Convair F-106A Delta Dart
Last revised December 18, 1999
Written by: Joseph Baugher
The Convair F-106A Delta Dart is regarded by many as being the finest
all-weather interceptor ever built. It served on active duty with the US Air
Force for almost 28 years, much longer than most of its contemporaries.
The F-106 had its origin in an early-1949 request by the USAF for an advanced
interceptor capable of supersonic performance that would surpass the speed and
altitude performance of new Soviet intercontinental bombers which intelligence
services warned would soon be available. The North American F-86D Sabre, the
Northrop F-89 Scorpion, and the Lockheed F-94 Starfire were all subsonic
aircraft, and were deemed to have insufficient growth potential to be able to
meet this new threat. This project came to be known as the "1954 Interceptor",
after the year that new interceptor would supposedly be entering service.
At that time, the Air Force recognized that the increasing complexity of
modern weapons made it no longer practical to attempt to develop equipment,
airframes, electronics, engines, and other components in isolation and to expect
them to work properly when they were put together in the final product. To
address this problem, the Air Force introduced the "weapons system" concept, in
which components of the the new interceptor would be integrated with each other
from the very beginning, making sure that the various systems would be
compatible with each other when they were incorporated into the final aircraft.
The project was given the designation WS-201A, where WS stood for "Weapons
System". As originally conceived, WS-201A was a weapons system consisting of
air-to-air guided missiles, all-weather search and fire control radar, all
housed in an airframe capable of supersonic flight.
The electronics package for the new WS-201A system came first. Project
MX-1179 was the designation given to that portion of the project dedicated to
the armament and electronic fire-control system of the 1954 Interceptor. In
October of 1950, the Hughes Aircraft Company was named the winner of the MX-1179
contract. The Hughes proposal consisted of a MA-1 fire control system acting in
conjunction with GAR-1 Falcon air-to-air guided missiles. For a brief time, the
Falcon missile was known as the F-98, a fighter designation.
The airframe part of the project was designated MX-1554. Proposals for the
airframe portion were requested by the Air Force on June 18, 1950. When the
bidding closed in January of 1951, nine proposals had been submitted by six
different manufacturers. Republic submitted three separate proposals, North
American submitted two, and single proposals were made by Chance-Vought,
Douglas, Lockheed, and Convair.
On July 2, 1951, the Air Force announced that designs by Convair, Lockheed,
and Republic had been selected to proceed with preliminary development. All
three companies were to proceed with their designs all the way to the mockup
stage, with the design deemed most promising at that time being awarded a
production contract. Later, the USAF deemed it too costly to carry through with
three concurrent development programs, and it cancelled the Lockheed project in
its entirety. The Convair and Republic entries were given the go-ahead to
The Republic entry bore the company designation of AP-57, where the AP stood
for "Advanced Project". It called for an extremely advanced aircraft capable of
achieving a Mach 4 performance at altitudes of up to 80,000 feet. This was
clearly a quantum leap in the state of the art for the early 1950s.
The Convair entry in the MX-1554 project was closely related to the
experimental XF-92A which Convair had built in 1948 as a test bed to provide
data for the proposed F-92 Mach 1.5 fighter. This work had been performed in
consulation with Dr. Alexander Lippisch, who had done pioneering work in Germany
on delta-winged aircraft during the war, and Convair had become convinced that
the delta configuration provided a viable solution to the problems of supersonic
flight. The XF-92A had been the first powered delta-wined aircraft to fly, but
the F-92 project had itself been cancelled before any prototype could be built.
On September 11, 1951, Convair received a contract for its delta winged
design which was assigned the designation F-102. Work on the competing Republic
design was also authorized, and that aircraft was assigned the designation
XF-103. However, the XF-103 was so far ahead of the state of the art that it was
deemed too risky to be a serious contender for the 1954 Interceptor project,
which made the F-102 for all practical purposes the winner of the contest.
The Air Force authorized the fitting of a Westinghouse J40 turbojet in the
first few examples of the F-102, but later production aircraft were to be
powered by the appreciably more-powerful Wright J67 turbojet, which was a
license-built version of the Bristol Olympus. The J40-powered F-102 was to be
capable of a speed of Mach 1.88 at 56,500 feet, with the J67 production version
capable of Mach 1.93 at 62,000 feet.
