The Convair F-106 Delta Dart was a supersonic, all-weather delta wing interceptor aircraft of the United States Air Force from the 1960s through 1988. Referred to as the "Ultimate Interceptor"
it was the last dedicated interceptor in USAF to date. Originally envisioned as an advanced derivative of the F-102A Delta Dagger and given the designation F-102B, the "Ultimate
Interceptor", as it was known, entailed such extensive changes that in June, 1956, the designation was changed to F-106. It was designed from the ground up as an Interceptor and nothing but an
interceptor. Originally designated the F-102B, it was re-designated the F-106 due to it's extensive structural changes and the more powerful Pratt & Whitney J75 engine
The single seat F-106A first flew on December 26, 1956, was delivered to and entered operational service with the US Air Force (USAF) in May 1959 and achieved initial operational capability in October,
1959. The two-seat F-106B made its maiden flight on April 9, 1958, achieved initial operational capability in July 1960, and retained the full combat capability of the F-106A. All F-106 production
ended in late 1960 with a total of 277 F-106A's and 63 F-106B's being built at a cost of about $5 million each.
The F-106 Delta Dart was manufactured by the Convair Division of General Dynamics. It's design, and
that of its predecessor the F-102A,
is closely linked to Langley and the development of "area ruling"
(Area Rule) in the early 1950's. Area Rule
reduces drag at transonic speeds and is reflected in the "coke bottle" or "wasp waist" shaped fuselage of the F-106. Area ruling enabled the YF-102A to easily exceed the speed of sound and
subsequently led to the go-ahead for the advanced version which became the F-106. The significance of area ruling was recognized by the National Aeronautic Association which awarded the originator, Richard T.
Whitcomb, its prestigious Collier Trophy for the greatest achievement in aeronautics in 1955. It was powered by a single Pratt and Whitney J75-P-17 turbojet engine of 16,100 LB thrust
(24,500 LB thrust with afterburning).
Developed as an interceptor, its mission was to shoot down other aircraft, bombers in particular. It used a Hughes MA-1 electronic guidance and fire control system. As quoted to me in an e-mail by
Dick Stultz, LtCol, USAF (Ret) who was an F-106 Pilot and who "Fired simulated AIR2A in William Tell Competition without Operational MA-1"
"The MA-1 NEVER had full control of the aircraft,
a capability so many publications erroneously extol. The MA-1, using its data link target information or command information, would provide directives for altitude, airspeed, xyz coordinates and command directions,
which would be flown by the autopilot, however, the MA-1 NEVER regulated the throttle at any time, for forward and aft movement, thus the MA-1 could never really fully control the airplane except to provide
requested directions that required coupling and thrust selection by the pilot. The pilot HAD to take it off, climb, descend, and land the aircraft, every time!" The F-106 proved its ultimate performance
capabilities in providing aggressor "enemy" delta-wing familiarization training to the Navy's best pilots during the time they were implementing TOP GUN. The Navy jocks learned valuable lessons that the
Delta winged 106 was almost unconquerable in the dogfight arena, with guns in the air-to-air environment, which you read so little about in the Navy publications. Wing loading of 43 lbs/sq ft and a .8 -1 TWT
put it in a class of its own against the A4s, F-104s, F4B,C,D, F-105, F-100, F8 fighters of its time.....not to mention the many many '14s and '15s that blew engines in attempting to fight when it took them
above 40,000 feet, to a guns-only environment. Good thing they finally fixed those great fighters to handle the altitudes the 106s formerly ruled.
The F-106 also came in a 2 seat "B". Unlike other popular 2 seat aircraft, such as the F-4, the back seater in the "SIX" had the exact same control capability as the front seater. He could
fly the aircraft and perform all operations from his rear seat. The F-106B also could carry the same armament.
On December 15, 1959, Colonel Joe Rogers piloted an F-106A to a World Speed Record of 1,525.695 mph (Mach 2.41). The F-106 still holds the record as the fastest single-engine turbojet-powered airplane.
