Fletcher Aviation's bomb gliders

It has been long-known that US guided missile technology in World War II was very primitive at best, with American aerospace and weapons companies equipping straight-wing aircraft designs with explosives and bombs with guidance systems so those machines could function like a missile in terms of wreaking destruction on enemy targets in Europe and the Pacific. However, lost in aviation historians' discussions of early US guided missiles is the fact that in World War II the US Army Air Force and US Navy devised schemes to create bomb-laden gliders, with the Navy concocting the GLOMB (GLide bOMB) concept under the LB (glide bomb)-series designations, and the USAAF introducing the BG (Bomb Glider) category for their bomb-laden gliders. In particular, even though Radioplane and Interstate Aircraft led the way among southern California aviation companies in building radio-controlled bomb-packed aircraft, one aircraft manufacturer in the region involved in making explosive-filled aircraft in World War II that is overlooked by most aviation historians is Fletcher Aviation. Thanks to a copy of Bill Norton's 2012 book American Military Gliders of World War II, I now have had the liberty of illuminating and clarifying in detail the oft-forgotten story of Fletcher Aviation's efforts to develop explosive-filled glider designs, the BG-1 and BG-2.

The Fletcher Aviation Corporation was founded in Pasadena, California, by the Fletcher brothers (Wendell, Maurice, and Frank) in 1941, initially aiming to build a wooden basic trainer aircraft for the US Army Air Force. The resulting trainer design conceived by Wendell Fletcher, the FBT-2, had a Wright R-760 Whirlwind radial piston engine and a fixed tailwheel undercarriage, with seating for a pilot and flight instructor. The FBT-2 prototype (civil registration NX28368) flew in 1941, but the design failed to attract serious interest from the US military. Fletcher eventually decided to convert the FBT-2 prototype into a drone control aircraft under the designation CQ-1 (CQ=drone control aircraft), with tangible design changes including the replacement of the conventional landing gear by a tricycle undercarriage, the elimination of the turtle deck, and the swapping of the R-760 for a Pratt & Whitney R-985 Wasp Junior. The prototype CQ-1 (serial number 41-38984), would later form the basis of the PQ-11 target drone, of which ten were ordered (serial numbers 42-46892/46901). However, the PQ-11 was cancelled by the USAAF in favor of the Culver PQ-8 Cadet, and the ten PQ-11s on order were completed as a new bomb glider design based on the CQ-1, the BG-1 (designated Model 17 by Fletcher) (Andrade 1979).

Left: Fletcher BG-1 during testing at Muroc Army Air Field (now Edwards Air Force Base), spring 1942 (courtesy of National Museum of the US Air Force); Right: 3-view drawing of the Fletcher BG-1 bomb glider (courtesy of Bill Norton, via George Cully)

 The BG-1 was basically a CQ-1/PQ-11 with the R-985 engine removed and replaced by remote control systems and a round encasing for a 2,000 pound AN-M34 warhead. For combat missions, the BG-1 would be released 11 miles from an enemy target by a bomber and the operator aboard the towplane would guide the BG-1 to its target via TV screen (Norton 2008, p. 129). While the BG-1 had a simple windscreen and overturn bar, the first BG-1 to be completed had the sliding canopy seen in the CQ-1 and PQ-11, and was devoid of remote control gear. On April 26-27, 1942, the BG-1 made its first tow-and-free flights at Muroc Army Air Field, with Fletcher test pilot LaVerne Browne (aka John Trent) at the controls and a Douglas B-23 Dragon bomber serving as the towing aircraft. By June, five BG-1s had been delivered to the USAAF, all equipped with a 3-axis compact hydraulic servo unit, radio equipment, electric motor throttle control, an SCR-549 television transmitter, a wind-driven generator under the rear fuselage, and bomb arming equipment. The sole CQ-1 was fitted with a mockup of a TV guidance system fairing under the left wing, with stall tests conducted on August 23, 1942 (Norton 2012, pp. 209-210). It was also planned to conduct a flight test of the BG-1 with a 1,000 lb warhead at El Paso, Texas, to avoid overload.

A 3-view drawing of the proposed Fletcher BG-2 twin-fuselage bomb glider. The similarity of the vertical stabilizer shape and tricycle undercarriage to that of the CQ-1 and BG-1 is evident (courtesy of Bill Norton, via George Cully).