In order to expedite the development of its 1954 Interceptor program, the Air
Force adopted the so-called "Cook-Craigie" program, named for its originators,
Generals Laurence C. Craigie and Orval R. Cook. During the late 1940s, these two
officers had developed a concept of an aircraft development program in which the
usual prototype stage would be skipped. Instead of waiting to start full-scale
production until the prototypes had passed flight testing and the bugs had been
ironed out, the Cook-Craigie plan called for the delivery of a small number of
production aircraft during the flight testing phase so that any major changes
could be incorporated into permanent factory tooling in order for combat-ready
aircraft to be delivered when mass production started. This program is
inherently risky--it can produce a new combat aircraft in a hurry if everything
goes according to plan during flight testing, but can result in a lot of costly
and time-consuming fixes in the field if unexpected problems turn up. The
Cook-Cragie plan is really viable only if there is a high degree of confidence
that the aircraft is really going to go into production. Since the F-102 was
basically a scaled-up XF-92A, the risk was deemed work taking.
By December of 1951, it was apparent that the Wright J67 engine and the MA-1
fire-control system would not be ready in time. This forced the USAF to change
its plans. At that time, the Air Force decided to proceed with an interim
version of its 1954 Interceptor, one which could be introduced into service at
an early date, pending the availability of the fully-developed version at a
later time. The interim version was to be designated F-102A, with the
fully-developed advanced version being designated F-102B. The F-102A was to be
powered by the less-powerful Pratt & Whitney J57 turbojet, but the F-102B
was to retain the high-thrust J67. The F-102A would be equipped with an interim
fire-control system, but the F-102B would be equipped from the outset with the
highly-sophisticated fire control system being developed by Hughes under project
Although the F-102A was considered only as an interim version pending the
availability of the F-102B, the F-102A ran into some unexpected developmental
difficulties and fell behind schedule. A lot of money that had originally been
planned for the F-102B now had to be diverted into fixing the F-102A's problems.
Consequently, the F-102B fell even further behind schedule and began to lose
some of its original high priority.
By mid-1953, the MX-1179 fire control system (later to be known as the MA-1)
was slipping badly, and it took another year before an experimental installation
could be installed aboard a T-29B for testing. At the same time, the Wright J67
engine was experiencing difficulties of its own. The Air Force had to consider
alternative powerplants, and finally settled on the Pratt & Whitney J75,
which was an advanced version of the J57 which was used in the F-102A. The
substitution of the J75 engine for the J67 was approved in early 1955.
Seventeen F-102Bs were ordered in November of 1955. Their serials were
56-451/467. The F-102B mockup was ready for inspection in December of 1955. On
April 18, 1956, the Air Force finalized the F-102B production contract of the
previous November, earmarking all of the 17 aircraft ordered exclusively for
testing. One prototype was to be delivered in December of 1956, with the others
to follow in January of 1957.
On June 17, 1956, the designation of the F-102B was changed to F-106A. This
redesignation was a recognition of the past technical differences that had
distorted the original F-102 program and also a recognition that the F-102B was
by now a completely different aircraft from the F-102A and was far more
In September of 1956, the Air Force specified that the F-106A would be
available by August of 1958 (some four years later than initially planned) and
that it had to compatible with the Semi-Automatic Ground Environment (SAGE) up
to a radius of 430 miles and an altitude as high as 70,000 feet. Interceptions
would be accomplished at speeds of up to Mach 2 at 35,000 feet. It was to be
capable of launching air-to-air guided missiles and rockets under the control of
the Hughes MA-1 fire control system.
The wing of the F-106A was virtually identical to that of the F-102A. The
aircraft with FY 1956 serial numbers had outer-wing boundary layer fences as on
the F-102A, but these were replaced on FY 1957 and later aircraft by leading
edge slots. The wing was "wet" with no fuel bladders. Fuel transfer was
accomplished by low air pressure bleeding off low-psi air pressure from engine
into tanks. It was thought, however, that combat damage (even perhaps a single
bullet hole in the wing) could incapacitate the entire system.
The major external difference was in the fuselage, which had a much more
streamlined shape. The variable-ramp air intakes were moved well aft of the nose
and mounted closer to the engine. The shape of the fin and rudder were changed
and a clamshell-type airbrake was fitted at the base of the vertical fin.
A new undercarriage was fitted with steerable twin-nosewheels.
