The F-106A

The F-106 all-weather interceptor was developed from the Convair F-102 "Delta Dagger." Originally designated the F-102B, it was re-designated F-106 because it had extensive structural changes and a more powerful engine. The first F-106A flew on Dec. 26, 1956, and deliveries to the Air Force began in July 1959. Production ended in late 1960 after 277 F-106As and 63 F-106Bs had been built.

The F-106 uses a Hughes MA-1 electronic guidance and fire control system. After takeoff, the MA-1 can be given control of the aircraft to fly it to the proper altitude and attack position. Then it can fire the Genie and Falcon missiles, break off the attack run, and return the aircraft to the vicinity of its base. The pilot takes control again for the landing.

TYPE
F-106A
F-106B Number built/Converted
277
63 Remarks
Imp. F-102; was F-102B
Two-seat trainer

Notes: All Block 1 F-106As (F-106A-1-CO S/N 56-451/467 & 57-229/246) were improved during their service life and re-designated F-106A-31-CO.
Most Block 31 F-106B's (F-106B-31-CO S/N 57-2508/2515) were improved during their service life and re-designated F-106B-81-CO.

SPECIFICATIONS
Span: 38 ft. 4 in.
Length: 70 ft. 9 in.
Height: 20 ft. 4 in.
Armament: One AIR-2A Genie air-to-air nuclear missile and four AIM-4 Falcon air-to-air missiles and one General Electric Vulcan 20mm cannon.
Engine: * One Pratt & Whitney J75-P-17 of 24,500 lbs. thrust with afterburner
Crew: One
Cost: $3,305,435

PERFORMANCE
Maximum speed: 1,153 knots at 35,000 ft.
Combat speed: 588 knots
Combat range: 1,108 nautical miles with full internal fuel load and 1,718 nautical miles with external fuel tanks.
Service Ceiling: 51,100 ft. point intercept mission, max. internal fuel, taking fuel use into account.
COURTESY UNITED STATES AIR FORCE MUSEU

* Unable to locate any further information regarding the P/W J75-P-17 engine.
Pratt & Whitney J75-P-17
The J75, a twin-spool turbojet, was substantially more powerful than the F-102's J57: the J75 produced 76.5 kN (17,200 lbs) at max military power, the same as the F-102 at full afterburner. The J75 had a split fifteen-stage axial flow compressor, composed of an eight-stage low-pressure rotor and a seven-stage high-pressure rotor. The low-pressure rotor was connected to the second- and third-stage turbine wheels with a solid shaft. The J75 also had eight radially mounted combustion chambers, a split three-stage turbine, and an afterburner with a two-position exhaust nozzle. The throttle controlled the high-pressure sections of the engine, but the low-pressure sections were not controllable by the pilot.

Fuel
The F-106 used JP-4. The maximum internal fuel capacity of the F-106A was 5723 L (1514 gallons), including 113 L (40 gallons) in the fuel lines. There was a 151-L (40-gallon) fuselage tank located behind the pilot and a 858 L (227 gallon) tank directly behind the pilot on the upper side of the fuselage on the F-106A. Four fuel tanks were located in each wing, one of which was a transfer tank. The number one tanks were located at the leading edges and held 866 L (229 gallons) combined. Aft of the number one tanks, past a wing spar, the landing gear wells, and another wing spar, were the number two and three tanks, which held 1176 L (311 gallons) and 1603 L (424 gallons), respectively. The transfer tanks, located between the aft spar and the elevons, held 1588 L (420 gallons) combined. The F-106A could hold 7439 L (1968 gallons), or 5808 kg (12,792 lbs) of fuel, including the external drop tanks. The F-106B's maximum capacity was 7318 L (1936 gallons), or 5713 kg (12,584 lbs), due to the smaller tank in the fuselage. Directly aft of the 858-L (227-gallon) tank was the aerial refueling hatch.

The F-106 Ejection Seat

The F-106-A

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STEVEN PATRICK

In mid 1957, when only 120 F-106As had been funded for procurement and Headquarters USAF thought of liquidating the entire program, ADC plans called for an F-106 buildup of 40 squadrons (more than 1,000 aircraft). This total was reduced to 26 squadrons by the end of the year, and another cut took place in September 1958. This last reduction finalized the F-106 force level at little more than one third of the 1,000 aircraft originally sought by ADCs. The decrease was so sharp that the Air Force, despite the extra expense, decided in August 1959 to convert the F-106 test aircraft (35 in all by that time) to operational status.

ADC's 498th Fighter Interceptor Squadron at Geiger AFB, Wash., reached an initial operational capability in October 1959 (5 years later than originally planned). Notwithstanding, the 498th on 21st July scrambled five F-106s on a simulated combat mission with remarkable success. All targets were found and destroyed within 10 minutes after takeoff.

