, 1947 from Muroc Army Air Field, piloted by George Krebs. On that first flight, the aircraft had to be flown under severe speed restrictions, since the landing gear doors would not close properly. It was the first American four-jet bomber to fly.

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Three XB-45s were built. Each of the three XB-45s was instrumented for a different specialized phase of the program. Near the beginning of the test flight program, one of the XB-45s crashed, killing two of North American's test pilots. A total of 131 flights were carried out by the surviving two aircraft before they were turned over to the USAF.

The USAF accepted one of the XB-45s on July 30, 1948, the other on August 31. Initially, they did not have cabin pressurization, but this was later added. In June of 1949, one of the XB-45s was damaged beyond repair in an accident. The remaining XB-45 had only a limited testing value due to an initial shortage in government-furnished equipment. A USAF flight test crew delivered the plane to the Wright- Patterson AFB in Ohio, where equipment was installed for bombing tests at Muroc AFB in California, but very few tests were actually carried out because of excessive maintenance requirements. On May 15, 1950 the aircraft was transferred to the Air Training Command to serve as a ground trainer.

 

Serials of XB-45 Tornado:  45-59479/59481 North American XB-45 Tornado


Specification of North American XB-45 Tornado:

Engines: Four Allison J35-A-7 turbojets, rated at 4000 lb.s.t. each. Performance: Maximum speed 483 mph at 30,000 feet, 516 mph at 14,000 feet, 494 mph at sea level. Service ceiling 37,600 fet. Initial climb rate 2070 feet per minute. An altitude of 30,000 feet could be attained in 19 minutes. 2236 miles range with 8350 pounds of bombs, 1700 miles range with 14,000 pounds of bombs. Maximum range 2921 miles. Weights: 41,876 pounds, 66,820 pounds gross, 82,600 pounds maximum. Dimensions: Wingspan 89 feet 6 inches, length 74 feet 0 inches, height 25 feet 2 inches, wing area 1175 square feet.

Joe Baugher

Sources:

  1. American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday, 1982.
     
  2. Post World War II Bombers, Marcelle Size Knaack, Office of Air Force History, 1988.
     
  3. United States Military Aircraft Since 1909, Gordon Swanborough and Peter M. Bowers, Smithsonian, 1989.

 

 

The B-45 "Tornado"

Global Security

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B-45 Tornado

In 1943, aware of Nazi Germany's advances in the field of jet propulsion, the Army Air Forces (AAF) asked the General Electric Company to devise a more powerful engine than its prospective axial turboprop. This was a tall order, but it eventually brought about the production of the J35 and J47 turbojets. In 1944, 1 year after the jet engine requirements were established, the War Department requested the aircraft industry to submit proposals for various jet bombers, with gross weights ranging from 80,000 to more than 200,000 pounds. This was another challenge, and only 4 contractors answered the call.

Pressed for time, the AAF in 1946 decided to skip the usual contractor competition, review the designs, and choose among the proposed aircraft that could be obtained first. The multi jet engine B-45, larger and more conventional than its immediate competitor, won the round, with the understanding that if a less readily available bomber was to prove superior enough to supplant it (which the Boeing XB-47 did), that aircraft would also be purchased.

Testing of the XB-45 prompted pre-production changes. North American Aviation, Incorporated, redesigned the nose panel, increased the aircraft's stabilizer area, and lengthened the tailplane by nearly 7 feet. In August 1948, 22 of the 90 B-45s, ordered less than 2 years before, reached the newly independent Air Force. However, the B-45's increased weight, excessive takeoff distance, and numerous structural and mechanical defects generated scant enthusiasm.

With a first-flight date of March 17, 1947, the North American B-45 Tornado was the first jet-powered bomber to be put into production in the United States and the first to enter operational service with the USAF. The more capable B-45C model differed from earlier models of the B-45 in several respects; the most obvious difference in the appearance of the C model was the 1200-gallon fuel tank mounted at each wingtip.

Meanwhile, the B-47's future production had become certain, and in mid 1948 the Air Staff actually began to question the B-45's intrinsic value as well as its potential use. Soon afterwards, as President Truman's budgetary axe slashed Air Force expenditures, the programmed production of B-45s was reduced to a grand total of 142, a decrease of 51 aircraft.

Although continuously plagued by engine problems, component malfunctions, lack of spare parts, and numerous minor flaws, the B-45 regained importance. Like all bombers produced after the end of World War 11, the B-45 was designed to carry both conventional and atomic bombs. In mid 1950, when US. military commitments to the Korean War reemphasized the vulnerability of the North Atlantic Treaty Organization forces in Europe to Soviet attack, the Air Force made an important decision. Since the US. planned to produce large quantities of small atomic and thermonuclear weapons in the near future, the use of such weapons, heretofore a prerogative of the strategic forces, would be expanded to the tactical forces, particularly in Europe.

The program that ensued, under the code name of Backbreaker, entailed difficult aircraft modifications because several distinct atomic bomb types were involved and large amounts of new electronics support equipment had to be fitted in place of the standard components. In addition, the 40 B-45s allocated to the Backbreaker program also had to be equipped with a new defensive system and extra fuel tanks. Despite the magnitude of the modification project, plus recurring engine problems, atomic capable B-45s began reaching the United Kingdom in May 1952, and deployment of the 40 aircraft was completed in mid June, barely 30 days behind the Air Staff deadline.

The configuration of the B-45 is reminiscent of a World War II bomber equipped with jet engines instead of propellers driven by reciprocating power plants. The unswept wing had an average airfoil thickness ratio of about 14 percent and was equipped with trailing-edge single-slotted flaps for lift augmentation in landing and takeoff. Lateral control was accomplished with the use of conventional ailerons.

All control surfaces were hydraulically boosted, and an electrically actuated tab on the elevator was used to maintain longitudinal trim. The aerodynamic power of the trim-tab-elevator combination was so great that, in the event of an inadvertent maximum tab deflection, the pilot's strength was insufficient to overcome the resulting large elevator hinge moments if the hydraulic boost system failed or was turned off. Total in-flight destruction of at least one B-45, the aircraft operated by NACA, was probably caused by this combination of circumstances that resulted in a normal load factor far greater than the design value. The technology of power-assisted controls was in its infancy at the time of development of the B-45, and much was yet to be learned about the effective and safe application of such control techniques.

In performing the landing maneuver, pilots found that speed and flight-path angle during the approach as well as touchdown point on the runway were difficult to control with precision because of the absence of speed brakes or some other means of increasing the drag of the aircraft. As a result of the low drag, only a small amount of engine thrust was required in the approach configuration. In this low thrust range, changes in thrust with throttle movement required a relatively long period of time and rendered control of flight path and speed difficult. At higher thrust levels, changes in thrust with time were more rapid. Hence, higher aircraft drag and consequently higher required thrust would have been desirable in the approach and landing configurations. Somewhat similar problems with speed control were experienced with the Messerschmitt Me 262, the first jet fighter to enter operational service. Again, experience taught important lessons applicable to the design of later jet-powered bomber aircraft.