The F-106 served with the USAF Air Defense Command (ADC), Tactical Air Command (TAC), and Air National Guard (ANG). The Air Force gradually retired the aircraft from active service after a long and distinguished
career during the 1980s, last unit in 1988. The post Delta Dart period saw them used as drone targets during air-to-air missile training for our current generation of fighter aircraftThe with the QF-106 drone
conversions being used until 1998 under the Pacer Six Program. The Six also saw continued use with many NASA projects. While there are no flyable F-106's remaining, all survivors have been de-milled with
most survivors on static display in museums and parks
Note By Mark Foxwell, Col, USAF (Ret), Commander, USAF IWS
from 1 Feb 2015
"I flew several sorties in the F-106 in a full pressure suit... while we were developing new High Altitude Intercept Tactics at IWS. I had the Six above 75,000 ft."
CONVAIR WINS DELTA WING DESIGN CONTRACT
On 11 September 1951, Convair received a contract for its delta wing design, designated the F-102. Work on the competing Republic design was also authorized, and was designated XF-103,
however, the XF-103 was so far ahead of the state of the art, it was deemed too risky to be a serious contender for the 1954 Interceptor project. This made the F-102 for all practical
purposes the winner of the contest.
The USAF authorized fitting a Westinghouse J40 turbojet into the first few examples of the F-102, but production aircraft were to be powered by the 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
"Cook-Craigie" Program to Expedite 1954 Interceptor Development
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, who during the late 1940s developed a concept of an aircraft
development program where the usual prototype stage would be skipped. Rather than waiting to start full-scale production until the prototypes had passed flight
testing and the bugs ironed out, the Cook-Craigie plan called for delivery of a small number of production aircraft during the flight testing
phase so 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, as it can produce a new combat aircraft in a hurry if everything goes right during flight testing, but can
result in costly and time consuming fixes in the field if unexpected problems turn up. The Cook-Cragie plan is viable if there's a high
degree of confidence that the aircraft is really going to go into production, and since the F-102 was basically a scaled-up XF-92A, the risk seemed worth taking.
From the F-102A F-102B F-106
By December of 1951, it was apparent the Wright J67 engine and the MA-1 fire-control system would not be ready in time, which forced the USAF to change its plans. They 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 later on. The interim version was designated F-102A, and the fully-developed advanced version designated F-102B. The F-102A would use the less-powerful Pratt & Whitney J57 turbojet, but the F-102B
would retain the high-thrust J67. The F-102A would be equipped with an interim fire-control system, but the F-102B would be equipped with the highly-sophisticated Hughes fire control system under project
Although the F-102A was considered only an interim version pending availability of the F-102B, it ran into some unexpected developmental difficulties and fell behind schedule. A lot of money
originally planned for the F-102B, now had to be diverted into fixing F-102A 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 known as the MA-1) was slipping badly. 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, and the
Air Force needed to consider alternative powerplants, finally settling on the Pratt & Whitney J75, which was an advanced version of the J57 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, with their serials ranging from 56-0451 t0 56-0467
. The F-102B mockup was ready for inspection in December
of 1955. On 18 April 1956, the Air Force finalized the F-102B production contract of the previous November, ear-marking all 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.
Buzz Number Codes
The first 3 F-106's, 56-0451, 56-0452 and 56-0453, were initially designated as F-102B and carried a buzz number designator as 'FC' since the F-102
designator was 'FC'.
When the aircraft was redesignated as the F-106 it was given a buzz number designator of 'FE'. The buzz number designator would be painted on the
fuselage, which stopped sometime in the late 1960's.
On 17 June 1956, the F-102B designation was
changed to F-106A
, which was in affect an official 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 due
to so many aerodynamic changes and
far more advances to include a variable-geometry inlet design.
In September of 1956, the Air Force specified that the
F-106A would be available by August 1958, four years later than
initially planned, and it had to be compatible with the
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, and would 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, which were replaced in FY 1957 with leading edge slots. The
"wet" wing used no fuel bladders, and fuel
transfer was accomplished using low pressure bleed-air
from engine into the tanks. It was thought, however combat damage, even
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 and a "coke-bottle" design. The variable-ramp air intakes were moved well
aft of the nose and mounted closer to the engine, and the shape of the fin and
rudder were changed with a clamshell-type airbrake fitted at the base of the
A new undercarriage was fitted with steerable twin-nose
On the first F-106s, the upper and lower rotating
navigation beacon lights retracted when the aircraft went supersonic. They
were located immediately aft of the canopy in the dorsal
position and immediately behind the nose wheel on the belly of the aircraft, but
the retractable feature was
disabled in later years.