Even before flight tests of the BG-1 began, in January 1942, Fletcher proposed a twin-fuselage bomb glider, the Model 16, which had the same length as the CQ-1/PQ-11 and BG-1, but had a 45 foot wingspan and a TV fairing under the inboard wing either on the centerline or in the starboard fuselage nose.* The BG-1 fuselages were joined by a center wing section and a horizontal tail, and each fuselage carried a 2,000 lb warhead. Empty weight was to be 2,432 pounds, with the gross weight estimated at 6,531 pounds and the planned stalling speed was 84 mph. The Model 16 was designated XBG-2 by the Army Air Force and on April 1, 1942, a contract was awarded to build three BG-2 prototypes (serial numbers 42-46902/46904). However, according to an Engineering Division memorandum dated June 9, 1943, flight characteristics of the BG-1 during testing were judged unsatisfactory, and so a recommendation was made for the USAAF to cancel the BG-1 and BG-2 programs. Therefore, the BG-2 program was axed on September 8, 1942 before any of the XBG-2s on order could be completed (Norton 2012, p. 210). (One more USAAF glider design was given a BG-series designation, the similarly unbuilt forward-swept wing Cornelius XBG-3, but that's another story.) For one thing, the US Army Air Force must have realized that the bomb glider concept was going to be unfeasible in practice due to the fact that the weight and drag of the bomb glider would have caused the engines of a bomber towing the glider to overheat while on a combat mission over hostile territory, but also because free-fall guided bombs were faring poorly in combat.  

*Andrade (1979, pp. 59, 96) states that the three BG-2s on contract were originally ordered as a production batch of the 8-seat Frankfort CG-1 transport glider, while the June 1946 edition of Model Designations of Army Aircraft confusingly describes the BG-2 as a transport glider (although that description actually applies to the Frankfort CG-2 transport glider project, which was to carry 15 troops). However, this assertion is refuted by the available drawing of the BG-2 from Fletcher Aviation project documents and the description of the BG-2 given in the January 1945 edition of Model Designations of Army Aircraft, and Norton (2008, p. 130) states that the BG-2 itself was derived from the CQ-1, like the BG-1. Therefore, Andrade's claim that the BG-2 was based on the CG-1 is clearly due to the mention of "CG-1" under the BG-2 entry on page 96 being a typographical error for CQ-1, because the BG-2 had the same vertical stabilizer design as that of the CQ-1 and BG-1 (see drawings and photos in Norton 2012), and was of a completely different design than the CG-1 and CG-2 (see drawings of the CG-1 and CG-2 in Norton 2012, pp. 52-53). Additionally, the XBG-2 contract was signed shortly after the CG-1 and CG-2 were cancelled without a prototype reaching the flight stage. The misidentification of the BG-2 as a CG-1 derivative isn't the only error made in Andrade's book; other mistakes in the volume include description of the Kaiser-Fleetwings XA-39 as a twin-engine aircraft (the XA-39 was definitely a single-engine aircraft like the Navy's BTK), identifying the C-127 designation with the Boeing 493-3-2 turboprop derivative of the Boeing C-97 Stratofreighter (C-127 was actually the original designation for the turboprop-powered C-124B version of the Douglas C-124 Globemaster II), identification of the Martin XNBL-2 long-range bomber project as a monoplane (the XNBL-2 was actually a biplane), and the inclusion of the Wasp Major-powered Douglas Model 423 among design studies for the Douglas XB-31 (only the 140-foot span Model 332 was designated the XB-31, and the Model 423 was envisaged in late 1941, long after the B-29 Superfortress and B-32 Dominator were selected over the XB-30 and XB-31). 

References:

Andrade, J. M., 1979. US Military and Aircraft Designations and Serials since 1909. Leicester, UK: Midland Counties Publications.

Norton, W. J., 2008. Sideshow Curiosities: American Military Glider Experiments of World War II. American Aviation Historical Society 53 (2): 113-134.

Norton, W. J., 2012. American Military Gliders of World War II: Development, Training, Experimentation, and Tactics of All Aircraft Types. Atglen, PA: Schiffer Publishing.