On the first F-106s, the upper and lower rotating navigation beacon lights
(located immediately aft of the canopy in the dorsal position and immediately
behind the nosewheel on the belly of the aircraft) retracted when the aircraft
went supersonic. In later years, this feature was disabled.
The Pratt & Whitney J75 twin-spool, axial-flow afterburning turbojet was
the same engine which powered the Republic F-105 Thunderchief. It was rated at
15,000 lb.st dry and 23,500 lb.s.t with afterburner.
The pilot sat well ahead of the engine air intakes. As with the F-102, the
F-106 featured optically-flat windscreens which met at their forward edges. The
metal strip that was located where the windscreens met was directly in front of
the pilot's face and severely restricted his forward vision.
As on the F-102A, the all-missile armament was housed internally in a
spacious ventral weapons bay that was closed by pneumatically-operated
double-folding doors. The all-missile armament consisted of a single Douglas
MB-1 (AIR-2A or 2B) Genie unguided missile equipped with a 1.5 kT nuclear
warhead plus four Hughes GAR-3 Falcon radar- homing or GAR-4 infrared-homing
(later redesignated AIM-4E and AIM-4G respectively) air-to-air missiles. The
unguided 2.75-inch missile armament of the F-102A was omitted.
The Genie missile was carried in the rear half of the missile bay. It was
powered by a 36,600 lb.st. Thiokol TU-389 rocket motor and was unguided, relying
on its 1.5 kT nuclear warhead to ensure a kill. Launch weight was 822 pounds and
maximum velocity was Mach 3.3. Snap-out fins gave the missile stability during
flight. Range was about 8 miles, and flight time to target was about 12 seconds
and a blast radius of about 1000 feet.
The Falcons were conventional warhead adaptations of the nuclear-tipped
AIM-26A Falcon. The two semi-active radar homing AIM-4E Falcons were carried in
the forward half of the weapons bay, whereas the AIM-4G infrared-homing missiles
were carried in the rear half of the weapons bay flanking the Genie missile. All
Falcon missiles were contact fused, with the fuses located on the leading edges
of all four fins, so that a direct hit on the target was needed to score a kill.
The Falcon missiles could be launched in salvo or in pairs. Because the
aerodynamic range of the AIM-4F was greater than the range of its seeker and
tracker radar sensor, the IR-guided AIM-4G was the preferred means of attacking
a fast-moving target. At high closure speeds, the MA-1 fire control system would
present two separate firing solutions, one for the AIM-4G and the other for the
AIM-4F. If all four missiles were to be fired, the 4Gs were fired first so that
they would not inadvertently lock onto the radar guided missiles rather than the
target. As a further precaution, the 4F pair was carried in the rear bay. The 4F
and 4G missiles were fired in like pairs and ripple-fired so that one would
always be ahead of the other. The missiles were fired in pairs because the
pneumatic system had only enough high pressure stored for three cycles of the
armament system. There were essentially three shots available-one Genie, one
pair of AIM-4Fs and one pair of AIM-4Gs.
The Hughes MA-1 fire control system incorporated the first digital computer
to be built into a fire control system. A datalink with NORAD's SAGE system
meant that radio silence could be maintained throughout the intercept, while an
autopilot allowed the ground controllers to "fly" the aircraft during the final
approach to the target. A Tactical Situation Display (TSD) between the pilot's
feet showed a moving map of the route across the ground during the intercept.
The first F-106A (56-0451) was finally available by the end of 1956. The
first flight was made by Convair test pilot Richard L. Johnson at Edwards AFB on
December 26, 1956. He was the same pilot who had made the maiden flight of the
F-102. The flight was not entirely glitch-free--it had to be aborted early due
to air turbine motor frequency fluctuations, and the speed brakes opened but
would not close. Consequently, the aircraft did not go supersonic on its first
flight. The second aircraft (56-0452) followed on February 26, 1957. They were
both powered by the YJ75-P-1 engine. The first two aircraft were not equipped
with the MA-1 system, carrying nose ballast to compensate for the missing
The test and development work on the F-16 was divided into six phases. Phase
I was conducted by the contractor, and Phase II was conducted by the Air Force.