Manned by a crew of four, the B-45 had two pilots seated in tandem under a transparent canopy, a bombardier located in the nose, and a tail gunner. Only the pilots were equipped with ejection seats. In an emergency, the bombardier, located in the nose of the aircraft, was expected to evacuate through a hatch located in the side of the fuselage. To minimize the hazards associated with the high-velocity airstream, a fuselage flap was deployed ahead of the hatch to deflect the airstream away from the exiting bombardier. An escape hatch with deflector flaps was also provided for the tail gunner. Environmental control for the crew included pressurization, heating, and cooling.

With a gross weight of 110, 050 pounds, the B-45 was in the same weight class as the wartime Boeing B-29 but had a maximum speed advantage over the B-29 of more than 200 miles per hour. A 10 000-pound weapon load could be delivered by the B-45 at a mission radius of 1008 miles. Ferry range of the aircraft was 2426 miles. The maximum lift-drag ratio of the B-45 was 16.3, about the same as that of the B-29, and its zero-lift drag coefficient was a much lower 0.0160 as compared with 0.0241 for the earlier aircraft.

The Tornado first entered service with the Strategic Air Command in November 1948, and final retirement of the type from operational service took place in 1958. The Air Force accepted a total of 142 B-45s in various configurations, 51 aircraft fewer than originally ordered. The B-45 program included 3 experimental XB-45s aircraft (one of which was completed as a preproduction example), 96 production B-45As (some of which were designated as B-45A-5s reflecting in-production improvements), 10 B-45Cs , and 33 RB-45Cs. The aircraft were produced by North American Aviation, Incorporated, of Inglewood, California, with most of the aircraft being built in a former Douglas facility at Long Beach, California.

The B-45 served well as a reconnaissance aircraft during the Korean war. The reconnaissance models were designated RB-45Cs and assigned to the Strategic Air Command. The Tornado performed classified, deep penetration photographic intelligence missions over many cold war communist countries. The reconnaissance version of the B-45 became the forerunner of the U-2 and SR-71 surveillance aircraft.

All told, and in spite of its many valuable secondary functions, the B-45 did not achieve great glory. The entire contingent, Backbreaker and reconnaissance models included, was phased out by 1959. Yet, the B-45 retained a place in aviation history as the Air Force's first jet bomber and as the first atomic carrier of the tactical forces.

 

Development

 

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Like the trouble plagued but eventually successful and long lasting B-47, the B-45 officially originated in 1944, when the War Department called for bids and proposals on an entire family of jet bombers, with gross weights ranging from 80,000 to more than 200,000 pounds. These were ambitious requirements considering the kind of airplanes being planned at the time in the United States and elsewhere. Yet, the emergence of unrealistic requirements was a common practice that would endure for decades. From experience, government officials most likely rationalized that inflating the requirements was the only way to get at least the minimum acceptable. Late in 1948, engineers of the Air Materiel Command began to point out the pitfalls of this practice. But their concern did not prevail. In 1952, many in the Air Staff also recommended caution and their efforts achieved some degree of success. Nevertheless, as the "weapon system concept" gained momentum, it became evident that the Air Force believed increasingly that mission objectives had to come first and that technology could be made to satisfy such objectives.

Unofficially, the roots of both the B-45 and B-47 aircraft could be traced to 1943, when the Army Air Forces, aware of Nazi Germany's advances in the field of jet propulsion, asked the General Electric Company to design something better than the TG-100 axial flow turboprop engine that was being developed for the Consolidated Vultee's 2 experimental P-81 escort fighters (the mass production of which did not materialize). The AAF's demands were met with General Electric's development of the 4,000 pound thrust TG-180 and the TG-190 engines, of which various models were to power subsequent bomber and fighter aircraft (The TG-180, eventually built in large quantities by the Allison Division of the General Motors Corporation, became the J35; the TG 190, continuously produced by the General Electric Company, became the J47).

For its part, North American began to attempt satisfying the AAF's requirements for a jet bomber with a design for an easy to build airframe, conventional in concept and straightforward in its aerodynamic form. Model 130, as the design was labelled in early 1944, was a mid-wing monoplane with dihedral tailplane and a retractable landing gear. North American planned to propel its new bomber with 4 jet units, grouped in horizontal pairs, 1 pair on each side of the fuselage outboard of the tailplane.

The AAF initiated the procurement of the future B-45 with Letter Contract AC-5126. This document, issued on 8 September 1944, called for the development and testing of 3 experimental B-45s, all of which were to be based on North American design 130. In time, as production of the aircraft appeared probable, North American altered the overall configuration of 1 of its 3 XB-45s. The selected vehicle was actually completed as a tactical model and, although seldom referred to as YB-45, assumed the role of a standard prototype.

The AAF originally intended to schedule a formal competition between the various contractors working on projects to satisfy the War Department's requirements of 1944. In 1946, since the early production of a jet bomber seemed highly desirable, the AAF decided to forgo the planned competition. Instead, available designs would be reviewed to determine which model could be obtained first. Four contractors were involved: North American, working on the XB-45; the Boeing Airplane Company, engrossed in the development of the swept wing, 6 jet XB-47; the Consolidated Vultee Aircraft Corporation (Convair), engaged in the XB-46; and the Glenn L. Martin Company, builder of the XB-48. The military characteristics, issued by the AAF on 17 November 1944 and embodied by the 4 projects, were specific but not restrictive. The B-45 and B-47 aircraft, the only 2 programs that went beyond the experimental stage, stemmed from the same requirements but ended having very little in common. Both were ordered as "medium" bombers, but in contrast to the B-47, which retained its medium bomber designation, the B-45 became a light bomber. The fact that the B-45, weighing 47,000 pounds and having a combat radius of 764 nautical miles, was finally listed as "light" also showed how swiftly concepts changed. Five years before, the World War 11 B-17G Flying Fortress, which weighed 37,672 pounds and had a combat radius of 873 nautical miles, was considered "heavy."

But while the XB-45 and XB-46 were nearing completion and flights of these aircraft were scheduled for 1947, the XB-47 and XB-48 in 1946 were still in the early stages of development, and 2 years might elapse before the end of their fabrication and initial flight testing. Pressed for time, the AAF opted to appraise the XB-45 and XB-46 immediately and to postpone consideration of the XB-47 and XB-48 until they flew. Then, if either the XB-47 or the XB-48 proved superior enough to supplant the new bomber being produced (which the XB-47 did) that aircraft would be bought. The AAF anticipated that the B-47's performance characteristics would exceed those of the B-45, but realistically believed that the swept wing, underslung engine nacelles, bicycle type landing gear, and other experimental features of the Boeing design would require an extended period of development. The XB-48, although more conventional than the XB-47, featured a 3 engine installation in each wing and would incorporate the bicycle type landing gear of the B-47. The XB-48 might prove to be superior to the XB-45, but any potential production of the Martin design remained several years away.

On 2 August 1946, the AAF endorsed the immediate production of the B-45. The decision did not specifically spell the end of the XB-46, but it was a poor omen. Already reduced to only 1 plane, the experimental B-46 program actually lingered until August 1947, when the AAF terminated the whole venture. Several factors accounted for the selection. First, the AAF concluded that the XB-46's projected performance most likely would be inferior to that of the XB-45. Second, the XB-46's fuselage was not configured to hold all required radar equipment. Finally, since the XB-45's design only departed slightly from proven configurations, it was the most logical choice prior to testing of the experimental model. The AAF's decision of 2 August prompted within 1 week the negotiation and signature of Contract AC-15569, which called for an initial lot of 96 B-45As (North American Model N-147), plus a flying static test version of the experimental type (NA Model N-130). The cost of the contract was $73.9 million.

