Drone converted F-86s and F-100s

The operational histories of the F-86 Sabre and F-100 Super Sabre jet fighters have been well-documented in the literature with emphasis on not just their wartime combat careers but also operational use by foreign air arms around the world, including US allies. However, lost in talk regarding the F-86 and F-100 is the fact that these iconic jet fighters were also specially used as drones to give pilots and Army personnel experience against real aerial targets after the US Air Force retired the F-86 and F-100 from active combat duty.

The first QF-86E prototype (civil registration N74170) in Mojave, California, after completing its first flight in May 1975. This aircraft was built under license by Canadair as a Sabre Mk. 5 with RCAF serial number 23320. 

In 1973, while attending a Targets Conference at Point Mugu, California, Bob Laidlaw, a graduate from the Massachusetts Institute of Technology (MIT) with an advanced degree in Aeronautical Engineering and the founder of the Newport Beach-based company Flight Systems Inc. (FSI), investigated the idea of modifying vintage F-86 Sabre jet fighters into pilotless drone targets. In December, FSI submitted an initial proposal for a drone-converted F-86 to the US Army Target Branch in Huntsville, Alabama, and a contract was immediately signed for development of a proof-of-concept F-86 target drone. Laidlaw secured a purchase option on a lot of 55 ex-Royal Canadian Air Force Canadair Sabre Mk. 5 aircraft owned by Dave McEwen, a native of Moncton in New Brunsvick, Canada, and in 1974 one Sabre Mk. 5 (RCAF 23320) was acquired by FSI from McEwen to be modified into a proof-of-concept Sabre drone, and it received the civil registration N74170 after arriving at Mojave. In June 1974, another ex-RCAF Sabre Mk. 5 (RCAF 23096) which had been used by Boeing as a chase plane for airliner test flights and bore the civil registration N8686F while in that role until its replacement by a Sabre Mk. 5 with Sabre Mk. 6 wings (ex-RCAF 23363) was acquired by FSI and ferried from Seattle to Mojave, receiving civil registration N74180 and becoming the second Sabre drone prototype. The designation QF-86E was assigned to these two Sabre Mk. 5s, and in February 1975, FSI personnel began modifying N74170 with remote flight control systems while creating as very little modification to the basic airframe of the aircraft as possible, and after being fitted with these systems, N74170 made its first flight in April, when conversion of N74180 to a target drone began. In May-June 1975, the QF-86E prototypes were transferred to Holloman AFB in New Mexico for range integration testing, and after the two aircraft completed 60 flight hours of full-scale target presentations, the US Army awarded FSI a production contract for the QF-86E. Beginning in late 1976, several Canadair Sabre Mk. 5s were converted by FSI to QF-86E production standard, being fitted with a transponder, an interface control unit, a flight control and autopilot system, flight Termination set, a maneuver programmer, a television camera, and mission-related systems, and deliveries of QF-86Es to the US Army's White Sands Missile Range in New Mexico began in mid-1977. More than fifty production QF-86Es were delivered to the US Army, including the one Sabre Mk. 6 (ex-RCAF 23454, ex-N186F) that had been acquired in the early 1970s by Laidlaw, and they retained the RCAF serials on their vertical stabilizers despite being given a new paint scheme. A great majority of QF-86Es were destroyed by surface-to-air weapons, with the first anti-aircraft kill against a QF-86E being scored on October 12, 1978 with a Patriot SAM, and the Army ended the QF-86E drone program in June 1986.

Left: Four QF-100Ds and one QF-100F lined up in a row at Tyndall AFB in western Florida, April 25, 1990.
Right: QF-100D serial number 56-1341 on outdoor display at the Planes of Fame Museum, photographed by me on April 13, 2019.

Just two years after the US Army began operating the QF-86E, in August 1979 Sperry Flight Systems was awarded a contract to convert nine F-100s into target drones and evaluate them as replacements for the QF-102/PQM-102 drone conversion of the F-102 Delta Dagger, with eight F-100Ds (serial numbers 55-3610, 55-3669, 56-2912, 56-2978, 56-2979, 56-3048, 56-3324, and 56-3414) and a single F-100F (serial number 56-3984) designated QF-100D and QF-100F respectively. The first two F-100Ds to be converted into drones were designated YQF-100D and fitted with cockpit controls so that they could be flown by pilots for system evaluation, and the other six F-100Ds were modified to standard US Air Force target configuration and Army requirements, while the F-100F chosen for conversion became QF-100F. Takeoff of a QF-100 drone was directed by two ground-based controllers positioned at the end of the runway. Once airborne, the drone was handed off to a third controller sitting in a fixed-base ground station and a dual redundant system was used to get the drone to the mission area and to select the maneuvers, which were pre-programmed into on-board computers. If the drone survived the mission, it was flown back to the handover point, where the two controllers at the end of the runway brought it back in for a landing. The YQF-100D first flew from Tyndall AFB in northwest Florida on November 19, 1981, and after successful flight trials of the QF-100, Sperry was contracted to convert 99 additional F-100Ds and F-100Fs to QF-100 configuration, with deliveries to the USAF's Tactical Air Command being made in late 1983. In May 1984, FSI received a contract to modify 209 F-100Ds and F-100Fs as QF-100Ds and QF-100Fs, and the first QF-100s to be made by FSI were delivered in mid-1985. Sperry finished QF-100 conversions in April 1985, while FSI's conversions of its F-100Ds and F-100Fs to QF-100s until the end of the 1980s. The QF-100s themselves sported a bright red-orange paint scheme and had a few extra blade antennas for the transmission and reception of radio signals from remote-controllers on the ground. Each QF-100 drone had a lifetime of  ten flights before being destroyed, and the QF-100s were flown over the Gulf of Mexico and used as live firing targets for F-15 and F-16 training. Many were shot down with air-to-air missiles fired by the F-15 and F-16, and some either crashed on landing or lost in flight for other reasons. The last QF-100 flight was made in July 1992, and the remaining QF-100s went back to the boneyard at Davis-Monthan AFB, by which time the US Air Force was deploying the QF-106 drone conversion of the F-106 Delta Dart.