Phase II tests wee carried out between May and June of 1957. The first 12
aircraft off the production line were devoted to tests at Edwards AFB in
California. They differed from the prototypes in having J75-P-9 engines. Early
testing reached a speed of Mach 1.9 and an altitude of 57,000 feet, but this was
still well below expectations. In addition, the F-106A's acceleration was
significantly below Convair's estimates, and it took almost 4 1/2 minutes to
accelerate from Mach 1 to Mach 1.7 and another 2 1/2 minutes to accelerate to
Mach 1.8. With such poor acceleration, it was felt that Mach numbers above 1.7
would not be tactically usable.
The poor speed and acceleration was cured by altering the aircraft's air
intake cowling and charging ejectors. The capture area of the intake ducts was
enlarged and the duct lips were thinned down. There were also problems with the
reliability of the J75-P-9 engine. Eventually, the more powerful J75-P-17 engine
was substituted, which was rated at 17,200 lb.s.t. dry and 24,500 lb.s.t. with
afterburner. There were further problems with the MA-1 fire control system and
with the cockpit layout. Originally, the control column had occupied the
traditional center location, but was later moved to the side at USAF insistence
in order to ensure an unrestricted view of the Horizontal Situation Indicator.
This arrangement turned out not to be viable, and the control column was later
moved back to the center and provided with a two-handed grip for both radar and
aircraft control. The right-hand grip was used for control of the aircraft and
the left-hand grip was used for operation of the radar. A button in the middle
of the yoke gave the pilot control of the radar antenna, and another button on
the left grip enabled the pilot to put the pipper on the target by following
directions on the radar scope. The pilot selected the missiles to be fired by
using a switch on the left console, with the trigger that was used to launch the
missiles being on the right hand grip.
Early test aircraft had explored both conventional round-faced instrument
panels and panels with vertical-tape instruments. However, the first three
squadrons of F-106As were sent to the field with analog or round instrument
dials. Eventually, the vertical-tape instrument set (know as Integrated
Instrument Display, or IID) was made standard with aircraft 58-0759. Some of the
early aircraft were subsequently upgraded with IID, but many never got the
Initial aircraft had boundary layer fences as on the F-102, but production
aircraft had wing leading-edge slots instead. The first twelve aircraft were
temporarily designated JF-106A for flight tests, but a total of thirty-seven
(including the first two aircraft) were used for flight test development.
In mid-1957, the F-106A was given the popular name Delta Dart.
Originally, the Air Force had planned to acquire 1000 Delta Darts, enough to
equip some forty Air Defense Command (ADC) squadrons. However, by 1957 the
delays in the F-106 program and the problems with the engine and the fire
control system had resulted in the necessity of other interceptors such as the
McDonnell F-101B Voodoo having been ordered as a stop-gap measure, and the F-106
had lost some of its urgent priority. For a while, serious consideration was
given to cancelling the entire F-106 program, or else to redesigning the
aircraft as a long-range interceptor. Although the F-106 survived intact,
shortages of funds caused a drastic cutback in the number of F-106As on order.
By September 1958 the total order of F-106 interceptors had been cut by a factor
of three, enabling only fourteen squadrons and a training unit to be equipped.
As a result, only a further 260 F-106As were ordered. Since the cutback was so
drastic, a decision was made in August of 1959 to convert all of the existing 35
F-106A test aircraft to operational status (Model 8-24 standards) and turn them
over to the interceptor squadrons.
In September of 1958, an early F-106A (serial number 57-0235) was allocated
to Ames Research Center at Moffett Field in California for tests of the MA-1
fire control system.
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.
On December 15, 1959, a Delta Dart (56-467) flown by Major Joseph W. Rogers
set a world's absolute speed record of 1525.96 mph at 40,500 feet. This beat the
previous record of 1483.83 mph, set by Georgiy Mossolov in the Soviet Ye-6/3 on
October 31 of that year.
Initial operational deployment turned up all sorts of problems--generator
defects, fuel-flow deficiencies (particularly acute in cold weather), and
fuel-combustion-starter malfunctions. In December of 1959, after a canopy had
been accidentally jettisoned in flight, all F-106s were temporarily grounded
until the problem could be fixed.