On 17 March 1947, the first of the 3 experimental B-45s made its initial flight. The 1 hour flight, from Muroc Army Airfield, California, was conducted under stringent speed restrictions because the aircraft's landing gear doors did not close properly when the landing gear was retracted. This problem could have been avoided by installing new and available landing gear uplocks, but this time consuming installation was postponed. (As soon as World War II ended, most manufacturers had to compete fiercely for the few, limited orders. This was reason enough for North American not to delay the XB-45's flight). Nevertheless, the XB-45's demonstration was impressive. No large multi-engine jet bomber had ever been flown before (Douglas's experimental twin jet B-43, an outgrowth of the company's XB-42 Mixmaster, flew almost 1 year before the XB-45, but the XB-43 was very small and the 2 could not be compared. In the same vein, 2 German developments appearing in 1944 presented no true challenge. One of them, the Arado Ar-234, introduced by the Luftwaffe as a jet bomber, was so tiny that it rightly belonged to the fighter category. The Junkers Ju-287 only flew as a prototype designed to test a radical wing, Germany's nearing collapse presumably preventing completion of the aircraft). And, of primary importance from the manufacturer's standpoint, even though a B-45 production order had already been secured, the XB-45 flight preceded that of the still potentially competitive XB-46.

The Air Materiel Command planned an extensive test program for the 3 experimental airplanes developed by North American; each of the 3 was to be instrumented for a specialized phase of the program (In the late fifties, the various testing phases to which all aircraft were submitted were supplanted by testing categories. However, the changes affected the testing program's terminology more than its scope). The testing, however, was marred at the start by an accident that killed 2 of North American's crack test pilots and destroyed their aircraft. This accident was attributed to an engine explosion, but other contributing factors later came to light. These accounted for most of the changes specified in the B-45's production articles. Meanwhile, flight testing of the remaining XB-45s went on. Air Force pilots did not participate extensively in the initial tests. They flew only about 19 hours, while the contractor logged more than 165 flight hours on the 2 surviving aircraft. This total was accumulated in 131 flights, conducted before the Air Force took delivery of the planes. The Air Force accepted 1 XB-45 on 30 July 1948; the other, on 31 August. The acceptances were conditional because the pressurization systems of both planes did not function.

After North American fixed the pressurization of the XB-45 cabins, additional tests were undertaken. Air Force pilots flew a total of 181 hours in 1 XB-45 between August 1948 and June 1949, when an accident damaged the aircraft beyond economical repair. The remaining XB-45, although constructed to serve as a prototype, had limited testing value due to an initial shortage of government furnished equipment. Still, the Air Force put another 82 hours of flying time on the plane. A USAF flight test crew delivered the airplane to Wright Patterson AFB, Ohio, where equipment was installed for bombing tests at Muroc AFB, California. Unfortunately, the YB-45 proved to be an unsatisfactory test vehicle because it required excessive maintenance. Only 1 mission was accomplished between 3 August and 18 November 1949, and that mission was to evaluate the long awaited components. The airplane was used for high speed parachute drops after November 1949, but on 15 May 1950, it was transferred to the Air Training Command to serve as a ground trainer.

As might be expected, the crash of an XB-45 precipitated a thorough investigation. As suspected, special wind tunnel tests confirmed that the aircraft's insufficient stabilizing area had contributed directly to the accident. The lack of ejection seats, moreover, had practically eliminated the pilot and co pilot's chances for survival. As a result, 2 ejection seats were installed in the other experimental planes, while an advanced ejection system was being devised for the forthcoming production aircraft. In addition, future B-45s would be equipped with wind deflectors, placed in front of the escape doors from which the other 2 crew members (bombardier-navigator and tail gunner) would have to bail out in case of an emergency. North American also altered the structural configuration of the production vehicle. Most noticeable was a redesign of the nose panel. Finally, the aircraft's stabilizer area was increased, and the tailplane was lengthened from 36 to almost 43 feet.

 

Development Problems

 

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From the start, the introduction of the B-45 was hindered by a misunderstanding about the number of USAF pilots who were to be "checked out" in the aircraft at Muroc AFB by personnel of North American Aviation. In June 1948, delays in production made matters worse for the 47th Bombardment Wing, which was earmarked as first recipient of the new multi jet bombers. Late in the year, the pioneer wing's training problems were aggravated by shortages of several months' standing in ground handling equipment and special maintenance tools. Structural or mechanical defects in a number of the few available B-45s did not help.

Although available records do not disclose any serious consideration of canceling the entire B-45 production, the program apparently ran into trouble even before any of the aircraft became truly operational. Some B-45 records were destroyed; others provided a surprising amount of conflicting information. Throughout the years, Air Force historians in attempting to answer certain B-45 queries could only point out that early systems were acquired in many different ways and that variances in methods of documentation complicated matters. For instance, the date on which the B-45 reached an initial operational capability (IOC) could not be ascertained. Other historical data such as the B-45's first production delivery, total USAF testing hours, and the identification of the XB-45 initially destroyed, remained unclear. North American Aviation provided its testing hour total, but the figures did not agree with those obtained from Air Force sources. The most striking examples of the inadequacy of old records undoubtedly pertained to test data-not only on the B-45 bomber, but on other early aircraft as well. This was understandable to some degree because Air Force tests were accomplished at numerous bases and for a great variety of purposes. In any case, all dates and information supplied on the B-45 are based upon documentary evidence. Bits and pieces included in the B-45 coverage are provided in the belief that they may be significant to users.

As early as June 1948, at a meeting held in the office of General Hoyt S. Vandenberg, Air Force Chief of Staff since 30 April, doubts were expressed as to the B-45's value and its future utilization. It was decided (a decision evidently later rescinded) that no contract beyond the current one would be let, that production would go on as planned up to the 119th article, and that the funds already made available for a new contract would be used for another purpose. Obviously, the quantity of B-45s first ordered had been increased, but the contract amendment's date as well as other details are no longer known. A second contract (AC-18000) had been issued in February 1947, either on the 7th or 17th day of that month. This contract dealt with another version of the B-45, but the information also is sketchy. Reportedly, a third contract (W33-038-AC-21702) came into being in June 1948, when the Air Force as a whole showed scant enthusiasm for the aircraft, only to be canceled on an unknown later date.

One group would be equipped with the operational type, the initial 90 aircraft; the remaining aircraft would be placed in storage to cover the group's eventual losses. At the time, officials of the Tactical Air Command (TAC) were asked whether or not they liked the Northrop B-49 prototype, which had an empty weight of 88,000 pounds, almost twice that of the B-45. Shortly afterward, Gen. Muir S. Fairchild, USAF Vice Chief of Staff since 27 May, asked the Aircraft and Weapons Board to determine if the weight of the various types of aircraft earmarked for or already in production could be reduced. (The Aircraft and Weapons Board was established in August 1947. It made recommendations on problems submitted by the Air Staff and the commands. Composed of the Deputy Chiefs of Staff and major air commanders, the board proved too cumbersome and in December 1948 was replaced by the USAF Board of Senior Officers which included the Vice Chief of Staff, Deputy Chief of Staff for Operations, Deputy Chief of Staff for Materiel, and the Commanding General, Air Materiel Command. The dormant Aircraft and Weapons Board was discontinued in the fall of 1949. However, the establishment of the Air Council in April 1951 was accompanied by the formation of 4 additional boards: the Force Estimates Board; Budget Advisory Board; Military Construction Board; and a new USAF Aircraft and Weapons Board which replaced the Senior Officers Board. The reactivated Aircraft and Weapons Board lasted for over a decade.

