is intercepted by a F-106A off
Cape Cod in 1982 Early operations of the F-106 were troubled by numerous technical issues. These included generator defects, fuel-flow issues (particularly during cold weather), and combustor-starter malfunctions. During December 1959, all F-106s were temporarily grounded following the accidental jettisoning of the canopy mid-flight on one aircraft. Many, but not all, of these problems were resolved by the start of 1961; this can be partially attributed to two major modification and retrofit program conducted during this timeframe. Following the resolution of initial teething problems – in particular an ejection seat that killed the first 12 pilots to eject from the aircraft – its exceptional performance led to the aircraft becoming relatively popular amongst its pilots. The F-106 served in the contiguous US, Alaska, and Iceland, as well as for brief periods in Germany and South Korea. The F-106 was the second highest sequentially numbered P/F- aircraft to enter service under the old number sequence (the
F-111 was highest), before the system was reset under the
1962 United States Tri-Service aircraft designation system. In service, the F-106's official name, "Delta Dart," was rarely used, and the aircraft was universally known simply as "The Six." The arrival of the F-106 in quantity quickly led to the withdrawal of various older aircraft that were being used in the interceptor role, such as the
North American F-86 Sabre and the
Northrop F-89 Scorpion. Although contemplated for use in the
Vietnam War, the F-106 never saw combat, nor was it exported to foreign users. After the cancellation of their own
Avro Arrow, the Canadian government briefly considered purchasing the F-106C/D. To standardize aircraft types, the USAF was directed to conduct Operation Highspeed, a flyoff competition between the USAF F-106A and the U.S. Navy F4H-1 (F-4B) Phantom, which was not only as capable as the F-106 as a missile-armed interceptor but could carry as large a bomb load as the
Republic F-105 Thunderchief fighter-bomber. The Phantom was the winner but would first be used to escort and later replace the F-105 fighter-bomber in the late 1960s before replacing older interceptors in Air Defense Command in the 1970s. , SC in 1982 The F-106 was progressively updated in service, with improved
avionics, a modified wing featuring a noticeable conical camber, an
infrared search and track (IRST) system, streamlined supersonic wing tanks which provided virtually no degradation to overall aircraft performance, better instrumentation and features like an
inflight refuelling receptacle and an
arrestor hook for landing emergencies. Air-to-air combat testing suggested "The Six" was a reasonable match for the F-4 Phantom II in a dogfight, with superior high-altitude turn performance, overall maneuverability (aided by the aircraft's lower
wing loading) and a higher top speed. While the twin-engine F-4 had much better acceleration, it had a lower top speed than the F-106, which could usually catch up and overtake it. The Phantom had better radar – operated by an additional crewman – and could carry a load of up to four radar-guided
AIM-7 Sparrow and four infrared
AIM-9 Sidewinder missiles, while the AIM-4 Falcon missiles carried by the F-106 proved a disappointment for dogfighting over Vietnam. The F-4 had a higher thrust/weight ratio with superior climb, better high speed/low-altitude maneuverability and could be used as a fighter-bomber. Air combat experience over Vietnam showed the need for increased pilot visibility and the utility of a built-in gun, which had been added to the "E" variant of USAF Phantoms. d fuselage In 1972, some F-106As were upgraded in Project Six Shooter that involved fitting the F-106 with a new canopy without metal bracing which greatly improved pilot visibility, an optical gunsight and provision for a
M61 Vulcan 20 mm
cannon, replacing the
AIR-2 Genie and its nuclear warhead. The M61 Vulcan was mounted in the center of the weapons bay, had 650 rounds of ammunition. While all F-106A model aircraft received the Six-Shooter modifications, and many of them received guns, most continued to fly operationally with the AIR-2. In intra-USAF exercises against both
Lockheed F-104 Starfighter and F-4 units, F-106 pilots were reportedly victorious on many occasions. The F-15A Eagle started replacing the F-106 for some units in 1981, with "Sixes" typically passed on to
Air National Guard units. The F-106 remained in service in various USAF and ANG units until 1988. When the need for a high performance Full Scaled Aerial Target Drone was required, the USAF began withdrawing Delta Darts from storage. Starting in 1986, 194 of the surviving surplus aircraft were converted into
target drones and these were designated
QF-106As and used for target practice vehicles under the
Pacer Six Program by the
Aerial Targets Squadron. The last was destroyed in January 1998. The QF-106 replaced the QF-100
Super Sabre drone; the last shoot down of a QF-106 (57-2524) took place at Holloman AFB on 20 February 1997 after which the QF-106 was superseded by the QF-4S and QF-4E Phantom II drone.
NASA research and test aircraft Six F-106s were retained by
NASA for test purposes through 1998. An F-106B two-seat trainer was operated by NASA
Langley Research Center between 1979 and 1991. This Delta Dart was used in research programs ranging from testing supersonic engines to improving maneuverability of fighters. Between 1980 and 1986 the aircraft was modified for the purpose of lightning strike research and became known as the
Lightning Strike Plane and was struck 714 times without damage. On one hour-long flight at in 1984, lightning struck the research aircraft 72 times. One significant modification was the replacement of the composite nose radome by a metallic radome. Although the maximum speed of the F-106 was Mach 2.3, during the lightning experiments it was flown at subsonic speeds into clouds at from . The aircraft was equipped with optical sensors which consisted of a video camera and a light detector. Data acquisition was performed with 1980s state of the art
digital waveform recorders.
Eclipse project NASA used six drones in its
Eclipse Project which ran from 1997 to 1998. The
Dryden Flight Research Center supported project Eclipse which sought to demonstrate the feasibility of a reusable Aerotow-
launch vehicle. The objective was to tow, inflight, a modified
QF-106 aircraft with a
C-141A transport aircraft. The test demonstrated the possibility of towing and launching a space launch vehicle from behind a tow plane.
The Cornfield Bomber On 2 February 1970, an F-106 of the
71st Fighter-Interceptor Squadron, piloted by Captain Gary Foust, entered a
flat spin over
Montana. Foust followed procedures and ejected from the aircraft. The resulting change of balance caused the aircraft to stabilize and later
belly land in a snow-covered field, suffering only minor damage. The aircraft, promptly nicknamed "The Cornfield Bomber", was then sent back to base by rail, repaired and returned to service, and is now on display at the
National Museum of the United States Air Force. ==Variants==