Left: A QF-86H (serial number 52-5747) in flight, 1972.
Right: QF-86H serial number 53-1351 on outdoor display at the Planes of Fame Museum, photographed by me on April 13, 2019.

The US Army was not alone in using F-86 drone conversions as live firing targets for training aircrews flying more modern aircraft. In the early 1970s the US Navy acquired about three dozen retired F-86Hs which were converted into target drones under the designation QF-86H, and it used those aircraft for target practice by Navy fighter pilots at NAS Point Mugu and NWC China Lake in southern California. Some of the QF-86Hs were shot down with anti-aircraft, and others were retired by the end of the 1970s or lost in accidents, with a few now on static display at museums. In addition, more than 130 F-86Fs formerly operated by the Japan Air Self-Defense Force (including five license-built by Mitusbishi) were modified into target drone aircraft with the designation QF-86F, and deliveries to US Navy units began in 1980, with more than 20 F-86Fs formerly used by Japan and other US allies being used as spare parts for the QF-86F fleet. During the 1980s and continuing into the early 1990s, the QF-86Fs were used for target practice by Navy fighter pilots at NAS Point Mugu and NWC China Lake, and several were destroyed by air-to-air missiles or lost in accidents. By 1993, the last QF-86Fs were retired from service, and a few have been donated to museums. The QF-86H with serial number 53-1351 that I've seen at the Planes of Fame Museum happens to include a few components from F-86H serial number 52-2074, possibly because when 53-1351 was retired and stripped of several non-vital parts, the latter Sabre had a few parts of its derelict airframe used to restore 53-1351. 

References:

Curtis, D., 2001. North American QF-86E/F/H/Sabre Full Scale Aerial Targets. Simi Valley, CA: Ginter Books.

Doug, J., 2011. "QF-100: The Final Hun." The Intake 1 (17): 20-26. (PDF link here)

Johnsen, F.A., 2024. Q-Birds: American Manned Aircraft as Drones. Manchester, UK: Hikoki Publications. 

The brave flying classroom from Downey: the Vultee Valiant

A lot of people, myself included, always regard the Texan as the most prolific trainer aircraft ever built in southern California in World War II. However, the Texan itself wasn't the only mass-produced trainer made in southern California during the war, because Vultee undertook development of a monoplane trainer, the Valiant, which became the only mass-produced trainer aircraft to be designated in the BT (Basic Trainer) designation sequence. Despite having a relatively brief military career with the US armed forces, the Valiant itself went on to become the preeminent US military basic trainer of World War II, with over 200,000 new service pilots flown on this aircraft.

An in-flight study of the sole Vultee BC-3 (serial number 39-720), the ancestor of the Vultee Valiant.

The story of the Valiant begins in 1938 when Vultee chief designer Richard Palmer proposed a multi-purpose aircraft progressively derived from the company's V-1 single-engine airliner for use a fighter and trainer. While the fighter design became the Model 48 (US military designation P-66), the trainer iteration, designated Model 51 or BC-51 by Vultee, was submitted for a requirement by the US Army Air Corps for a new Basic Combat (BC) trainer. The Model 51 had an aluminum, semi-monocoque fuselage, a four-panel wing with NACA airfoil sections and slotted flaps, wide-track, inward-retracting main landing gear, and a "greenhouse" cockpit canopy, and power was supplied by one Pratt & Whitney R-1340 Wasp radial piston engine. One Model 51 prototype was completed and it first flew on March 24, 1939, receiving the serial number 39-720 after being delivered to Wright Field on June 24, and the designation BC-3 was assigned to this aircraft. Although the Model 51 met or exceeded performance parameters laid out in the 1938 BC requirement, the Army Air Corps by then had already ordered the rival North American BC-1A design (the immediate ancestor of the AT-6 Texan) into series production, so the Model 51 remained a prototype only. 

Left: A Vultee BT-13A Valiant (serial number 42-1453) at Minter Field near Bakersfield, California, on March 1, 1943.
Right: An in-flight study of an SNV-2 (Navy equivalent of the BT-13B).