Several conferences ensued, special attention being devoted to the B-45, with some board members suggesting that elimination of the co pilot position, of the AB/ARC 18 liaison set installed in that position, and of the B-45's tail bumper would take 700 pounds off the aircraft's empty weight. There were other suggestions, some of them equally haphazard. Col. William W. Momyer, who represented TAC at these conferences, discovered that the Air Staff labored under the false impression that TAC did not consider the B-45 suitable for bombardment operations, a conclusion probably based upon previous studies by the command on the aircraft's excessive take off distances. (Twenty years later, immediately after serving in Southeast Asia as Deputy Commander for Air Operations, Military Assistance Command, Vietnam, and simultaneously as Commander, Seventh Air Force, General Momyer, now a full general, assumed command of Tactical Air Command.)

In the early fall of 1948, by which time 190 B-45s were tentatively scheduled for production, the program's future still remained uncertain. Headquarters USAF wanted to know if TAC needed a reconnaissance aircraft, and if so would a reconfigured B-45 be satisfactory? If this should be the case, all B-45s would be converted to the reconnaissance role. TAC's answers came promptly. Indeed the command needed a new reconnaissance aircraft, but a reconnaissance version of the B-45 would not fulfill its requirements. TAC believed the Air Force would accrue more benefits by equipping 2 groups with the B-45 in order to determine the tactics and limitations of jet bombers. The merits of TAC's recommendations became academic, as budgetary restrictions and other unexpected developments altered all planning.

The budgetary axe that slashed the fiscal year 1949 defense expenditures did not leave the B-45 program unscathed. According to plans, 5 light bomb groups and 3 light tactical reconnaissance squadrons were included in the Air Force's goal of 70 groups. The reduced Air Force program dictated by continued financial restrictions and, more specifically, by President Truman's budget for fiscal year 1950 brought into focus the Air Force's dilemma. The shrunken B-45 program called for only 1 light bomb group and 1 night tactical reconnaissance squadron, which meant that the procurement of the aircraft had to be scaled down or that a substantial number of the aircraft would have to be placed in storage upon acceptance from the factory. Neither solution was attractive, but the Aircraft and Weapons Board quickly decided to cancel 51 of the 190 aircraft on order. Over $100 million would be released for crucial programs, and sufficient B-45s would be left to equip 1 light bomb group, 1 tactical reconnaissance squadron, plus a much needed high speed tow target squadron. Moreover, there would still be extra B-45s to take care of attrition throughout the aircraft's first line life. The first line life of an aircraft cannot be predetermined, only predicted. As a rule, an aircraft remains "first line" as long as it is "operational;' "modern;' and "capable of being used to perform critical and essential Air Force missions." Conversely, an aircraft becomes "second line,' when its limitations for combat or other military use have been formally recognized. However, second line aircraft may be called for first line duty under certain circumstances in emergency, and in services for which first line aircraft are not available.

Five light bomb groups were included in the 70 group force planned by the Air Force. In reprogramming available forces to meet the 48-group composition and deployment imposed by current funding limitations, only 1 light bomb group was authorized. This group, the Air Force tentatively decided, would be allocated to the Far East Air Forces (FEAF) and would be equipped with B-45s. Specifically, the Air Force intended to inactivate Barksdale's 47th Group and to replace the B-26s of FEAF's 3d Light Bomb Group, at Yokota Air Base in Japan, with the B-45s of the defunct group. Maintenance personnel of the 47th also would be transferred to Yokota so that FEAF would benefit from the B-45 "know how" gained by the aircraft's first recipient. But even logical and simple plans could go astray. Available and in coming B-45s could not carry sufficient fuel to fly to Hawaii, and equipping the aircraft with additional fuel tanks, a probable feature of future B-45 models, was at the time impossible. B-45A-1s, equipped with J35 engines, had a ferry range of 2,120 miles and a take off weight of 86,341 pounds that included 5,800 gallons of internal fuel. Almost half of the fuel was contained in two 1,200 gallon bomb bay tanks and no additional fuel space was available. Incoming B-45-5s, equipped with J47 engines, had a similar take off weight and a negligible range increase of 30 nautical miles. Obviously General Fairchild's interest in weight reduction retained its validity, but there were no simple solutions. Ferry ranges were computed on the basis that the aircraft's wing tip tanks and bomb bay tanks were retained when empty. If an increase of the weight figure was desired by a using agency, a reliable rule of thumb up to 1,000 pounds, Air Materiel Command engineers pointed out, was that every extra pound of weight induced a range decrease of 0.025 nautical miles. A corresponding small increase in range could be achieved by weight reduction.

Of course, it might have been practical to move the B-45s to Japan by sea. If a minimum of 10 feet could have been removed from each of the aircraft's wings, a rather impractical expedient, 3 B-45s could be deck loaded on a Liberty or Victory ship, for a transport fee of approximately $4,000 per aircraft. The use of other sea transports might also have proved possible, but further investigation came to a halt. Early in 1949, the Deputy Chief of Staff for Materiel stated that the overseas deployment of B-45s was out of the question for the time being as well as the immediate future. To begin with, the B-45s were not truly operational. They had no fire control or bombing equipment, and a suitable bomb sight was yet to be developed for the aircraft. Structural weaknesses, such as cracked forgings, had been uncovered in some of the few B-45s already available. And until corrected, such deficiencies certainly precluded any deployment abroad. Still another impediment arose. As reported by Air Materiel Command (AMC), the new J47 engine due to equip most of the B-45s suffered from serious problems. The engine had to be inspected thoroughly after 7 1/2 hours of flying time; if found still serviceable, it could only be flown an additional 7 1/2 hours before requiring a complete overhaul. Lack of money prevented the purchase of sufficient spare engines to ensure that, if deployed overseas, the B-45s could be kept flying. AMC anticipated difficulties, even for those aircraft that remained in the U.S., not far from the depots where the engines had to be inspected and overhauled. By mid year, the home based B-45s were expected to need 900 spare engines, none of which would be available. The shortage was compounded by the fact that F-86 requirements for J47s had first priority. The 1 engine F-86 Sabres, also produced by North American, began entering operational service in 1949, but did not go overseas before December 1950. Little relief could be expected, AMC concluded, until jet engines could be used for almost 100 hours between overhauls. At best, this meant that no jet aircraft could be stationed out of the country for another year.

 

Atomic Capabilities

 

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Difficulties encountered by B-45 units, while impairing further the training of jet pilots, posed serious operational problems. The B-45's flaws varied in importance, but were numerous. High speeds affected the Gyrosyn compass and the E-4 automatic pilot, when the aircraft's bomb bay doors were open. (The Gyrosyn compass was the trade name for a compass that consisted of a directional gyro synchronized with the horizontal component of the earth's magnetic field by means of a flux gate-the flux gate detecting the direction of the lines of force and transmitting the information electrically to a procession device.) The emergency brake, which was tied to the B-45's main hydraulic system, was unreliable. Because of poorly designed bomb racks, the bomb shackles became unhooked during certain maneuvers. The B-45's airspeed indicator was inaccurate, and the aircraft's fuel pressure gauges were both difficult to read and erratic. Another safety hazard derived from the engines which, when first started, often caught fire because the aspirator system worked improperly. The temperature gauge of the aircraft's tail pipe, moreover, was so poorly calibrated that it could not indicate the temperatures experienced at high altitudes.

