K5DH wrote:
Regarding the B-24 used as a jet engine test bed, I recall seeing pictures of an A-26 Invader that was similarly modified. Or, at least I think I recall...
I think you did Dean, I'd say it was this one perhaps?
Douglas XA-26F 44-34586 Oakland Airport, May 1949
Per NMUSAF fact sheets: The XA-26F was the third aircraft in a series of improved A-26s. All three aircraft were designed for a more powerful version of the Pratt & Whitney R-2800 radial engine. The XA-26D was an updated B-26B (solid gun-nose type), the XA-26E was an updated B-26C (clear bombardier's nose) and the XA-26F was essentially an XA-26D design with a General Electric J31 turbojet engine mounted in the rear fuselage.
The jet engine was mounted just behind the wing. The air intake for the jet was mounted on top of the fuselage in place of the dorsal gun barbette. The ventral gun barbette was also removed to make room for the engine itself. The jet exhaust pipe ran through the aft fuselage and out the tail between the horizontal stabilizers. The fuel tank for the jet was installed in the bomb bay and restricted the aircraft to strafing missions only.
Since the project was initially intended to test the jet engine, all forward armament was removed. As testing continued, the forward guns were reinstalled. Eight .50-cal. machine guns were mounted in the nose and the wings had six more internal .50-cal. machine guns. The standard three-blade propellers were replaced with four blade versions and large prop spinners were added to improve streamlining.
The XA-26F had a top speed of about 435 mph with all three engines operating at full power. The XA-26D (basically the same airplane without the jet) had a top speed of 405 mph. The performance increase of the XA-26F over the XA-26D was judged insufficient to warrant production and the program was canceled after completion of testing.