Convair F-106 Delta Dart

The Convair F-106 Delta Dart at a glance

The Convair F-106 Delta Dart was the U.S. Air Force’s primary all-weather interceptor through most of the Cold War. It had one job: find Soviet bombers at night or in cloud and destroy them before they reached North America.

It first flew on December 26, 1956, entered service in 1959 and left the Air National Guard in 1988. It remains the last specialist interceptor the Air Force has flown.

Pilots rarely called it the Delta Dart. In squadron service it was simply “The Six.”

Convair built 277 single-seat F-106As and 63 two-seat F-106Bs, and production ended in late 1960. No F-106 was ever exported, none ever fired a shot in combat, and none is flying today.

From F-102B to F-106: how the “Ultimate Interceptor” was born

The F-106 began life as the F-102B, a planned upgrade of the Convair F-102 Delta Dagger under the Air Force’s 1954 interceptor program. The F-102A had struggled to fly supersonic at all until its fuselage was reshaped to the area rule, and the Air Force wanted a true “ultimate interceptor” to follow it.

The F-102B was meant to use the Wright J67, a licensed Bristol Olympus. When that engine fell a year behind schedule, the Air Force switched to the bigger Pratt & Whitney J75 in early 1955.

The new engine forced so many changes that the aircraft was redesignated the F-106A on June 17, 1956. It got enlarged, variable-geometry air inlets, a longer and cleaner fuselage, a slightly bigger wing and a redesigned tail.

Convair test pilot Richard L. Johnson made the first flight at Edwards Air Force Base on December 26, 1956. The early results disappointed: acceleration and top speed fell short of Convair’s own estimates, and both the engine and the avionics proved unreliable.

The program nearly died. Air Defense Command fought for it, fixes to the inlets were found, and the Air Force pressed on, but it bought only about a third of the 1,000 aircraft once planned.

F-102 vs F-106: what actually changed

The two deltas look alike, which is why their names get mixed up. Under the skin they are different aircraft.

The F-106 swapped the F-102’s J57 for the far more powerful J75, with enlarged intakes and a variable-geometry inlet duct tuned for a wide range of supersonic speeds. It also got a longer, cleaner fuselage, a slightly larger wing and a redesigned vertical tail.

The bigger difference was performance and equipment. The F-102A had needed its fuselage reshaped just to go supersonic, while the F-106 reached Mach 2.3 and carried the Hughes MA-1 fire-control system the F-102 had been meant to get.

An interceptor flown by its radar

The F-106 was designed around the Hughes MA-1, an integrated weapon control system that linked the fighter to the ground-based Semi-Automatic Ground Environment (SAGE) radar network. Ground controllers could steer the aircraft to its target over a data link.

According to the National Museum of the U.S. Air Force, the MA-1 could take control after takeoff, fly the jet to the right altitude and attack position, fire its missiles, break off and bring it back toward base. The pilot took over again to land.

The system was ambitious and temperamental. The Air Force’s official history describes it as some 170 “black boxes” weighing about 1,800 pounds (816 kg), and it was modified more than 60 times in service.

Early F-106 ejection seats were a weak point. The first seats were not designed for zero-altitude, zero-speed escapes, some ejections ended in fatalities, and a Weber zero-zero seat was retrofitted across the fleet after 1965.

F-106 armament: missiles, a nuclear rocket and a gun added later

Like the F-102, the F-106 was designed with no gun and no provision for bombs. Everything it carried rode inside an internal weapons bay, which kept the airframe clean for supersonic flight.

The standard load was four Hughes AIM-4 Falcon air-to-air missiles, radar-guided or infrared, plus one AIR-2 Genie. The Genie was an unguided rocket with a 1.5-kiloton nuclear warhead, meant to be fired into a formation of bombers.

Did the F-106 have a gun? Not at first. Vietnam showed that missile-only fighters needed a cannon, and from 1972 the Project Six Shooter upgrade added provision for a 20 mm M61 Vulcan with 650 rounds in the center of the weapons bay, in place of the Genie.

The same upgrade brought a frameless canopy that greatly improved the pilot’s view, plus an optical gunsight. Many aircraft received the gun, but many kept flying operationally with the Genie.

How fast was the F-106? The 1959 world speed record

The F-106’s top speed is Mach 2.3 at 40,000 feet, the 1,325 kt · 1,525 mph · 2,454 km/h shown in the specification table on this page.

On December 15, 1959, Joseph W. Rogers flew an F-106A at Edwards Air Force Base to a world speed record of 1,525.695 mph over an 11-mile course, at about 40,500 ft. That beat the 1,483.84 mph Soviet mark set in the E-66, a MiG-21 relative.

The Aerospace Museum of California still bills the F-106 as the fastest single-engine fighter in the world on the strength of that run. Its speed is the reason it features among the fastest fighter jets of its generation.

Explaining the numbers

The full specification table for the F-106A is on this page. A few of its figures need context, because sources quote them against each other.

Range. The 2,346 nm · 2,700 mi · 4,340 km in the table is ferry range with the two external tanks, flown at 530 knots and 41,000 feet. On internal fuel alone the combat range is 1,335 nm, and the Air Force’s own data gives a combat radius of 633 nm with external tanks.

Climb. The table’s 39,800 ft/min · 202 m/s is the Air Force’s sea-level figure for a lightly loaded point interceptor. Many references print 29,000 ft/min instead, and quote a climb to 52,000 ft in six minutes and 54 seconds.

Ceiling. The 57,000 ft · 17,400 m service ceiling in the table is the figure most references use. The museum fact sheet gives 53,000 ft, while the Air Force’s technical data lists a 62,000 ft combat ceiling.