The MA-1 fire control system carried by the F-106A was initially quite
unreliable and was subjected to lots of in-service modifications in an attempt
to fix its chronic problems. The MA-1 system was upgraded no less than 60 times
during the Delta Dart's long service life. In 1960, devices for long-range
detection and electronic counter-countermeasures equipment were added, along
with the capability for using angle chaff, silent lobing, and pulse-to-pulse
frequency techniques. Anti-chaff devices were added in an effort to defeat enemy
attempts to confuse the fire control system by dropping bits of radar-reflective
strips. The modification programs involved 314 F-106As and were completed by the
end of 1963.
The F-106A operated in conjunction with the SAGE (Semi-Automatic Ground
Environment) network which was linked via the Hughes MA-1 fire-control system to
the F-106. It operated by plotting the course needed to intercept an enemy
aircraft, automatically sighted the target, fired the air-to-air missiles, and
then automatically placed the F-106 on the correct course to disengage. The
F-106 could actually be fully computer-flown during most of its mission, the
pilot actually being needed only for takeoff, landing, or in case something went
wrong with the automation.
Flight testing continued until early 1961, with each phase of the test
program turning up a whole host of problems which required important engineering
changes. Each change had to be defined, engineered, reviewed, and approved for
production before modification of aircraft off the assembly line could begin.
The Cook-Cragie production policy only made problems worse, and by 1960, the Air
Defense Command had so many different F-106 configurations out in the field that
maintenance support was a nightmare.
Because of the numerous modifications to the MA-1 fire control system made
during production, a major modification project named *Wild Goose* was initiated
in September of 1960 to bring the earlier F-106s up to the latest production
standard. Early in 1960, ADC could list 63 changes in the F-106A's fire control
system and 67 changes in the airframe that would be required to make early
F-106s equivalent to the machines currently coming off the production line.
Lasting a full year, the program involved roving AMC field assistance teams
supported by ADC maintenance teams working at ADC bases.
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.
In late 1961, Secretary of Defense Robert S. McNamara spoke of reopening the
F-106 production line to build another 36 aircraft (rather than the 80
originally budgeted for in FY 1961). However, the ADC had heard so much about
the capabilities of the Navy's F4H-1 Phantom two-seat interceptor that it
thought that it might be a better idea to purchase some F4H-1s rather than buy
additional F-106s. The USAF called for a competition-named Project High
Speed-between the F-106 and the Navy's F4H-1 Phantom. It was designed to
evaluate the capabilities of these two aircraft to perform similar missions.
During the competition, the Phantom's APQ-72 radar was more reliable and had
longer detection and lock-on ranges than the MA-1 system of the F-106. However,
in many sorties F-106 pilots "shot down" their F4H adversaries in visual range
combat situations. In the event, neither aircraft got the nod for additional ADC
interceptor orders, and in December of 1961, the USAF announced that the
F4H/F-110 would be acquired for the Tactical Air Command and that ADC would get
no new interceptors.
Even after all aircraft had been delivered, reliability problems continued to
plague the MA-1 and ASQ-25 systems. Throughout its long service life, the F-106A
was continually upgraded and improved to correct these problems. The *Broad
Jump* modification program started in late 1960 was a long-term program for
general improvements in the F-106A. This program was carried out by people at
the Sacramento Air Material Area, and it extended through early 1963. Among the
changes introduced by this program was the fitting of an infrared
search-and-track sight that could operate at low altitudes and against varied
backgrounds. The unit retracted into a fairing in front of the cockpit.
In 1962, F-106As were fitted with a Sheaffer Spring Hook arrester system
designed to engage wires at the end of the runway in the event of an landing
overshoot, becoming the first USAF combat aircraft to be so equipped. The F-106A
was definitely NEVER intended for carrier-based operations! :-)
The F-106 had to be grounded again on September 26, 1961 to make repairs to
the fuel system which had caused two crashes. This order did not affect the
F-106s that were on alert with ADC, but it did affect those used for training
and transition flying. In response to this grounding, the *Dart Board* retrofit
and modification program took place in 1961-62. This program finally fixed the
problem with flame-outs from fuel starvation which had affected earlier Delta
Darts. A thermal flash blindness protection hood was also fitted. Perhaps the
most significant of these changes was, however, the revision of the ejection
system for the F-106.
