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From Aeroplane Monthly, May, 1990
Continuing the theme of unorthodox military transport Every once in a while this office receives photographs of unfamiliar aircraft that send us diving into the reference books for positive identification. Last year Derek Sparkes of Stroud sent us a batch of photographs depicting a small two-seat twin-boom glider, a selection of which appears on these pages. There was no clue to the identity of the glider just the name of the photographer, L. P. Clarke of Santa Monica Boulevard in Hollywood, USA.
Several hours of leafing through our own archives revealed nothing. Letters were written to contacts in America two of which provided positive identification. Chalmers "Slick" Goodlin, former Bell X- I test pilot and now chairman and president of the Burnelli Company Inc in Miami, provided the first lead. Noting that the glider had a Burnelli-type lifting fuselage, my first line was to contact Goodlin to see if there was any direct connection with Burnelli. Goodlin recalled Burnelli telling him that, early during the last war, Gen Arnold, US Army Air Corps Commanding General, telephoned him (Burnelli) and asked him to travel to Washington. On his arrival at the Pentagon Gen. Arnold advised Burnelli that a glider project had been offered to the Army Air Corps by the General Airborne Transport Company. The Air Corps was impressed with the performance figures produced by GAT but Arnold recognised that the glider was clearly based on the Burnelli concept and felt obliged to bring the fact to the attention of the designer. He asked Burnelli to grant a licence to GAT so that the project could proceed. An agreement was entered into and Burnelli received a down-payment.
The Bowlus glider with two up about to be towed into the air at Muroc. The glider concerned was the XGG-16A, designed by William Hawley Bowlus, a talented designer who had cut his teeth in the early Twenties with Mahoney-Ryan and the company's series of Brougham high wing monoplanes. He became even more noted for his glider designs under the banner of his company Bowlus Sailplanes. Early in 1942 Bowlus was awarded a contract by the USAAF for two troop gliders -- the eight-place XCG-7 and the 15-place XCG-8. The smaller glider was structurally unsound and failed official tests. The larger XCG-8 was really too large for Bowlus to handle and Douglas Aircraft came to the rescue. But this glider, too, failed to come up to scratch structu rally; and both projects came to naught.
Scale model Construction of the test model was carried out in his tiny shop, a former dry cleaning shop where there was just sufficient room to build the two-seat open-cockpit prototype. On completion, the glider was flown at Muroc Dry Lake, now the sight of Edwards AFB. The glider flew well and Bowlus and partner Albert Criz set about designing, building and marketing the full-size glider, the XCG-16. The XCG-16A was an all-wood twin boom military transport glider of 91ft 10in span, featuring an aerofoil-sectioned lifting fuselage between the booms in which either cargo or troops could be carried in two 16ft x 7ft compartments. The load could be four tons of cargo or 48 armed troops. The front of the wing opened upwards and downwards like a pair of jaws, the bottom doors doubling as a loading ramp. A mock-up of the troop accommodation shows that the compartment tapered towards the trailing edge, allowing little headroom for those unfortunates at the back. The crew of two sat in tandem beneath a continuous canopy atop the centre section. A single fin and rudder was mounted on the tailplane between the booms. The tricycle landing gear was retractable, and flaps were fitted to the outer wing panels and the fuselage centre section. The XCG-16 was constructed mainly of plywood, although all flying surfaces and flaps were fabric-covered. The XCG-16 was completed and ready for test-flying in the summer of 1943. It was offered to Wright Field for evaluation, but the company elected to carry out tests itself. These appear to have gone well and Bowlus authorised a demonstration for top brass on September 11, 1943 from March Field. The pilot of the glider was Col P. E. Gable, deputy director of the Army Air Corps assault glider programme. The copilot was Howard Morrison, a long time associate of Bowlus and a test pilot. Several VIPs set off on the flight. They included Richard Dupont, special assistant to Gen Arnold; Col Ernest Gabel, another glider specialist on the staff of the Chief of Staff of the Air Force, and C. C. Chandler, thrice soaring champion. In order to bring the glider up to more-or-less full load, bags of sand and lead shot were loaded aboard but apparently were in securely lashed some reports say they were not lashed to the glider at all. The glider was towed off from March Field by a Lockheed C-60. During turbulence the bags shifted aft and set up a porpoising moment, forcing the C-60 to cut loose. Thc glider entered a flat spin from which it failed to recover. Only Bowlus and one other managed to take to their parachutes the other occupants, including Dupont, perished. One report says that Gable had less than 6 hours total time on gliders and allowed the XCG-16 to fly into the wake of the C-60, causing the glidcr to pitch violently and breaking the cable. The ballast shifted aft, and the glider entered the flat spin.
The newly completed glider in the confined
The same glider airborne at Muroc.
The glider pictured immediately after a landing.
Possibly the same glider with modified rudders and an American military colour scheme.
The Bowlus scale glider well and truly
Crude mock-up showing troop positions
Costly, late . . . In his pilot's test report summary, Tuntland had this to say about the handling of the XCG-16: "In my opinion the XCG-16 has excellent handling qualities. During the flight tests I had the impression of flying a large sail plane. It is laterally stable in that it has a tendency to over-bank in steep spirals. I always had good lateral control at the slower airspeeds and higher angles of attack. Longitudinal control was normal with high elevator forces noted at increased airspeeds. "Directional control was good throughout the normal speed range. There was sufficient vertical area in the tail group to maintain good directional control throughout the approach and landing roll, even in moderate crosswinds. There was no tendency to yaw before or during the landing roll except in a crosswind, where normal correction was satisfactory. The subject aircraft is very manoeuvrable, being capable of rolling from one vertical turn to another in a minimum of time. On one occasion I was able to soar the aircraft in moderate lift conditions. Stalling characteristics are excellcnt. The first stall warning is indicated about 15 m.p.h. above actual stalling speed. This aircraft made normal landings at between 40 and 75 m.p.h. with the average about 48 m.p.h. A minimum of longitudinal trimming control was necessary in a c.g. shift from 24 per cent MAC to 36 per cent MAC. Normal landings were made with the flaps retracted at approximately 70 m.p.h. "The copilot's lateral vision is rather poor from the rear cockpit. The pilot's front cockpit vision is excellent forward, and good towards the sides. "Thc ground cushioning effect is very noticeable and is a desirable feature of the type, assisting soft ground contact from a rough approach. "Any glider of either tricycle or conventional landing gear that has sufficient vertical tail surfaces for directional stability will tend to turn into the wind during crosswind landings at high or low angles of attack. In this respect the XCG-16 glider has absolutely no objectionable qualities compared to any other aircraft with which I have had experience. The tendency to turn could be readily corrected by the action of the rudder and of the brakes at slow speeds." The report is dated October 31, 1944. Despite the favourable flying qualities of the XCG-16 there were a number of operational snags; rather too many, as it turned out. These included: inadequate protection in the event of a crash; insufficient exits for crew in the event of an emergency; unsatisfactory loading ramps; poor location of flight equipment, and critical lateral loading. After tests by the AAF Board at Clinton Army Air Field and at Orlando, the contract for the XCG-16 was cancelled on November 30, 1944.
Grant MacLaren |