Approach speed. The table’s 175 kt · 201 mph · 324 km/h is the flight manual’s minimum final approach speed with 2,000 pounds of fuel left. The manual’s minimum touchdown speed at the same weight is 143 knots, and the landing checklist calls for the drag chute at touchdown.

Operational history: the interceptor that never saw combat

The F-106 guarded the continental United States, Alaska and Iceland, with brief deployments to Germany and South Korea. During the 1968 Pueblo crisis, F-106s from McChord Air Force Base deployed to Korea, refueling in flight for the first time on the way.

It was considered for Vietnam but never sent. In the 1960s the Air Force flew it against the Navy’s F4H-1 Phantom in a flyoff called Operation Highspeed, and the F-4 Phantom II won.

The F-106 stayed on anyway, because every Phantom was needed elsewhere. In mock combat it earned a strong reputation, with better high-altitude turning and a higher top speed than the F-4, and pilots reported beating both Phantoms and F-104 Starfighters in exercises.

From 1981 the F-15 Eagle began replacing it, and the surviving jets passed to Air National Guard squadrons. The New Jersey Guard’s 119th Fighter Interceptor Squadron flew the last of them and sent its final aircraft to storage in August 1988.

F-106 variants

F-106A. The single-seat interceptor and the version described by this page’s specifications. Many later received a conically cambered wing, supersonic external tanks, an in-flight refueling receptacle and an infrared search and track sensor.

F-106B. A tandem two-seat trainer that kept the full combat capability. It first flew on April 9, 1958, and 63 were built.

NF-106B. Two F-106Bs used by NASA and associated research facilities as test aircraft between 1966 and 1991.

F-106C/D, F-106X and F-106E/F. Unbuilt developments with bigger radars and longer noses. The C/D was canceled in September 1958, and the later F-106X and F-106E/F proposals never went beyond paper.

QF-106A. Retired airframes converted into target drones that could still be flown by a pilot for ferry flights.

The Cornfield Bomber: the F-106 that landed itself

On February 2, 1970, an F-106A on a training mission from Malmstrom Air Force Base entered a flat spin over Montana. Its pilot, Captain Gary Foust, followed procedure and ejected.

The change in balance from the ejection let the empty jet recover on its own. It then belly-landed in a snow-covered field near Big Sandy with only minor damage.

The aircraft, serial 58-0787, went back to base by rail, was repaired and returned to service. It last flew with the 49th Fighter Interceptor Squadron and has been on display at the National Museum of the U.S. Air Force since August 1986.

Retirement, target drones and NASA

Between 1983 and 1988 the F-106 fleet was flown to the military storage center at Davis-Monthan Air Force Base in Arizona. Starting in 1986, 194 of them were converted into QF-106A target drones under the Pacer Six program.

The last QF-106 shot down fell at Holloman Air Force Base on February 20, 1997, and the program ended in 1998.

NASA kept F-106s for research. An F-106B at Langley Research Center was deliberately flown into thunderstorms between 1980 and 1986 and was struck by lightning 714 times without damage, including 72 strikes during one hour at 38,000 ft in 1984. The research flights went into the clouds at about 300 knots.

NASA’s Eclipse project in 1997 and 1998 towed a QF-106 into the air behind a C-141A Starlifter to test a tow-launch concept for reusable launch vehicles. On May 1, 1998, the last flyable F-106 flew from Edwards to storage in Arizona.

Where to see an F-106 today

There are no flyable F-106s left, and the F-106 Delta Dart history site reports that every survivor has been demilitarized. Most sit on static display at museums and air bases across the United States.

The best-known is the Cornfield Bomber at the National Museum of the U.S. Air Force in Dayton, Ohio. Others include F-106As at the Hill Aerospace Museum in Utah, the Pima Air & Space Museum in Tucson, the Evergreen Aviation & Space Museum in Oregon and the Aerospace Museum of California in Sacramento.

Two-seat F-106Bs are on display at the Palm Springs Air Museum and the Yanks Air Museum in California. For how the Six fits into the wider family of American jets, see our guide to the types of U.S. fighter jets.

Frequently Asked Questions

Are there any F-106s still flying?

No. The last flyable F-106 flew to storage on May 1, 1998, after NASA’s Eclipse project. Every surviving airframe has been demilitarized and is on static display.

Did the F-106 ever see combat?

No. The F-106 was considered for the Vietnam War but never deployed there, and it was never exported, so it never fired a weapon in combat.

What was the difference between the F-102 and the F-106?

The F-106 began as the F-102B but gained the more powerful J75 engine, a variable-geometry inlet, a longer fuselage, a redesigned tail and the Hughes MA-1 fire-control system. It reached Mach 2.3, far faster than the F-102.

Did the F-106 have a gun?

Not originally. It was designed as a missile-only interceptor, and the Project Six Shooter upgrade of the early 1970s added provision for a 20 mm M61 Vulcan cannon in the weapons bay.

What was the top speed of the F-106?

Mach 2.3, or 1,325 kt · 1,525 mph · 2,454 km/h at 40,000 feet. An F-106A set a world speed record of 1,525.695 mph on December 15, 1959.

How many F-106s were built?

Convair built 277 F-106As and 63 two-seat F-106Bs, a total of 340, and production ended in late 1960.

Why was the F-106 called “The Six”?

In service the F-106 was universally known simply as “The Six,” and its official name, Delta Dart, was rarely used.

How much did an F-106 cost?

The Air Force’s official history puts the flyaway cost of each production F-106A at $4.7 million in production-era dollars. Nearly half of that was electronics and armament rather than airframe.