Subsonic second-generation Firebee targets: the BQM-34A, MQM-34D, and BQM-34S

The Firebee drone series was the most prolific unmanned air vehicle family of the Cold War to be built in the United States, with its development spanning two generations and encompassing both subsonic and supersonic variants for a wide variety of combat and non-combat roles. However, the Firebees I have seen at aviation museums in southern California so far are quite different from the first Firebees to be built for the US military in their overall appearance, especially in having a scoop intake below the fuselage. Due to the staggering diversity of scoop-intake Firebee variants designed for subsonic and supersonic flight, I am confining the scope of this post to discussing second-generation Firebee target drone variants capable of subsonic flight.

Left: A BQM-34A drone on display at the Yanks Air Museum, photographed by me on May 19, 2018.
Right: A US Air Force BQM-34A in flight. 

In the late 1950s the Ryan Aeronautical Company envisaged the Model 124 design for an improved Q-2 Firebee drone with significantly enhanced flight performance. The airframe of the Model 124 was bigger and heavier than that of the first-generation Firebee, featuring a scoop intake below the nose, increased wingspan, a top speed of 690 mph (1,110 km'h), a 1,700 lb (7.6 kN) thrust. The Model 124 was formally designated Q-2C by the US Air Force (XQ-2, Q-2A, and XQ-2B were allocated to first-generation USAF Firebee variants), and the first XQ-2C prototype flew in December 1958 with production commencing in 1960. The US Air Force soon phased out the Q-2As as it took deliveries of the Q-2C variant, and the Q-2C was redesignated BQM-34A under a new Tri-Service guided missile designation system established by the Defense Department in June 1963. Meanwhile, the US Army replaced its first-generation Firebee (Army designation XM21) with a ground-launched variant of the BQM-34A, the MQM-34D (Model 124E), which had a slightly longer wingspan and a heavier RATO booster with greater duration as well as an endurance of 107 minutes. For its part, the Navy replaced its KDA-1 and -4 drones (redesignated AQM-34B and AQM-34C respectively) with the BQM-34A in 1964. The second generation subsonic target drone variants of the Firebee would be collectively called Firebee I to distinguish them from the supersonic Firebee II (BQM-34E/F/T), and production of the BQM-34A lasted until 1982.

Left: An MQM-34D Mod II showing the nose intake distinguishing it from the baseline MQM-34F.
Right: A BQM-34S after release from a DC-130 drone control aircraft.

In the early 1970s, the US Army wanted a high-performance target drone for realistic evaluation of the FIM-92 Stinger shoulder-launched surface-to-air missile. Teledyne Ryan thus envisaged an MQM-34D variant with an air intake in the nose for one General Electric J85 turbojet, designated Model 251 by the company. Initial flight tests of the Model 251 with the J85-GE-4 variant were only partially successful, but the Model 251 was able to attain the performance characteristics of the MQM-34D after being fitted with a J85-GE-7, and an unknown number of MQM-34Ds were upgraded to Model 251 standard, which was called MQM-34D Mod II and equipped with an M232 automated flight control system. The Navy upgraded its BQM-34As with the new AN/USW-3(V) ITCS (Integrated Tracking and Control System) flight control system in the mid-1970s, assigning the designation BQM-34S to these drones, which were re-engined with a 1,920 lb (8.5 kN) thrust J69-T-41A turbojet in the early 1980s. The Firebee I production facility in San Diego was reopened in 1986 for production of new-build BQM-34S drones, many of which were fitted with an upgraded A/A37G-8A flight control system. The US Air Force in the early 1980s upgraded its BQM-34As with a Vega DTCS (Drone Tracking and Control System) and an A/A37G-14 3-axis digital flight control system while having those drones re-engined with one J85-GE-7 turbojet. All BQM-34A/S drones in Air Force and Navy service were eventually upgraded with the 2,800 lb (12.45 kN) thrust J85-GE-100 by the early 1990s, and some of these drones were fitted with a GPS receiver for more precise navigator. 

More than 5,500 Firebee I target drones of all variants were built before the end of production in the late 1980s. The US Air Force continued operating the BGM-34A into the early 2000s, and five BQM-34As were used to lay corridors of chaff during the US invasion of Iraq in March 2003 after being modified by Northrop Grumman in February of that year to BQM-34-53 configuration; two were ground-launched and three were launched from a DC-130, and these drones were painted charcoal black to avoid enemy detection. The US Air Force eventually retired its remaining BQM-34As from service as the newer BQM-167 Skeeter began entering operational service, but the Navy still has a handful of BQM-34s in service, having upgraded them with new autopilot and navigation systems in the mid-2010s, although these are being phased out due to deployment of the newer Composite Engineering BQM-177.