In spite of the initial achievements of the first F-106s, ADC was not fully convinced that it was getting a combat ready aircraft. Generator defects, fuel flow difficulties (particularly acute in cold weather), and fuel combustion starter malfunctions were only a few of the frequent problems. In December 1959, after a canopy had been accidentally jettisoned in flight, all F-106s were temporarity grounded. Some of these early problems persisted a year later.

Testing of the F-106 was extensive. The Category II flight tests conducted at Edwards AFB, after being first accelerated, were extended and did not end until June 1959. Because of a shortage of aircraft, the Category III tests did not begin until July 1969 (a few months after the F-106 entered operational service with ADC's 498th FIS). They were conducted by another ADC unit, the 539th FIS at McGuire AFB, N. J., with the assistance of that command's interceptor and missile school at Tyndall AFB, Fla., where the ADC pilots learned to fire the new interceptor's armament. Category III testing ended in early 1961, after being somewhat hampered by logistical shortages. Meanwhile, justifying ADC suspicion of the F-106's initial combat readiness, each phase of the test programs gave way to important engineering changes. Yet, each change had to be "defined, engineered, reviewed, and approved for production" before modification of aircraft off the assembly line could begin. Hence, by 1960 ADC possessed so many divergent F-106 configurations that maintenance support was almost impossible-a problem partially due to the Cook Craigie production policy re-endorsed in August 1956. Moreover, in spite of successive production line improvements (and an advanced Category III endreport in late 1960 declaring the F-106 operationally suitable) the Air Force still sought ways to enhance the aircraft.

Two major modification projects were undertaken. Wild Goose (started in September 1960 and completed in exactly 1 year), was designed to standardize the F-106 fleet. It was largely retrofit work, mostly done at ADC bases by roving AMC field assistance teams supported by ADC maintenance personnel. Broad Jump (also initiated in late 1960) was a long term program to improve the new interceptor. It took the Sacramento Air Materiel Area an average of 60 days per aircraft to apply Broad Jump, which extended through early 1963.

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The 460 FIS Markings.

Endorsement of the Wild Goose and Broad Jump modifications in the summer of 1960 did not deter the Air Force from seeking further F-106 improvements. Devices for long range detection and electronic counter counter measures (CCM), parametric amplifiers, along with angle chaff, silent lobing, and pulse to pulse frequency shift techniques were among those recommended and, for the most part, eventually approved. Meanwhile, Convair's struggle to provide the F-106 with a better supersonic ejection seat (one that would also work safely at low speed) had sufficiently progressed to warrant installing the new seat in the last 37 F-106A productions and its future retrofit in all others. In 1960 Hughes flight tested an infrared search and track sight that could operate at low altitudes and against varied backgrounds. Tests were so encouraging that the infrared unit was included in the F-106 program of possible improvements, some of which were developed soon enough to become part of the Broad Jump program.

In spite of Wild Goose and Broad Jump changes and Dart Board, another retrofit/modification program {August 1961 April 1962}the F-106 weapon system still had problems. Dart Board had given the aircraft a thermal flash blindness protection hood, provided it with Convair's new Upward Rotational Ejection Seat, and added devices to help correct flameout from fuel starvation (one of the F-106's first deficiencies). But a lot more remained to be done. The MA-1-AWCS, "the most complex, sophisticated and completely integrated automatic weapon control system" designed for an all weather fighter interceptor aircraft, remained unreliable. Correction efforts unabated, the Air Force embarked in two new modification programs. One involved the installation of parametric amplifiers in the MA-1-AWCS to up the system's detection and lock on range by about 30 percent. The other also dealt with the MA-1, mainly to add anti chaff devices. The two new in house modification programs, involving 314 F-106s, were to be completed by the end of 1963.

After divers modification programs, the F-106, the Air Force's first line interceptor since 1959, entered its modernization phase. In 1965 the Air Force awarded a $6.2 million contract for producing new tactical air navigation systems for its best interceptor. The new TACAN, the first to use microelectronic circuits, would be one third the size and weight of the current F-106 navigation system and would provide 450 hours of maintenance free operation. The Air Force in addition approved in house modifications that would give the F-106 an in flight refueling capability for longrange ferrying. The installation of new external wing mounted supersonic fuel tanks, also authorized, would increase the F-106's radius of operation. These modifications would allow F-106 deployment for air defense of US forces overseas in an emergency. They had been applied to two squadrons of F-106s by the end of 1967-just a few months before the North Korean seizure of the USS Pueblo. Modification of the entire F-106 fleet was scheduled for completion by the fall of 1969.

