Convair Model 48 Charger The Convair Model 48 Charger was a prototype light attack and observation aircraft of the 1960s , developed to meet a requirement for a dedicated counter - insurgency ( COIN ) aircraft . It was a two - seat , twin - boom aircraft powered by two turboprop engines which lost out to the North American Rockwell OV - 10 Bronco of similar layout , only a single example being built . Design and development . In 1959 , two United States Marine Corps officers developed the concept of a small low cost aircraft capable of providing close air support to the U . S . Marines , capable of operating from roads close to the battlefield , the concept being known as the Light Light Marine Attack Aircraft ( L2VMA ) . As interest in such an aircraft grew , with interest from the US Army for a similar type , the Convair Division of General Dynamics started studies into counter - insurgency aircraft in 1961 . In 1963 , the various requirements were merged into a tri - service specification for a Light Armed Reconnaissance Aircraft ( LARA ) , to be used not just by the U . S . Marines and Army , but also by the United States Air Force for COIN and forward air control roles , and to be available for export . The specification produced responses from nine manufacturers , including Convair , who submitted its Model 48 Charger in March 1964 . The Model 48 was a twin - boom monoplane , constructed mainly from aluminium , with fiberglass nose , rear fuselage and wingtips , with a retractable nosewheel undercarriage . It was powered by two Pratt & Whitney Canada PT - 6 ( military designation T - 74 ) , driving three bladed propellers . Its wings were of relatively short ( 27 ft 6 in / 8 . 38 m ) span , which meant that most of the wing was in the slipstream of the propellers , increasing the effectiveness of the full - span trailing - edge slotted flaps and leading edge slats inboard of the engines , which together acted to deflect the slipstream , giving a form of vectored thrust , in order to reduce takeoff and landing distances . The outer trailing - edge flaps doubled as ailerons , which were supplemented by spoilers at low speed . The aircraft was fitted with a large , all - moving tailplane which attached to the vertical fins located at the ends of the tailboom ( s ) , with the tailplane having somewhat greater span ( 20 ft ( 6 . 1 m ) ) than the distance between the tailbooms . Pilot and observer sat in tandem under a sliding canopy , while the rear fuselage held a cargo bay with a hinged tail cone capable of carrying 2 , 000 lb ( 910 kg ) of cargo , which could include a complete PT - 6 engine , or five paratroopers , in extremely cramped conditions , with a sixth paratrooper in the observer ' s seat . Four 7 . 62 mm machine gun s were mounted in pods on the side of the fuselage , while 2 , 000 lb ( 910 kg ) of external stores , including bombs , rockets and gun pods , could be carried on hardpoint s under the wings and fuselage . To meet the specification ' s requirements for amphibious operations , it could be fitted with two large floats . Operational history . Convair started construction of a prototype as a private venture before a winner of the LARA competition was announced . In August 1964 , the US Navy announced North American Aviation ' s design , the NA - 300 ( later to become the OV - 10 Bronco ) as the winner of the LARA competition . The U . S . Marine Corps and U . S . Air Force favored the Charger , however , and protested against the U . S . Navy ' s decision , and Convair continued construction of their prototype , which made its maiden flight on 25 November 1964 . After initial flight tests , the Charger was modified with an increased wingspan and modified tail to improve low - speed control . The Charger demonstrated excellent STOL capability , taking off over a 50 ft ( 15 m ) obstacle in 485 ft ( 148 m ) with a normal payload . This was better both than the LARA specifications requirement of 800 ft ( 244 m ) , and the Bronco . The Charger was awarded a 100 - hour joint service flight test contract where the prototype would be flown by representatives of the U . S . Navy , Marine Corps , Army and Air Force . If orders followed , it was planned to build the production aircraft with a deeper and longer fuselage allowing full dual controls to be fitted . The prototype crashed on its 196th test flight on 19 October 1965 , owing to pilot error by its U . S . Navy test pilot , however , and further development was abandoned .