The Pratt & Whitney J75 twin-spool, axial-flow
afterburning turbojet was the same engine which powered the Republic F-105 Thunderchief, and was rated at 15,000 lbs thrust dry, and 23,500 lbs thrust in
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
Electronics Package, WS-201A System - Project MX-1179
The electronics package of the projects design came first, known as the new WS-201A system. Project MX-1179 was the designation given to the 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, with the Hughes proposal consisting of an 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.
Airframe - MX-1554 Project
The airframe portion of the project was designated MX-1554. Proposals were requested by the Air Force on June 18, 1950, and 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
- Single proposals were made by
Chance-Vought, Douglas, Lockheed, and Convair.
On July 2, 1951, the Air Force announced designs by Convair, Lockheed, and Republic had been selected to proceed with preliminary development. All three were to proceed with their designs all the way
to the mockup stage, with the design deemed most promising being awarded a production contract. Later, the USAF deemed it too costly to carry through with three concurrent development programs,
so it cancelled the Lockheed project entirely. The Convair and Republic entries were given the go-ahead to proceed. Republic's entry bore the company designation of AP-57 (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. Convair's entry was closely related to the experimental XF-92A, which Convair 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 consultation with Dr. Alexander Lippisch, who had done pioneering work in Germany on delta wing 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 wing
aircraft to fly, but the F-92 project had itself been cancelled before any prototype could be built.
First F-106A Flight
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 as 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 26 February 1957. They were both powered by the YJ75-P-1 engine.
Serial number 56-0451, the first F-106 (F-106A) produced by Convair at San Diego CA,
on 14 Dec 1956 was trucked from Convair to AFFTC Edwards AFB CA. On 22 Dec 1956 it began Taxi tests. On 26 Dec 1956 it made its first flight
which included an air abort due to air turbine motor frequency fluctuations and
speed boards that opened and wouldn't close. This first take-off was performed without afterburner, which was comperable to an F-102 Delta
Dagger take-off 'with' afterburner. The 20 minute flight took the
aircraft to an altitude of 30,000 miles and 0.8 Mach.F-106B:
Serial number 57-2507 was the first F-106B produced by
Convair, which was also trucked from Convair to AFFTC Edwards AFB CA. Taxi test runs were completed on 8 April 1958. The first B model flight was
made on 10 April 1958
piloted by pilot Fitzpatrick. The first flight lasted for 50 minutes, almost twice as long
as the F-106A first flight. The aircraft also reached higher altitudes and obtained faster supersonic speeds than is normal for a first flight. Your author here
can only imagine that was due largely but the fact the F-106A was already a tried and true model, which the 'B' models were so much like.
Armament and Engine
As on the F-102A, the all-missile armament was housed internally in a spacious ventral weapons bay, which 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 re-designated AIM-4E and AIM-4G respectively) air-to-air
missiles. The unguided 2.75-inch missile armament of the F-102A was omitted.
Missile Bay door
system operated on 3,000 psi air pressure to drive the doors open in 1.5 seconds and after the selected munitions are fired fired closed in 0.75 seconds.
A main Air Flask wwas charged to 3000 psi, and the weapon system actuators worked at 1500 psi via a regulator. The cycle time on the missile bay doors however, did vary with whatever weapon(s)
were being fired. The AIR-2A Genie was fastest because it was ejected from the bay (it took .23 seconds from ejection to forward motion); but could also fire either 2 AIM 4F radar missiles at a time
(could NOT fire just one missile) OR 2 AIM 4G IR missles; OR Both, which fired 2 IR missles from the back set of rails first (so the IR missles would not guide on the radar missiles). Then after those rails
retracted, the front set of AIM 4F radar missiles would extend, fire and retract, then the doors would close. There was also a "guts" button, as it was called, in the cockpit to close the doors if
the sequence got screwed up and
the doors didn't close automatically. HGavimng the doors remain open might cause STRUCTURAL DAMAGE if the rails hadn't retracted. The "guts" button would be used only with visual confirmation from
another plane as to whether or not the rails were still extended.