Special problems, with many ramifications, stemmed from the B-45's AN/APQ-24 bombing navigation radar system, and the fact that hardly any B-45s had already received such equipment did not minimize present or future difficulties. Malfunctions of the pressurization pump limited the altitude at which the APQ-24's receiver and transmitter component could operate. The modulator component of the system was not pressurized at all and likewise limited the APQ-24's utility. In addition, the faulty position of the radar antenna affected the coverage of targets as soon as the APQ-24 had to operate at an altitude of 40,000 feet. In fact, the radar system's overall location left a great deal to be desired, a shortcoming shared by several other components. When utilizing the APQ-24, the B-45 observer had to manipulate 2 mileage control dials, placed to his right and about 1 foot behind his back, while observing the radar scope directly in front of him. The layout of the B-45's radar system was not any better from a maintenance standpoint. The Air Force still lacked sufficient qualified personnel for maintenance and repair, and it took 8 hours just to remove and replace the APQ 24's modulator, one of the system's numerous troublesome links. Contributing to the dismal maintenance situation were shortages of spare parts, special tools, and ground handling equipment as well as engine hoists, power units, and aero stands

Prior to 1949, the Air Force did not consider seriously the tactical employment of atomic weapons apart from their use for strategic air warfare. The most important reason was the AAF and Air Force's allegiance to the primacy of strategic air warfare per se.(After the German surrender, AAF leaders declared their long held theory of strategic bombing had been proved that massive bombing of selected vital targets in a nation's interior could cripple its war making capabilities and seriously weaken the people's will to resist. Critics argued that strategic bombing had failed to achieve its objectives, that its cost was excessive, and that tactical air power had made the greater contribution to Allied victory.) Despite the controversy, it soon became obvious that Boeing's spectacular B-17 Flying Fortresses and subsequent B-29 Superfortresses had a greater impact on US. policy than the best known World War II fighters. Another factor was the belief that atomic weapons, because of their great cost and the scarcity of fissionable material, would remain relatively few in number. When the development and large quantity production of small nuclear weapons became probable, the Air Force earmarked such weapons again for strategic use, especially as warheads for proposed guided missiles. Nevertheless, the Weapons Systems Evaluation Group conducted a study on the use of the atomic bomb on tactical targets, after evaluating the effect of the bomb on such targets as troops, aircraft, and ships massed for offensive operations, as well as naval bases, airfields, naval task forces, and heavily fortified positions. Concluded in November 1949, the study found nuclear bombs to be effective on all targets. Although informal in nature, the Weapon Systems Evaluation Group's study was noted by the Air Staff. Yet no action was taken until mid 1950, when the outbreak of the Korean War underlined the weakness of the North Atlantic Treaty Organization forces, should the Russians decide to seize the opportunity to attack in Europe. From then on events moved promptly. The lion's share of the atomic responsibilities, including the retardation mission that normally would fall under the tactical sphere of activities, was retained by the Strategic Air Command (SAC), but the use of atomic or thermonuclear weapons would become Air Force wide. The retardation mission consisted of bombing operations to slow or stop the advances of ground forces. The latter rightly belonged to the fleeting target category, and SAC did not retain the retardation mission permanently.

On November 14, 1950, the Air Staff directed TAC to develop tactics and techniques for the utilization of atomic weapons in tactical air operations (TAC, part of the Continental Air Command since December 1948, regained major command status on 1 December 1950.). The directive received further impetus in January 1951, when an Air Staff program was outlined to ensure that TAC would become atomic capable as soon as feasible. The B-45 was tremendously affected by the new planning. Already established as the Air Force's first multi-jet bomber, the B-45 also became the first light bomber fitted for atomic delivery.

Ordered in the wake of World War II as a SAC medium bomber, the B-45 was designed to carry the A-bomb The deterrent impact of the B-45 remained unknown. Moreover, the aircraft represented but a tiny segment of the Air Force's early atomic armada. But the secrecy surrounding the production of the first atomic weapons created difficulties for which neither the contractor nor the AAF could be blamed. Because of faulty information, the B-45 from the start could not have been used as an atomic carrier without significant internal modifications, the principal obstacle being a large spar extending laterally across the aircraft's bomb bay. However, the problem had become moot quickly, the small, short range B-45 being reclassified as a light bomber in September 1947 and reallocated to TAC. Ironically, the decision to extend the use of atomic weaponry to all combat forces meant that most of the B-45s acquired by TAC would no longer remain under the command's direct control. It also meant that TAC, now due to develop tactical operational techniques with the new weaponry, would have to do so with too few aircraft. In the meantime, the Air Force faced other problems. While the post World War II achievements in the atomic field had been spectacular, and safer and lighter atomic bombs entered the stockpile much sooner than expected, intensive secrecy again had accompanied the new developments. Hence, as in the case of the old atomic bomb, the B-45 would be unable to carry any of the new weapons without first undergoing extensive modification.

In December 1950, 5 months after tentatively earmarking 60 B-45s for atomic duty (Enough for 3 squadrons of 16 aircraft each, plus 12 attrition aircraft. This total, reduced to 40 aircraft in mid 1951, was re increased in mid 1952, when 15 other B 45s were added to the special modification program), the Air Staff directed AMC to modify a first lot of 9 aircraft to carry the small bombs for which designs were then available. This initial project would allow suitability tests by the Special Weapons Command (A separate command of short duration. Established in December 1949, the Special Weapons Command was redesignated Air Force Special Weapons Center and assigned to Air Research and Development Command in April 1952, losing major command status at that time), and give TAC at least a few test aircraft to undertake its new tasks. As a beginning, 5 of the 9 aircraft would be equipped with the scarce AN/APQ-24 system; the remaining 4, with the AN/APN-3 Shoran navigation and bombing system, plus the visual M9C Norden bomb sight. North American would bring the 9 light bombers to the required special weapons configuration for a total cost of $512,000. In mid 1951, the program for operational use of the B-45 in potential atomic operations was established. The aircraft in this program were nicknamed Backbreaker and included, in addition to the B-45 light bombers, 100 of the many F-84 fighter bombers built by the Republic Aviation Corporation (The aircraft were modified F-84Es, identified as F-84Gs). Moreover, the program was accorded a priority second only to a concurrent and closely related modification program involving various SAC bombers. In the early fall of 1951, the program received further impetus. The Air Staff confirmed that modified B-45s, equipment, and allied support had to be supplied to enable units of the 47th Bombardment Wing in the United Kingdom to achieve an operational atomic capability by 1 April 1952. In addition to the first lot of 9 aircraft, the program would count 32 B-45s, the latter aircraft's modification cost being set at $4 million (One B-45A was destroyed by fire in February 1952 and not replaced, thus reducing the total from 41 to 40). Of the $4 million allocated to the project, some of the funds came from other Tactical Air Command projects which had to be canceled. The Air Staff wanted 16 of the planes to be ready by 15 February 1952; the remainder, by 1 April. These were ambitious plans.