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456 FIS

The F-106 modernization, begun in 1965, would satisfy neither long term air defense requirements nor potential short term ones. The F-106 needed a 20 mm gun (for close attack against hostile fighter aircraft). It required a new canopy (for better observation of the air battle), radar homing and warning equipment (to warn the pilot of enemy air/ground radar and missile launches), and a device to show when maximum turn angle of attack had been reached. In addition, the F-106 could fire its air-to-air missiles in salvo or in pairs, but not singly, and missile preparation took too long. The F-106 weapon system nonetheless remained the best interceptor available, and ADC (still intent upon making it more reliable and easier to maintain) readied for USAF approval a program which was called Simplified Logistics and Improved Maintenance (SLIM). This original SLIM improvement package carried in September 1967 a price tag of $120 million. The Secretary of Defense's decision on 23 November 1967 to discontinue F-12 development and to select the F-106 as the future interceptor to complement a new airborne warning and control system (AWACS) altered ADC planning. The SLIM program was put aside in favor of a more costly one-nearly $1 billion-for the so called (but as it turned out, never to be) F 106X.

As part of the Korean buildup stemming from the Pueblo crisis, a series of F-106 deployments to Korea began. The first F-106s deployed from McChord AFB and conducted in flight refueling en route the first such refueling of F-106s.

When it appeared in late 1968 that the F-106X would not materialize, ADC renewed its efforts to modernize the entire F-106 weapon system which, it believed, had become one of the Air Force's most competent fighters. The original $120 million SLIM program of September 1968 was revived and further simplified. It eventually emerged in mid 1969 as the cheaper Minimum Essential Improvement in System Reliability (MEISR) program ($91 million for 250 F-106A/B aircraft). MEISR would still significantly improve the radar, automatic flight control and DC power system of the F-106 and it was quickly approved by the Air Force. Though MEISR modifications were to be done by AFLC personnel at Hamilton AFB (where ADC's F-106s would be rotated through the 4661st Air Base Group), budgetary constrictions would probably delay completion until sometime in 1973. Despite austere funding, the Air Force in 1969 also endorsed most of Sixshooter-an ADC project outlined in February 1967, after the F-108 had shown the speed and maneuverability for a fighter-to-fighter role. Foremost among the Sixshooter F-106 modernization projects were the addition of a 20 mm. gun (M-61), a lead computing gunsight, a clear cockpit canopy, electronic countermeasures gear, and a RHAW device. The Air Force spent $1.5 million for a Sixshooter "feasibility demonstration" with generally satisfactory results, but eliminated the ECCM improvements recommended by ADC. All other Sixshooter modernization projects were approved, but technical as well as financial difficulties slowed their progress. The Air Force decided in October 1969 that something better than the current (and, in any case, extremely scarce) RHAW equipment would have to be developed to cope with increasingly sophisticated enemy radars. Similarly, installation of the clear top canopy was not expected to begin until January 1972, and testing of the new gunsight, not before mid 1972.

In June 1972 one F-106 entered a Convair flight and fatigue test program to recertify the aircraft for longer service life-8,000 flight hours instead of the current 4,000. This program, expected. to run through mid 1974, would also further evaluate the F-106's new stretched acrylic, clear top canopy.

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An F-106A from the 87th FIS

There were no other configurations of the F-106A. Production of two other F-106 model series, the F-106C and F-106D, was first considered, then dropped. The proposed F-106C would have featured a new engine (JT4B-22), a new fuselage structure, and a variety of technical changes. For example, a new 40 inch radar. that would only slightly decrease the aircraft's absolute altitude and combat radius, but would appreciably increase its "kill" probability by extending search range a minimum of 50 percent. While the F-106D never went past the planning stage, the Air Force in mid 1957 anticipated the production of at least 350 F-106Cs. Two F-106C prototypes were built and accepted by the Air Force in December 1958-a few months after cancellation of the F-106C program. Some 10 years later a third configuration, the so called F-106X, received considerable attention. The F-106X was a basic F-106 that would feature a new radome and a larger radar antenna. It would also receive, among other things, a modified fire control system (providing "look down" capability) and a new air to air missile with "shoot down" capability. Like the superior Lockheed F-12, the so called F-106X did not materialize.

The Air Force accepted 275 F-106As, including the first production aircraft earmarked for testing (later modified for tactical use) and the two F-106s used as prototypes.

The F-106A had a Flyaway Cost Per Production Aircraft of $4.7 million-airframe, $2,090,000; engine (installed), $274,000; electronics, $1,300,000; armament, $950,000; ordnance, $102,000.

The Air Force in mid 1973 retained 174 of the 340 F-106s produced, the last of which had been delivered in December 1960. Seventy three other F-106s were flown by the Air National Guard, ADC's increasingly close partner. Moreover, modernization of the versatile F-106 was in process. Obviously, the upgraded F-106 would be around for many years to come.

