07/31/2018. Remarks by Johan Visschedijk: "About two dozen P-63s were modified with a second cockpit in the rear fuselage for use as instrument and equipment test beds, these were known as TP-63As and TP-63Cs. The pictured aircraft was the ex P-63E-1-BE, built under the USAAF serial 43-11728. It was registered to Bell on February 4, 1946 and used as a test bed, note the nose probe. The registration was cancelled on June 2, 1953. It was donated to the USAF Museum in 1958 and subsequently it was put on display marked and painted in the unusual color scheme of the RP-63A-11-BE 42-69654, a Pinball aircraft as described below.

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During 1943, the P-63 was involved in a new program the purpose of which was the training of the medium and heavy bombers' gunners. The idea was to use aircraft with specially reinforced surface skin as gunnery targets against which frangible bullets (made of lead and plastic) could be fired. In August 1944, under contract No. AC29318, Bell converted five P-63As. All armament and internal armor was removed. All skinning was replaced by thicker metal sheet, the upper fuselage air scoop was replaced by a clam-shell intake and the canopy was armored with a 1.5 in (38.1 mm) windshield and 1.0 in (25.4 mm) side windows. No less than 110 microphones were buried under the skin. Each hit was recorded on an automatic counter located on the instrument panel and a light hidden in the propeller hub flashed.

These aircraft, designated RP-63A-11-BE, were powered by the 1,325 hp Allison V-1710-93 engine with water injection and had their internal fuel capacity increased to 126 gal (477 l). The first of them flew for the first time on September 1, 1944, with Robert M. Stanley at the controls. The first flight tests were not completely successful because the modifications had altered the position of the center of gravity by a considerable extent. This fault was overcome by repositioning some equipment inside the airframe. The hub light was hardly visible and additional lights were installed around the rear fuselage, hence the type became known as Pinballs.

A first batch of 95 aircraft was ordered in due course. These were designated RP-63A-12-BE. A second production batch concerned 200 RP-63C-2-BEs which were powered by the 1,325 hp V-1710-117 and had 1,487.7 lb (674.8 kg) of armor. A third and last batch totalled 32 RP-63G-1-BEs with the 1,425 hp V-1710-135 and 2,164.9 lb (982 kg) of armor. Additional contracts for 420 more RP-63Gs were cancelled. In 1948, these target-aircraft had their designation changed to QF-63A, QF-63C and QF-63G respectively. They were used by the Yuma Flexible Gunnery School and by the 79th Fighter Training Wing."