01/22/2007. Remarks by Dave Simpson: "This first prototype, serialed 41-786, was built with abreviated tail surfaces, as shown in this photo and above, and was not painted initially but left in bare metal with minimal USAAF markings applied, so it was really nice to see that at some point the aircraft was "dolled up" in regular USAAF style livery, quite possibly after rework from the initial taxiing difficulties. This aircraft first underwent trials on April 1943 at which time it was found to experience dangerous yawing during high speed taxiing so it had the undercarriage reworked including new manual hydraulic brakes.
The first flight was delayed by engine testing difficulties and not accomplished until September 30, 1943, by test pilot John Myers from Muroc Dry Lake (now Edwards AFB), California, USA. From accounts it appears to have made very few short duration flights and it was wrecked before the end of the year when during a high-speed taxiing run the port mainwheel tire blew out and the aircraft somersaulted. It is unfortunate that the original Pratt and Whitney X-1800 liquid cooled engine was never availble from the manufacturer as their replacement motor an aircooled R-2800 seems to have possibly been a marginal replacement...
The second prototype, serialed 42-38353, had considerable alterations, the center of gravity was moved forward, the upper vertical surfaces were enlarged, and novel wing tip bellows were added to operate split flaps in the drooped wingtips for added directional control but basically the same Pratt & Whitney R-2800-29 radial engine was retained. This aircraft was delivered already painted in standard USAAF livery as shown in the pictures. First flight was made by test pilot Harry Crosby, also from Muroc Dry Lake, on March 23, 1944.
The pilots were complaining of heavy controls, excessive fuel consumption, tail heaviness on the ground and that the nose wheel would not lift off the ground at speeds less than 160 mph (257 kmh). Flight testing had also revealed that the aircraft was not able to attain the estimated manufacturers performance numbers, so by May 30, 1944 it was decided that the NACA should use their large wind tunnel at Moffett Field to acertain what was limiting this airframe... So it appears that after the tenth flight the aircraft was parked to await testing that never happened due to NACA having other more pressing commitments... One can only wonder what they would have discovered."