An operations test of the entire process by maintenacne crews called a "Trigger Salvo" was quite an experiance to behold... and hear, especially for the maintenacne troop up in the Nose Wheel Well holding
the gear positon switch, which simulater the gear being up (required to launch missles). This was a common test during Phase Inspections.
The Air-2A Genie rocket
was carried in the rear half of the missile bay. It was powered by a 36,600 lbs thrust 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 Genie rocket was ejected from the weapons bay by gas pressure generated when 5 impulse cartridges fired on the special weapons
rack, kicking the rocket down and away from the aircraft. There were 2 lanyards attached to the rocket from the special weapons rack that when pulled out of the Genie which would ignite the solid fuel motor.
The AIM-4 Falcon missiles
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 and made its first flight on December 26, 1956. The second aircraft (56-0452) followed on
26 February 1957. The first two aircraft were not equipped with the MA-1 system, carrying nose ballast to compensate for the missing weight.
The test and development work on the F-106 was divided into six phases. Phase I was conducted by the contractor, and Phase II was conducted
by the Air Force. Phase II tests were 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.
Initial Speed and Acceleration Problems
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, rated at 17,200 lbs thrust dry
and 24,500 lbs thrust in 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 equipped 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 (IID), was made standard starting with aircraft 58-0759.
Some of the early aircraft were subsequently upgraded with IID, but many never
got the vertical tapes.
Initial aircraft had wing 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
In mid-1957, the F-106A was given the popular name
Originally, the Air Force had planned to acquire 1000
Delta Darts to equip forty plus Air Defense Command (ADC) squadrons.
However, by 1957 the delays in the F-106 program and the problems with the
engine and fire control system had resulted in the necessity of a stop-gap
measure of ordering other
interceptors such as the McDonnell F-101B Voodoo, and the F-106 lost some of its urgent priority. For a
while, serious consideration was given to canceling the entire F-106 program,
or else 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 260 more 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 30 May 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 at Geiger AFB in Washington. This was five years
later than originally planned, and even then, numerous problems kept the Delta Dart
from being declared fully operational until 31 October 1959. The remaining 13
squadrons were re-equipped with the F-106A by the end of 1960.
On 15 December 1959, 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, which beat the previous record of 1483.83 mph, set by Georgiy Mossolov in
a Soviet Ye-6/3 on 31 October that same 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.
MA-1 Fire Control System
Also see MA-1 and SAGE page
The MA-1 fire control system was
initially quite unreliable and was subjected to a lot of in-service modifications
in an attempt to fix its chronic problems. The MA-1 system was upgraded 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
(Semi-Automatic Ground Environment)
network 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 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.
In September of 1960, due to the numerous modifications to the MA-1 fire
control system made during production, a major modification project named "Wild
Goose" was initiated 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 roaming AMC field
assistance teams supported by ADC maintenance teams working at ADC bases.
The 277th and last F-106A was delivered on
20 July 1961.
The production run also included 63 F-106B two-seaters, for a total of 340
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
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 never intended for carrier-based operations.
The F-106 had to be grounded again on 26 September 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, however, was the revision
of the ejection system.
Ejection System Development
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's not clear what the B designation stood for, but pilots believed that it was so named because it resembled a bobsled. It was designed with supersonic ejection specifically in mind, and 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 James HowellNote 1
ejected safely from an F-106B piloted by Major James Hendrix on 6 June 1961.
The ejection sequence with the Convair 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. 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.
Note 1Technical Sergeant James Howell was a USAF Combat Controller on a Special Duty Assignment as a Test Parachutist located at El Centro, California.
He also was part of a joint Army, Air Force High Altitude Low Opening (HALO) world record. Source: William Howell, son of Technical Sergeant James Howell, as e-mailed to the webmaster 27 June 2009
M61A1 20-MM 'Six Shooter' Cannon
The F-106A surprised everyone by having good maneuverability and showing potential as being an excellent dogfighter. There were some thought to using the F-106 for top cover in Vietnam. Among suggestions were to apply tactical camouflage, fit a clear-view canopy, and add 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 altitude.