An F-106 jet interceptor at Edwards AFB set world speed record of 1,525.695 mph on 11 mile straightaway course, eclipsing the Russian mark of 1,483.84 mph set in an "E-66" delta wing aircraft.

F-106s flew nonstop from McChord AFB to Tyndall AFB for the first extended range interceptor flight marked by inflight refueling and missile firing. In early 1968, air refueled F-106s flew from Richards Gebaur AFB, Mo., to Elmendorf AFB, Alaska.

Global Security

F-106 Squadron Assignments

On May 30, 1959, the first F-106As were delivered to the Air Defense Command's 539th FIS at McGuire AFB in New Jersey, replacing the F-86L. However, the first operational unit was the 498th Fighter Interceptor Squadron based at Geiger AFB in Washington. This was no less than five years later than originally planned. Even then, numerous problems kept the Delta Dart from being declared fully operational until October 31, 1959. The remaining 13 squadrons were re-equipped with the F-106A by the end of 1960.

The 277th and last F-106A was delivered on July 20, 1961. The production run also included 63 F-106B two-seaters, for a total of 340 aircraft.

The F-106 served mainly in the continental United States, in Alaska, Iceland, and in Canada, but it did serve for short spells in Germany and South Korea. Although the F-106 was briefly deployed to Osan AFB in Korea in February of 1968 to provide air defense during the *Pueblo* incident, the Delta Dart never saw any combat.

Air Defense Command Squadron Assignments:

2nd Fighter Interceptor Squadron (1971-1972)

5th Fighter Interceptor Squadron (1960-1985)

11th Fighter Interceptor Squadron (1960-1968)

27th Fighter Interceptor Squadron (1959-1982)

48th Fighter Interceptor Squadron (1960-1982)

49th Fighter Interceptor Squadron (1968-1987).

71st Fighter Interceptor Squadron (1960-1971)

83rd Fighter Interceptor Squadron (1971-1972)

84th Fighter Interceptor Squadron (1968-1981)

87th Fighter Interceptor Squadron (1968-1985)

94th Fighter Interceptor Squadron (1960-1969)

95th Fighter Interceptor Squadron (1959-1973)

318th Fighter Interceptor Squadron (1960-1983)

319th Fighter Interceptor Squadron (1960-1963 and 1971-1972)

329th Fighter Interceptor Squadron (1960-1967)

437th Fighter Interceptor Squadron (1968-1968)

438th Fighter Interceptor Squadron (1960-1968)

456th Fighter Interceptor Squadron (1959-1968)

460th Fighter Interceptor Squadron (1968-1974)

498th Fighter Interceptor Squadron (1959-1968) .

539th Fighter Interceptor Squadron (1959-1967)

From 1972 onwards, the McDonnell Douglas F-15 Eagle gradually began to replace the Delta Dart in ADC squadrons. As they were removed from Air Force service, they were passed along to the Air National Guard. First ANG unit to receive the F-106 was the 186th FIS of the Montana ANG, based at Great Falls, which took delivery of its first planes on April 3, 1972. Six ANG units flew the F-106 on Air Defense Command mission. The last Delta Dart-equipped Air Force squadron, the 119th FIS based at Atlantic City, New Jersey flew its final alert duty on July 7, 1988. The ANG units continued to fly the last few Delta Darts for only a few months longer after the USAF had relinquished the type. The last ANG to relinquish its F-106s was the 119th FIS of the New Jersey ANG, which sent its last plane to AMARC in August of 1988.

Air National Guard Squadron Assignments

101st Fighter Interceptor Squadron, Massachusetts Air National Guard (1972-1988)

119th Fighter Interceptor Squadron, New Jersey Air National Guard (1972-1988)

159th Fighter Interceptor Squadron, Florida Air National Guard (1974-1987)

171st Fighter Interceptor Squadron, Michigan Air National Guard (1972-1978)

186th Fighter Interceptor Squadron, Montana Air National Guard (1972-1987)

194th Fighter Interceptor Squadron, California Air National Guard (1974-1984)

Sources:

1. Convair F-106 Delta Dart, Robert F. Dorr, Wings of Fame, Vol 12, 1998

F-106 Test Programs

The F-106 was utilized as a flying test platform for a number of new equipment and weapons development programs, some of which included:

Satellite Killer Program

The Satellite Killer program tested the theory and practicality of an air launched missile that was designed to track and intercept enemy reconnaissance satellites and orbiting weapons platforms in low to medium altitude orbits.

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The 4750th was the "Skunk Works" of the Air Defense Weapons Center, testing various air-to-air weapons concepts. This F-106 has a camera in the Vulcan cannon housing.

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A standard AAM is seen on the starboard wing fuel tank pylon of a 4750th Test Squadron F-106A. It is not clear if live firing tests were conducted with the Delta Dart, or if actual XAIM-97 rounds were ever carried