The ejection seat fitted to early F-106s was a Weber-built variation of the
seat used by the F-102. It was an open, catapult-only seat which used an
explosive charge to throw it out of the aircraft. It was thought that this seat
would be inadequate for ejections at supersonic speeds, and it was replaced by a
Convair-designed "B"-seat. It is not sure what the letter B stood for, but
pilots believed that it was so named because it resembled a bobsled. It was
designed with supersonic ejection specifically in mind. It was demonstrated in
15 sled tests and 11 flight tests. The first live test ejection with the
Convair-designed seat took place when Technical Sergeant Games Howell ejected
safely from an F-106B piloted by Major James Hendrix on June 6, 1961.
The ejection sequence with the Convar B-type seat was quite complicated. The
pilot initiated the sequence by pulling a D-ring, which jettisoned the canopy,
retracted and locked the shoulder harness, retracted the occupant's feet, and
raised the foot pans, seat pan and leg guards. While all this was happening, the
pilot had to pull the D-ring a second time to disconnect the seat actuator and
fire the vertical thruster which propelled the seat up on its rail. The
rotational thrusters then fired, causing the seat to rotate into a horizontal
position on top of the aircraft. Once there, gas-operated stabilization booms
extended, attachment bolts fired, and the rocket motor ignited to propel the
seat away from the aircraft.
The new Convair-designed ejector seat was not very popular with F-106 pilots,
and there were some unsuccessful ejections that resulted in pilot fatalities.
Frustrated with the complexity and unreliability of the Convair B-seat, the USAF
contracted in 1965 with the Weber Aircraft Corporation for the design of a
"zero-zero" seat for the F-106. It was recognized that high-altitude supersonic
ejections were actually quite rare, and that the high-runner cases were more
likely to be ejections at relatively low altitudes and low speeds. Weber
delivered the first seat in only 45 days. The new Weber seat was quite
effective, and was quickly retrofitted through the entire F-106 fleet.
In 1965, an new TACAN system was installed which used microelectronic
circuits and was one-third the size and weight of the existing system.
The F-106A surprised everyone by having a good maneuverability and showing
potential as being an excellent dogfighter. There was some thought to using the
F-106 for top cover in Vietnam. Among the suggestions was to apply tactical
camouflage, to fit a clear-view canopy, and to add an internal cannon armament.
Although the F-106 never actually did serve in Vietnam, the suggestion of the
addition of a gun was taken seriously. The gun was not intended for air-to-air
combat against enemy fighters, but was primarily intended to provide extra
firepower for a better close-in kill potential against enemy bombers, but it was
thought that it might also be useful in attacking bombers flying at low
In support of this program, Convair issued a proposal to re-equip the F-106
with an internal cannon, an optical gunsight, and a clear-view cockpit canopy in
a program known as Project Sharp Shooter. An internal 20-mm M61A1 rotary
cannon with 650 rounds was fitted inside the rear half of the weapons bay,
replacing the Genie nuclear-tipped rocket. However, the four AIM-4F/G Super
Falcon missiles could still be carried. The gun system was installed as a
package inside an enclosure which was mounted inside the missile bay and which
provided an aerodynamic shield for the portion of the gun protruding below the
missile bay. Gun-equipped F-106As could be distinguished by a bulged fairing
underneath the fuselage which provided clearance for the rotating barrels of the
cannon. As part of the program, a new "clear-topped" canopy was tested, which
eliminated the metal strip above the pilot's head, markedly improving the
cockpit visibility, at least immediately above.
The gun installation was first tried on F-106A 58-795 and subsequently on
59-092. A prototype gunsight was developed at Tyndall AFB. The gun was installed
only on those F-106s that had vertical tape instruments. When firing, the Vulcan
was limited to only 4500 rounds per minute (rather than the 6000 rpm available
when installed on the F-4E) due to limitations in the hydraulic pump which
rotated the weapon. However, this innovation was not provided for the F-106B
two-seater. The first test of the gun installation took place on February 10,
1969 on 58-795.
The idea of painting the F-106 in camouflage scheme was abandoned, when it
was found that there was no significant advantage in doing so. In the event, the
F-106 never went to Vietnam.
In the late 1960s, the F-106 was provided with newly-designed larger-capacity
underwing tanks. These new tanks were often called "supersonic tanks", since
they could be carried underneath the wings at any speed. They had a 360
US-gallon capacity, 50 percent larger than the 227-gallon tanks that were
previously carried. The tanks were jettisonable, but this capability was rarely
used in practice. The tanks were routinely carried on all but the shortest-range
In conjunction with the new underwing tanks, an inflight refuelling
capability was retrofitted to all surviving F-106s. This was done by
retrofitting a slipway receptacle in a dorsal position behind the pilot. The
first refuelling installations were installed in 1967.