In support of the cannon armament program, Convair issued a proposal to re-equip the F-106 with an internal cannon, an optical gun-sight, and a clear-view cockpit canopy in a program known as Project Six 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 mounted inside the missile bay providing an aerodynamic shield for the portion of the gun protruding below the missile bay and out into the air stream. 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.The gun installation was first tested 10 February 1969 on F-106A 58-0795 and subsequently on 59-092. A prototype gun-sight 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, compared to 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 idea of painting the F-106 in camouflage scheme was abandoned, when it was found that there was no significant advantage in doing so seeing as the F-106 would never go to Vietnam.In the late 1960s, the F-106 was provided with newly-designed larger-capacity under-wing external fuel tanks, often called "supersonic tanks", since they could be carried underneath the wings at any speed. They were a 360 US-gallon capacity, 50 percent larger than the previous 227-gallon tanks, and were jettison able, although this was rarely used in practice. The tanks were routinely carried on all but the shortest-range intercepts.In conjunction with the new under-wing tanks, in-flight refueling capability was retrofitted to all surviving F-106s, by retrofitting a slipway receptacle in a dorsal position behind the pilot. The first refueling installations were installed in 1967.The F-106 served mainly in the continental United States, 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 combat.
F-106 Phase-out to the F-15
Beginning in 1972, the McDonnell Douglas F-15 Eagle gradually began replacing the Delta Dart in ADC squadrons. As they were removed
from Air Force active duty service, the F-106's were passed on to the Air National Guard.
The first ANG unit to receive the F-106 was the 186th FIS of the Montana ANG, based at
Great Falls, taking delivery of its first planes on 3 April 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 7 July 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 also the 119th FIS, 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-engine 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 Dart.
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 1982, and 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.
QF-106 Target Drone Program
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 shoot down 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.
Eclipse Tow Launch Project
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) using
a synthetic rope. The first flight was made on 20 December 1997, and the last
test took place on 6 February 1998. The tests were made to explore the
feasibility of having a Boeing 747 tow an RLV known as the Astroliner to 45,000
feet, where the Astroliner would fire its rocket engines and fly into orbit. On
1 May 1998, this last flyable F-106 flew from Edwards to AMARC.
F-106B Two-Seat Model
The F-106B (Model 8-27) was a two-seat combat trainer version
of the Delta Dart. 63 examples were ordered on 3 August 1956. The aircraft was
originally intended as a pure trainer and was initially designated TF-102B and
then later re-designated TF-106A. The designation F-106B was eventually chosen
when in late August of 1956 the Air Force specified that full combat capability
was to be provided for the two-seater.
To avoid the problems experienced with the side-by-side TF-102A trainer
version of the Delta Dagger, a tandem seating arrangement was chosen. The two
crew members sat under a large, single-piece clamshell- type canopy. The fitting
of the aft seat reduced the fuel capacity removing a fuel cell, and displaced some of the avionics to
the weapons bay. The external dimensions of the F-106B were exactly the same as
those of the F-106A. The F-106B was equipped with the Hughes
AN-ASQ-25 fire control system, which was equivalent to the MA-1 of the F-106A,
and had the same armament capability, which was a quartet of Falcon air-to-air missiles plus one Genie rocket equipped with a
nuclear warhead, all housed in the internal weapons bay.
Procurement of the F-106B was included in the third F-106A contract, but the
F-106B definitive contract was not finalized until 3 June 1957.
The first flight of the F-106B (57-2507) was made on
10 April 1958. The first
eight aircraft off the production line were temporarily designated JF-106B for
flight tests. The first delivery to the USAF was made in February of 1959, however, the F-106B suffered from the same development problems as the F-106A
single-seater, and was not declared fully operational until July of 1960.