 

Modifications and Retirement

 

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Remodeling the B-45 aircraft to the Backbreaker configurations was an extensive operation. Equipment had to be installed in the aircraft for carrying 3 distinct bomb types, and this necessitated some structural modifications to the bomb bay. Special cradles were provided for the 3 types of bombs; and special hoisting equipment was required for loading each type of bomb on the Backbreaker B-45. Then too, a large amount of advanced electronics support equipment had to be added, in place of the standard equipment. Also, the aircraft had to be fitted with a new defensive system and extra fuel tanks. North American and the Air Materiel Command's San Bernardino Air Materiel Area, in San Bernardino, California, shared modification responsibilities for the B-45 Backbreaker program.

In early 1952, the 9 B-45s, already brought to a limited Backbreaker configuration by AMC and North American, were sent by TAC to San Bernardino for completion of the modifications. Complete reconfiguration of the other 32 B-45As also took place at the San Bernardino Air Materiel Area during the first 3 months of 1952, with North American furnishing all necessary kits.

That the work was done without significant delay was noteworthy, for all parties had to overcome serious difficulties. Much of the electronic and support components required for the Backbreaker configuration, being new and of advanced designs, were in very short supply. The requirement for the AN/APQ-24 radar was in direct competition with a SAC special program. Also, the few available AN/APQ-24 sets had to be adapted to the special weapons configuration. Shoran sets, as well, were not readily available, and a quantity had to be diverted from Far East Air Forces' and TAC's B-26 programs.

There were other challenges. Some of the new equipment could not be installed before connecting parts were manufactured. In addition, some needed components simply did not exist. For example, the bomb scoring device, which consisted of a series of switches and relays, was actually manufactured at San Bernardino. The Air Materiel Area also made parts for the A-6 chaff dispenser, including a removable chute for easier maintenance. In the same vein, a special fuel flow totalizer was produced by North American, which likewise manufactured special tie in equipment for the AN/APG 30 radar and the rest of the Backbreaker B-45's tail defense system. Finally, the Fletcher Aviation Corporation of Pasadena, California, produced the extra fuel tanks, while AMC's Middletown Air Materiel Area in Middletown, Ohio, built the special slings that had to be used to carry some of the new bombs.

Atomic capable B-45As began reaching the United Kingdom on May 1, 1952, and deployment of the 40 aircraft was completed on June 12. Once overseas, the support squadron was attached to the 47th Bombardment Wing, now a Third Air Force unit of the United States Air Forces in Europe. This schedule fell about 30 days behind the Air Staff deadline, but was a remarkable achievement considering the project's magnitude.

Not only had the Backbreaker modifications proven exacting, but the Air Force had to cope with various engine problems. As reported by the General Electric Company field representatives servicing the 47th Bombardment Group throughout most of 1951 the J47s powering the Backbreaker aircraft shared some of the flaws of the aircraft's initial engines. Turbine buckets of the new J47s ruptured like those of the Allison J35s. Tail cones fractured just as easily when the J47s functioned improperly. Oil leaks appeared, which meant that the engines had to be removed for repairs and test runs. The Air Force did not expect any new engine to be problem free from the start, but the urgency surrounding the Backbreaker program made these difficulties more significant.

Besides, TAC had to take care of many other tasks. The B-45 deployment called for a somewhat more integrated atomic weapons support system than that used by SAC. TAC had immediately envisioned a concept that actually emphasized the mobility, flexibility, and speed characteristic of tactical air operations. While the TAC concept and the demands it necessarily entailed were not all approved, the Air Staff had endorsed the salient points of the command's proposal. As a result, after being activated on 31 August 1951, the 1st Tactical Support Squadron moved to Europe in the spring of 1952. Once overseas, the support squadron was attached to the 47th Bombardment Wing, now a Third Air Force unit of the United States Air Forces in Europe. (TAC's 47th Wing was at Langley AFB, Virginia, in early 1952. The B-45 overseas deployment prompted the wing's relocation to Royal Air Force Station Sculthorpe, England.)

Like the Backbreaker modification program, the logistic organization and supply system devised by TAC had required much work. Still the system soon was accused of being unwieldy, wasteful of personnel, and unsuited to the support of delivery operations from widely dispersed bases. Modified during the ensuing year, TAC's revised atomic weapons support system was expected to allow greater dispersion in weapon storage and to provide the flexibility essential for varied theater requirements.

In July 1952, the Air Force decided to increase the number of atomic B-45 aircraft by 15. The endorsed configuration was to be that of the Backbreaker aircraft, plus improvements. In short, some electronic changes were needed, the Backbreaker aircraft's tail defense system had to be upgraded, and the fuel flow totalizer, which had been required for the first 40 Backbreaker B-45s but had not been installed because of production delays, was to be added. Another important change, perhaps the most important, called for relocation of the supports required by a specific type of atomic bomb. The supports had to be moved into the forward bay to allow the installation of a 1,200 gallon fuel tank in the rear bay, since the extra fuel would give the aircraft a range increase of almost 300 nautical miles.

In September 1952, after conferring with North American, the Air Force decided on the improved Backbreaker configuration and established a program for procurement and installation of the necessary kits. The Air Force allocated $2.2 million for modification of the 15 additional B-45s, and $3 million for retrofit of the first 40 Backbreaker aircraft. Logically, the San Bernardino Air Materiel Area was to take care of the new modifications and would also provide all necessary kits for the Backbreaker retrofit, which would be done in the field. Although less involved than the original Backbreaker modifications, the new program slipped. During the second half of 1952 the Air Materiel Command was in the process of decentralizing responsibilities from its headquarters to the various air materiel areas. Hence, delays occurred in processing engineering data and purchase requests which, in turn, retarded kit preparation and delivery by North American.

Contractual problems, too, occurred at North American, as the contractor was no longer tooled for the B-45 and was working to capacity on other products. As a result, kit deliveries did not start until July 1953, pushing installation back 4 months. In September 1953, the Air Force added 3 B-45s to the modification program, but as 2 of the original aircraft had been deleted and 1 had crashed, the total still remained at 15. Because no more B-45As were available, 3 of the subsequent models in the B-45 series were modified, postponing the program's completion to March 1954.

While the Backbreaker modifications and retrofit enabled the B-45s to handle several types of small atomic bombs, the modified aircraft were not fitted to deliver the special atomic bombs needed for the retardation mission. (The retardation mission covered the slowing down of enemy troop movements or lines of supply by air interdiction, in this case, tactical bombing.) In 1953, because of the increasing availability of atomic weapons, the Air Force thought of relieving SAC from the retardation responsibility. However, the matter again was dropped, since no tactical aircraft would be able to satisfy the retardation requirements until the Douglas B/RB-66s entered the TAC inventory, a prospect several years away. The classification letter J, like the classification letters X and Y symbolizes the special status of a vehicle, be it an aircraft, a ship, or a missile. The letter or prefix symbol J shows that the vehicle is assigned to a special test program. This program may be conducted in house, or may require a formal loan contract usually referred to as bailment contract. In either case, whatever modifications are made to accommodate testing are temporary. Upon test completion, the vehicle is returned to its original configuration, or returned to standard operational configuration. The same status prefix symbols, or classification letters, are used by all services of the Department of Defense.