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
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.
During its long service life, the F-106A had the distinction of recording the
lowest single-engined aircraft accident record in USAF history. Despite this,
out of a total production of 340 aircraft, 112 (including 17 two-seat F-106Bs)
were lost in crashes or in ground fires during the 29 year career of the Delta
As F-106As were withdrawn from active duty, they were ferried out to
Davis-Monthan AFB in Arizona where they were placed in storage. The first F-106
went to storage in January of 1982. The last three F-106s (from the Atlantic
City-based 119th FIS of the New Jersey ANG) departed for Davis Monthan AFB in
August of 1988.
In 1986, a contract was awarded to Flight Systems Inc. (later Honeywell) to
modify 194 surplus Delta Darts stored at Davis-Monthan AFB in Arizona to QF-106A
target drone configuration. This program came to be known as Pacer Six,
and the first flight of a converted drone took place in July of 1987. Following
the completion of an initial batch of ten QF-106s in 1990, most of the work was
transferred to the USAF itself. Much of the conversion work was done before the
aircraft were removed from storage at AMARC, with further work being carried out
at East St Louis, Illinois. The QF-106s began operating as a Full-Scale Aerial
Target (FSAT) in late 1991 at White Sands Missile Range in New Mexico, and later
at the Eglin Gulf Test Range in Florida (based at Holloman and Tyndall). A
typical mission would employ the QF-106 as a target for an infrared homing
missile. The aircraft had burners placed on pylons underneath the wings to act
as IR sources for heat-seeking missiles, but it must be admitted that no real
enemy would be so accommodating as to add these burners to make their planes
better targets. However, the intention of the program was for the QF-106 to
survive repeated engagements with air-to-air missiles, to make it possible for
each QF-106 to last as long as possible before it was destroyed. The last
shootdown of a QF-106 (57-2524) took place at Holloman AFB on February 20, 1997.
Today, the QF-106 has been replaced by QF-4 Phantom drones.
The last mission flown by an F-106 was as a participant in Project
Eclipse, a joint USAF/NASA project to demonstrate the validity of a concept
for a reusable launch vehicle that would carry payloads into orbit. QF-106
59-130 was towed into the air by an NC-141A Starlifter (61-2775) by using a
synthetic rope. The first flight was made on December 20, 1997 and the last test
took place on February 6, 1998. The tests were made to explore the feasiblity of
having a Boeing 747 to tow a RLV known as the Astroliner to 45,000 feet, where
the Astroliner would fire its rocket engines and fly into orbit. On May 1, 1998,
this last flyable F-106 flew from Edwards to AMARC. I do not believe that this
concept was explored any further.
Today, there are 10 F-106s in museums, and at least 21 are still in storage
at Davis Monthan AFB. Some of these may end up in museums as well.
Specification of F-106A:
Engine: One Pratt & Whitney J75-P-17 turbojet, 17,200 lb.s.t. dry and
24,500 lb.s.t with afterburning. Performance: Maximum speed: 1525 mph at 40,000
feet (Mach 2.31), 1327 mph at 35,000 feet. Landing speed was 173 mph Initial
climb rate was 42,800 feet per minute. Service ceiling was 57,000 feet. Combat
radius was 575 miles. Maximum range with maximum external fuel was 1809 miles.
Maximum ferry range was 2700 miles at 610 mph at 41,000 feet Weights were 23,646
pounds empty, 38,700 pounds combat weight, 35,500 pounds gross, and 41,831
pounds maximum takeoff. Dimensions: wingspan 38 feet 3 1/2 inches, length 70
feet 8 3/4 inches, height 20 feet 3 1/4 inches, wing area 697.8 square feet.
Maximum fuel load was 1440 US gallons. Armament consisted of one Douglas MB-1
(AIR-2A or 2B) Genie unguided missile with a nuclear warhead of 1.5 kT yield and
four Hughes GAR-3 or GAR-4 (later redesignated AIM-4E and AIM-4G respectively)
radar or infrared-homing missiles. All these missiles were housed within the
internal weapons bay. In later installations, a single 20-mm M61A1 rotary cannon
replaced the Genie nuclear-tipped missile in the internal weapons bay.