Even before the BC-3 flew, Vultee proposed a derivative of the BC-3 with one Wright R-975 Whirlwind radial engine for the export market, the Model 54 Valiant, and it also envisaged the Model 54A basic trainer subvariant of the Valiant with fixed landing gear and one Pratt & Whitney R-985 Wasp Junior radial engine. The Model 54 prototype (civil registration NX21753) first flew on June 9, 1939, but its performance was disappointing and the aircraft had to be re-engined with an R-1340 to improve speed and altitude capabilities, but not long before it crashed during a test flight on November 15. The Model 54A prototype (civil registration NX21754) made its first flight on July 28, 1939, and on September 16 the US Army Air Corps placed an order for 300 production Model 54As (serial numbers 40-810/1109), assigning the designation BT-13 to the Model 54A basic trainer. Deliveries of the BT-13 Valiant to the USAAC began in June 1940, and one skeletal airframe was built to delivered to the USAAC earlier that year. The BT-13A variant, of which 6,607 aircraft (serial numbers 41-1211/1710, 41-9587/9979, 41-10410/11586, 41-21162/23161, 42-1164/1743, 42-42201/43257 and 42-88674/89573) were built, was fitted with an R-985-AN-1 and lacked wheel fairings. The BT-13B was a BT-13A with 24-volt electrical system, and 1,125 BT-13Bs (serial numbers 42-89574/90698 and 44-31511/32160) were constructed. During the 1941-1942 timeframe, a temporary shortage of R-985 engines led to 1,693 Valiant trainers (41-9980/10409, 42-1744/2063 and 42-41258/42200) being fitted with the R-975 Whirlwind engine and designated BT-15. Of the 3,350 BT-13As ordered under a combined Army-Navy contract for additional BT-13As, 1,350 were delivered to the US Navy with BuNos 02983/03182, 05675/05874, 12492/12991 and 34135/34584 and given the designation SNV-1, with deliveries beginning in mid-1941 (two more SNV-1s were delivered to the US Coast Guard with the serials V222/223). In addition, 650 BT-13Bs were accepted by the Navy with BuNos 44038/44187 and 52050/52549, and the designation SNV-2 was assigned to these aircraft; several SNV-2s were designated SNV-2C after being modified to use an arrestor hook for carrier landings and other carrier-compatible equipment. One BT-13A (41-9777) was designated XBT-16 after being modified by the Vidal Research Corporation with a fuselage and wing empennage made from plastic, but during flight tests in 1942-1943 the XBT-16 came out 110 pounds heavier and 5 miles per hour slower than the BT-13, so it did not enter production.

Left: A BT-13B Valiant (serial number 42-90054) at the Planes of Fame Museum, photographed by me on April 13, 2019. 
Right:A BT-13B Valiant (serial number 42-89607) at the Yanks Air Museum, photographed by me on July 10, 2016.

The Valiant was not only produced in greater numbers than other trainers with BT-series designations but also trained more aircrews than the Texan or any other American aircraft in World War II, partly thanks to Vultee completing production Valiants ahead of schedule. While in service with basic training units of the US Army Air Force Training Command (USAAFTC) and US Navy, the Valiant itself was nicknamed the "Vultee Vibrator" because of its behavior when approaching its quite violent stall (75 mph/clean), so while capable of almost any aerobatic maneuver in skilled hands, its widespread use in a wartime system with a high casualty rate led to it gaining an undeserving reputation as a "Widow Maker". Despite much mishandling, there is no record of an in-flight structural failure occurring to any Valiant aircraft. By the end of World War II, as training requirements diminished, the USAAFTC retired the BT-13 and BT-15 from training units while the Navy withdrew its SNVs from service in May 1945 (the last active SNV-2 was stricken from the Navy inventory in April 1946). Large numbers of Valiant trainers were sold as surplus on the civilian market in the post-World War II environment, many being used for agricultural purposes. From 1942 onwards, Valiant trainers were sold under Lend-Lease to Argentina, Bolivia, Brazil, Chile, China, Colombia, Cuba, Dominican Republic, Ecuador, El Salvador, Guatemala, Haiti, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, and Venezuela, and after World War II forty Valiants were delivered to France, while one Valiant became the first operational aircraft of the Indonesian Air Force and smaller numbers were delivered to Israel, Egypt, and the Philippines. When the US Air Force replaced the AT, BT, and PT basic mission categories with a T-for-Trainer category in 1948, a number of surviving BT-13As were redesignated T-13A (confusingly, Stearman Kaydets still in the Air Force inventory became T-13B and T-13D).

Like the Texan, the Valiant remains popular with warbird collectors and can be seen at airshows across the US. In an interesting footnote, nine Valiants were painted to closely resemble Aichi D3A "Val" dive bombers during the production of the 1970 war film Tora! Tora! Tora! by Twentieth Century Fox (four Texan/Harvard trainers were painted to resemble the Mitsubishi A6M Zero and Nakajima B5N "Kate" for the film as well) due to the fact that no intact examples of the Japanese aircraft used in the attack on Pearl Harbor were airworthy when the movie hit theaters. One of the Valiants painted in the likeness of the "Val" during the filming of Tora! Tora! Tora! is now in airworthy condition as a warbird at the Planes of Fame Museum.