Although the A3D, from which the B/RB-66 derived, served well in the tactical role for the Navy, the Air Force bought it without illusions, knowing the Douglas aircraft could not become the tactical bomber truly needed by the Tactical Air Command (TAC). Similarly, the B-57 was ordered for TAC in 1931 as an interim recourse. The Martin B-37, a night intruder bomber primarily, was first earmarked for atomic operations only because the number of B-43s was limited. And as with other post World War II planes, the alternate use of reconnaissance models of the B-37 and B-66 as atomic bombers also was being planned. In any case, not only did production of the B-37 and B-66 slip but the 2 programs proved troublesome, which hardly lessened TAC's predicament.

Other possibilities were entertained in 1953 and 1954. Quantum technological jumps made it likely that small thermonuclear weapons would be obtainable sooner than anticipated. Since modified B 45s and a whole family of fighter bombers could now carry some of the small atomic bombs, modified B 45s and other aircraft presumably could also be made to deliver, within their range limitations, thermonuclear weapons of similar weight and dimensions. Such possibilities, as sound as they later proved to be, in the B 45's case did not go past the theoretical stage.

In January, 1958, less than 50 B-45s remained in the Air Force's operational inventory. These multi jet bombers, the first ever assigned to a combat unit, belonged to the 47th Bomb Wing (Tactical) which, 10 years before, had also been the first to fly them. However, the wing's conversion to Douglas built B-66s was underway, spelling the B-45's end. By July 1958, the obsolescent B-45s had left Sculthorpe Air Station for other bases in Europe and North Africa, where they were briefly used for fire fighting training. Late in the summer of 1958, a few B-45s stood under the hot Spanish sun at Moron Air Base, where they were to be junked and sold for scrap.

 

The B-45A

 

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The B-45A differed from the experimental B-45s in featuring improved ejection-type seats for the pilot and co-pilot and safer emergency escape hatches for the bombardier-navigator and tail gunner. Communication equipment, emergency flight controls, and instruments, installed at the co-pilot's station, also were new. Other improvements included the E-4 automatic pilot, a bombing navigation radar, and A-1 fire control system, all of which were provided as standard equipment. Some of the B-45As were equipped with the AN/APQ-24 bombing-navigation radar system (The AN/APQ-24 bombing navigation radar system made its operational debut with the Convair B-36B.) and such sophisticated electronic countermeasures components as the AN/APT 5; other B-45As only provided for the easy retrofit of this equipment. The first B-45As featured versions of the Allison-built J35 jet engines (in most cases, 4 J35-A-11s), but later aircraft were fitted from the start with the higher thrust jets developed by the General Electric Company, either 2 J47-GE-7s or 2 J47-GE-13s, and 2 J47-GE-9s or 2 J47-E-15s.

The initial production model of the XB-45 flew in February 1948, less than a year after the first flight of the experimental aircraft.

The Air Force began taking delivery of the initial batch of B-45As, 22 of them, in April 1948. These aircraft were identified as B-45A-1s to distinguish them from the subsequent 74 B-45As, known as B-45A-5s. Among other improvements, the B-45A-5s were equipped with more powerfulJ47 engines. As soon as possible, the Air Force assigned 2 B-45A-1s to an accelerated service test program, which was already progressing well by mid July. Under this program, each of the 2 planes accumulated 150 hours of rigorous testing under day and night operating conditions-test results actually accounting for some of the improvements featured by the B-45A-5s. Three additional B-45A-1s were deployed to Muroc AFB to serve as transition trainers in support of the accelerated service test program. Among the base's predecessors was the Materiel Command Flight Test Base (ca 1942), which was redesignated Muroc Flight Test Base in 1944. In 1946, the Muroc Flight Test Base on the north end of Muroc Dry Lake and the Bombing and Gunnery Crew Training Base on the south end of the dry lake were merged into a single flight test center at Muroc Army Airfield under the jurisdiction of the Air Materiel Command. Muroc Army Airfield was redesignated Muroc AFB in February 1948 and became Edwards AFB 1 year later in honor of Captain Glen W Edwards, a USAF pilot killed on 5 June 1948 while testing a prototype jet bomber of the Northrop Aviation's unconventional B 49 "flying wing." Officially dedicated on 27 January 1950, Edwards AFB remained under the Air Materiel Command until April 1951, when the Air Research and Development Command, established as a new major air command in January 1950, assumed jurisdiction. The Air Research and Development Command activated the Air Force Flight Test Center at Edwards AFB on 25 June 1951. The installations, as well as the research and development functions previously assigned to Air Materiel Command, were retained by Air Research and Development Command until 1961, when the newly formed Air Force Systems Command took over.

In effect, most of the early B-45As were relegated to the training task and became known as TB-45A-1s. In later years, however, priorities were to dictate that a few TB-45s be brought up to the combat configuration.

B-45A-5s began reaching squadrons of TAC's 47th Bombardment Wing at Barksdale AFB, Louisiana, in the fall of 1948. Despite slippages, 96 B-45As were completed by March 1950. Unfortunately, during the intervening months financial problems had already begun to take their toll on the B-45 program.

The B-45A production ended in March, 1950, when the Air Force took delivery of the last aircraft.

One B-45A, designated JB-45A, served as an engine test bed for a Westinghouse development. The B-45 light bomber was also tentatively earmarked for a special duty. Believing that utilization rather than aircraft design and construction determined whether a plane was a tactical or a strategic tool, TAC thought the B-45 might be used for close air support operations. There were good reasons for the command's investigation. Sufficient close support of ground forces could not be mustered from the tactical units available in early 1950. Moreover, the bombardment classification of an aircraft in no way obviated the aircraft's potential close air support role. Still, the project was killed in infancy. Tb begin with, the B-45 was not rugged enough to accomplish the necessary ground attack maneuvers. In addition, modification costs to equip the aircraft properly would be quite high. Finally, the extra equipment would compromise the B-45's capability for level bombing.

The Air Force accepted its 96 B-45As over a period of 24 months, the first deliveries being made in April, 1948.

The $73.9 million procurement contract of 1946 provided for 96 B-45As, which would put the aircraft's unit cost below $800,000. However, the basic cost of each B-45A was finally set at $1,080,603-airframe, $682,915; engines (installed), $189,741; electronics, $81,907; ordnance, $552; armament (and others), $125,488. The same price tag was assigned to every model of the B/RB-45. The B/RB-45's identical unit price represented an average reached regardless of contractor or fiscal year procurement and did not reflect engineering change and modification

 

The B-45C

 

Few new features separated the B-45C from the B-45A. The B-45C was equipped for air refueling (The air refueling arrangement consisted of a boom receptacle located on the top of the fuselage, about midway, and of a single point refueling receptacle on the left side aft of the bomb bays) and fitted from the start with wing tip tanks (The B-45C was often flown with 1,200 gallon wing tip tanks; when full, each fuel tank weighed some 7,500 pounds). The RB-45C also looked like the B-45A, except for a small bump on the tip of the aircraft's nose, where a forward oblique camera was enclosed. The RB-45C, in addition, featured a water injection system for increased take off thrust that utilized two 214-gallon droppable tanks suspended beneath the nacelles by means of assisted take off suspension hooks. If preferable, the RB-45C could make use of 2 droppable assisted take off rockets located on the underside of the nacelles. The RB-45C included sweeping internal changes. Five stations were provided, and these stations could mount 10 different types of cameras. However, the crew could not move to the aft camera compartment when the RB-45C was flying; in flight access to the bomb bays was possible, but only if the bomb bays were empty, the bomb bay doors were closed, and the pressurized compartments were depressurized.