The first 12 F-106Bs off the production line were initially allocated to
testing, but they were eventually brought up to the standards of the rest of the
F-106 fleet. The last F-106B aircraft were completed as Model 8-32s, with improved MA-1 fire
control systems, supersonic ejector seats, vertical instrument display panels,
Case 29 wings with revised camber, and with provision for 230-US gallon
Production of the F-106B ended in December of 1960 with the delivery of the last
The F-106B participated in all of the F-106A modification programs, since the
aircraft were so similar. Like the F-106A, the F-106B was initially powered by
the J75-P-9 turbojet later replaced by the more powerful J75-P-17. All
64 F-106Bs built received Convair's new supersonic ejector seats with two-stage
booms. The Convair supersonic seats were, however, replaced by Weber "zero-zero"
seats later in the 1960s, however, the F-106B never received the weapons bay
In the field, each ADC and ANG squadron was provided with several two seat "B"
models, which were used to perform combat proficiency training and checks. They
were fully capable of performing normal intercept missions.
F-106's with NASA
Two F-106Bs (57-2507 and 57-2516) were supplied to NASA for use as systems development aircraft. They were re-designated NF-106B and assigned the civilian
registration numbers N607NA and N616NA respectively.
F-106B 57-2516 arrived at Lewis Research Center in October of 1966 where it was assigned the NASA number 616. It was used for research and development in
support of supersonic transport engine inlet design. It was later modified with two additional jet engines mounted underneath the wings. 616 was transferred to
the Dryden Flight Research Facility at Edwards AFB in January of 1979, where it was renumbered 816. This plane was later loaned to Langley, where it was
modified by the Langley Research Center in 1979 to evaluate the effect of lightning strikes on aircraft. In 1988, it was fitted with Langley-designed and
manufactured wing leading-edge vortex flaps in connection with the Advanced Technology Fighter program. This aircraft was retired on 17 May 1991 and was the last
flight having been flown on 5 March from Langley AFB in Virginia. The aircraft is now display at the Virginia Air and SpaceCenter at Hampton.
In March of 1981, F-106A serial number 59-0123 was transferred to NASA at Langley to serve as a spare for 816.
F-106B 57-2507 arrived at Lewis in September of 1972, where it was assigned the
number 607. It was used for solar cell and ocean color scanning tests, which were designed to be used in water and land quality evaluation. In May of 1981,
607 was transferred to Langley. It was cut in half in 1984 for use in full-scale wind tunnel testing.
F-106B 59-2545 arrived at Langley on 30 January 1985, and is a non-flyable aircraft used for various tests.
F-106B number 57-2513 was used as a Rockwell B-1 chase aircraft by the San Antonio Air Logistics Center at Kelly AFB in Texas.
The F-106X (Model 8-28/8-29)
was a 1956 design study for a Delta Dart follow-on. With the XF-108 effectively dead, Convair attempted to modernize the F-106 design.
This study envisaged an interceptor with a canard layout that was
powered by a JT4B-22 turbojet fed by rectangular air intakes. It was envisaged as an alternative to the Lockheed YF-12 (later SR-71), and was to have had a
fire control system with "look-down, shoot-down" capability fed by a 40-inch radar dish. The F-106X was extremely advanced for its time with Mach 5 performance envisaged by Convair.
Carried over from the F-106, the only thing would have been the basic delta design. A more powerful engine was to be mounted with redesigned intakes to account for the new engine. Canards were added on the
intakes and the cockpit was raised to improve visibility. The fire control systems were to be given a complete overhaul with the AN/ASG-18 previousy developed for the XF-108.
The project was later re-designated F-106C/D, with "C" being the single-seat version, the "D" being the two-seat version. At one time the Air Force had
considered acquiring 350 of these advanced interceptors, but the F-106C/D project was cancelled on 23 September 1958. Convair got as far as mounting a new nose on an F-106 to test the practicality of the
design before the project was cancelled.
Following the cancellation of the Model 8-28/29 project, two production F-106A's;
57-0239 and 57-0240
, were modified to test the new radar housing with a
five-foot nose extension. They were re-designated F-106C
. Only 57-0239 actually flew, and made ten flights with this new nose in 1959. The plane was later
destroyed in fatigue tests. 57-0240 eventually reverted to standard F-106A configuration.
On 9 February 1968, the Defense Department announced they were not going to purchase the Lockheed F-12A interceptor (later the SR-71), opting instead to remain with the F-106 as the primary interceptor
to protect the continental USA from air attack.