North American began working on the B-45C design on September 22, 1947, 2 months after the AAF had endorsed the aircraft's production. Design of the RB-45C was initiated in January, 1949, when the entire B-45 program was significantly reduced. The additional production of 2 B-45Cs and 49 RB-45Cs (Manufacturer's Model NA-162), under contract since 17 June 1948, was canceled either in late 1948 or early 1949. Although money was a factor, the Air Force's belief that a reconnaissance version of the B-47 would be superior to the best RB-45 nailed the cancellation.

The Air Force decided to buy a sizable fleet of B-45Cs on 3 July 1947 and signed the necessary document (Contract AC 18000) in October of the same year. But after only 10 B-45Cs were completed, numerous change orders were issued that drastically altered the October contract. Procurement was limited to the 10 B-45Cs already built, plus 33 airframes that were to be modified on the production lines to serve as photo mapping and reconnaissance aircraft. As it turned out, the RB-45C order marked the end of the B-45 production run. Lt. Gen. Curtis E. LeMay replaced Gen. George C. Kenney as Commander of the Strategic Air Command on 19 October 1948. SAC's new Commanding General had commanded the B-29 strikes against Japan during World War II and lost no time in re-emphasizing to Air Force officials at the highest level the importance of reconnaissance. In fact, every bomber produced after World War II had a genuine reconnaissance counterpart, or could be used for reconnaissance. In the latter case, it might take but a few hours to prepare a given aircraft for the reconnaissance role, or to bring back the reconnaissance bomber to its original configuration. Sometimes the 2 versions of 1 aircraft were assigned to the same unit.

The B-45C first flew on May 3, 1949; the RB-45C in April, 1950.

The Air Force started taking delivery of the B-45C in May 1949 and of the RB-45C in June 1950. Even though a few of the aircraft were deployed overseas in late 1950, no B/RB-45C unit reached an initial operational capability (IOC) before 1951. The RB-45Cs were earmarked for SAC, primarily. The command's inventory reached a peak of 38 aircraft in 1951, some B-45s being included in this total. However, no B/RB-45 aircraft remained on the SAC rolls in 1953. Yet, this did not spell the RB-45's end.

The B/RB-45s were not officially committed to the Korean War, but 3 TAC B/RB-45s reached the Far East in the fall of 1950 (The B/RB 45s were not shown on the Air Force listing of aircraft which participated in any fashion in the 3 year conflict). The small detachment, TAC personnel and civilian technical representatives included, departed for Japan in late September for the express purpose of measuring the reconnaissance capability of a configuration which had not yet been given the most telling of all tests, that of actual combat. Arrival of the RB-45s was well timed, as the RB-29s of the 91st Strategic Reconnaissance Squadron were no longer able to perform with impunity the special missions ordered by Far East Air Forces or the targeting and bomb damage assessment photography desired by its Bomber Command. Eager to maintain its reconnaissance capability in the face of the Soviet built MiG jets, Bomber Command on January 31, 1951 took control of the RB-45 detachment and attached it to the 91st Squadron. The RB-45 crews managed to outrun and outmaneuver the MiGs for several months. Yet, on April 9, 1951, one of the too few RB- 45s barely escaped a numerically far superior enemy. In the ensuing months, while the RB-29s were no longer allowed to enter northwestern Korea, even with escort, the RB-45s could still go into the MiG infested area if they had jet fighter escort. However, after another harrowing experience on November 9, 1951, the RB-45s also were restricted by Far East Air Forces from entering the sensitive areas of northwestern Korea in daylight. In January 1952, the 91st Squadron was directed to convert to night operations, but testing soon showed that the squadron's RB-45s could not be used for night photography because the aircraft buffeted too badly when its forward bomb bay was opened to drop flash bombs. In any case, deficiencies confirmed soon after the RB-45s had reached Japan (The 91st Strategic Reconnaissance Squadron thought the RB-45s were so unsafe for ditching that a Japan based rescue plane held a station orbit over the Sea of Japan each time these planes crossed to Korea), plus the many commitments levied on the 33 aircraft, had foretold the eventual end of the RB-45's Korean experience.

The Air Force accepted 10 B-45Cs and 33 RB-45Cs between May 1949 and October 1951.

The Air Force prorated the basic cost of the entire program ($1.1 million). Consequently, the B/RB-45Cs carried the price tag of the B-45As.

Some B-45s, after undergoing in production modifications, assumed a training role usually assigned to elderly, surplus aircraft. This unusual project took shape early in 1949, when Secretary of the Air Force W. Stuart Symington informed Secretary of Defense James V. Forrestal that future technological trends in aircraft and weapons development called for various types of special training. Even though the procurement of aircraft had been cut, in line with President Truman's fiscal policy, steps had to be taken to keep improving the striking power of the Air Force within the approved 48 group structure. Hence, Mr. Symington recommended and Mr. Forrestal approved the conversion of 16 B-45Cs for tow target duty in order to teach anti aircraft gunners high speed, high altitude firing. The B-45C conversion project, accomplished by North American, was allocated $1.6 million. Broken down, this meant that the modification of each aircraft cost about $80,000 and that $20,000 covered the spare components required by every plane. 'Targets and reels were supplied from current Air Force stocks. But as Mr. Symington had pointed out, there was no exact troop basis for the computation of tow target requirements. The 16 TB 45Cs proved insufficient for antiaircraft gunnery practice, so a few early B-45As were also converted as tow target airplanes. Unfortunately, the low thrust of the Allison J35 engines of the first B-45As prevented the additional conversions from performing well, and the TB 45A association with the tow. target program was of short duration.

Production of the B-45C was completed on 13 April 1950, that of the RB-45C in October 1951, when the last aircraft were delivered. The B/RB-45C phaseout followed the B-45A pattern. In mid 1959, only 1 RB-45C remained in the Air Force inventory.

In early 1950, the Air Force considered using some B-45s as aerial tankers for F-84s carrying special weapons. TAC wanted to know in particular the speed at which refueling, by means of the probe and drogue system, could best be accomplished. The command also asked how much extra fuel could be carried by the B-45, taking into consideration the weight of refueling gear and tanks. Although no actions were taken following these investigations, the Air Force determined that Republic F-84s could operate with a B-45 "Mother" aircraft as a "cell." The most serious handicap would be the necessity for lights during night formation. Without lights, night formation could be conducted with reasonable safety only under bright moonlight. It was also determined that, as a tanker, 1 B-45 aircraft could service 4 planes as well as 2, with the exception that the fuel available for each fighter would be proportionally reduced.

One major milestone took place in 1950, when a SAC RB-45C and a Boeing KB-29B tanker completed the first air refueling of a jet aircraft. On 29 July 1952, a 91st Strategic Reconnaissance Wing RB-45C (Serial Number 48 042), a SAC aircraft commanded by Maj. Louis H. Carrington, made the first nonstop, trans Pacific flight from Elmendorf AFB, Alaska, to Yokota AB, Japan. This flight, made possible by 2 KB-29 in-flight refueling, earned Major Carrington and his 2 man crew the Mackay Trophy for 1952.

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