On 3 September 1968, Convair issued a proposal for an "improved" interceptor that was to be designated F-106E/F. It was to be compatible with the upcoming airborne warning and control systems
as well as with the over the horizon radar defense network. The F-106E/F would have had a longer lose, with a new and improved radar with a "look-down/shoot-down" tracking and missile launch
capability. It would also have had a two-way UHF voice and datalink radio. It would be capable of launching both nuclear and non-nuclear missiles, including the AIM-26 Nuclear Falcon and the AIM-47.
Unfortunately for Convair, this project never got off the drawing board.
The Delta Dart was never exported to foreign air forces. A pair of F-106's were displayed at the 25th Paris Air Show in June of 1963, but no customers were forthcoming. Convair
tried to interest Canada in a Canadian version-not merely as in interceptor but also for the strike role. Nothing ever came of this idea. There were also
plans for F-106 final assembly and production in Germany, but these plans never reached fruition. There was a proposal for an F-106 version for Japan
with an MG-10 fire control system (the same one that was fitted to the F-102A Delta Dagger) and six Super Falcon missiles. It was also to have ground-attack
capability, with a pair of pylons underneath each wing capable of carrying bombs or fuel tanks. The Japanese sale never took place and several years later Japan undertook manufacture of the F-4EJ Phantom.
The F-106 Delta Dart served primarily in the continental United States, in Alaska and in Canada, and while never permenantly assigned to any overseas location,
did serve short TDY spells, deployments and special appearances around the world. The the Delta Dart however, never saw any combat.
- Korea: Several F-106 FIS units deployed to sit Alert at Osan AB, South Korea as part of the Korean buildup to support two distinct actions of
the USS Pueblo'
and EC-121 Shoot-down incidents. They sat Alert following the USS Pueblo incident and to fly shotgun for the EC-121 Constellation's after one got shot down by North Korea on 15 Apr 1969.
The first F-106's deployed from the 318th FIS McChord AFB on 22 Mar 1968, conducting in flight refueling en route, the first such refueling of F-106's. The last unit to serve in Korea was the
95th FIS which departed Korea on 1 May 1970. In between those dates (and units) also served the 48th, 71st and 94th FIS'.
- Germany: September 1975, 5th FIS deployed 7 F-106's tail numbers F-106A 56-0460, 59-0005, 59-0010, 59-0015, 59-0019, 59-0063, F106B 58-0901 to Hahn
AB, Germany (Europe) to participate in the NATO exercise Autumn Forge/Cold Fire '75, 4 to 27 September 1975.
- Iceland: The 87th FIS Red Bulls deployed to Keflavik Iceland in April 1978 to assisted the 57th FIS with Alert Duties as that unit transitioned
from F-4Cs to F-4Es.
- France: Two F-106's deployed from the 48th FIS for displayd at the 25th Paris Air Show, June 1963.
F-106A 59-0136 was on display, while F-106A 59-0124 was the spare.
- Panama: Spring 1974, 318th FIS deployed F-106's to Howard AFB in the Panama Canal Zone for Exercise Blackhawk '74
- History of the Convair F-106 Delta Dart, Joe Baugher Research
- General Dynamics Aircraft and their Predecessors, John Wegg, Naval Institute Press, 1990
- The Illustrated Encyclopedia of Aircraft Armament, Bill Gunston, Orion, 1988
- United States Military Aircraft Since 1909, Gordon Swanborough and Peter M. Bowers, Smithsonian, 1989
- The American Fighter, Enzo Angelucci and Peter Bowers, Orion, 1987
- Fighters of the United States Air Force, Robert F. Dorr and David Donald, Temple Press Aerospace, 1990
- American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday, 1982
- Post-World War II Fighters, 1945-1973, Marcelle Size Knaack, Office of Air Force History, 1986
- The World Guide to Combat Planes, William Green, MacDonald, London, 1966
- The World's Fighting Planes, William Green, Doubleday, 1964
- The Aircraft of the World, William Green and Gerald Pollinger, Doubleday, 1965
- F-102 Delta Dagger, Benoit Colin, Combat Aircraft, Vol 1 No 3, September 1997