In response to a USAAC requirement for a new fighter aircraft, Republic Aviation engineer Alexander Kartveli proposed the AP-10 lightweight high-altitude interceptor on August 1, 1939.[1] As originally proposed, the AP-10 was to have been powered by a 1,150 hp Allison V-1710-39 12-cylinder inline engine and have an armament consisting of two nose-mounted .50 in (12.7 mm) M2 Browning machine guns.Kartveli revised the AP-10 by slightly increasing its size and mounting two .30 in (7.62 mm) M1919 Browning machine guns in each wing, raising the gross weight to 6,570 lb.[2] Expecting the USAAC to reject the XP-47 for the more suitable Curtiss XP-46, Republic canceled the XP-47 and XP-47A and Kartveli began an extensive redesign of the aircraft.[2] Armament was increased to eight M2 Brownings, four mounted in each wing, making it one of the heaviest-armed fighters considered by the USAAC at the time.It was powered by a 1,960 hp XR-2800-21 engine and featured an elliptical wing, an all-metal construction (except for the fabric-covered control surfaces), and a hinged canopy.The resulting P-47C featured a redesigned metal rudder, as the original fabric-covered unit was prone to tail flutter which frequently led to crashes.The initial production block was based on the P-47C-2-RE[4] or C-5-RE,[8] but with two additional cowl flaps (for a total of five) on each side (this was absent on early aircraft, making them indistinguishable from P-47Cs).In an attempt to improve the performance of the Thunderbolt, Republic began a project to install a 2,300 hp Chrysler XIV-2220-1 16-cylinder inverted-V engine in two P-47D-15-RE airframes in August 1943.A production version of the XP-47J was canceled in favor of another Thunderbolt development, the XP-72, as were plans for installing an R-2800-61 engine with contra-rotating propellers.[18] Deliveries began in December 1944, though engine problems delayed their combat debut until a few weeks before the end of the war in Europe.[20] The aircraft was a development of the bubbletop P-47D, but was to be powered by 3,450 hp Pratt & Whitney R-4360-13 Wasp Major 28-cylinder radial engine driving contra-rotating six-bladed Aeroproducts propellers and armed with six M2 Brownings.
Eleventh production P-47B-RE, s/n 41-5905, with both the sliding canopy and original rear-cockpit windows.
The sole XP-47E, s/n 41-6065
P-47C-2-RE, s/n 41-6182
'Astra', a two-seat conversion of a P-47D assigned to the
365th Fighter Group
. Apparent are the underwing pylons introduced on the P-47D-15.
An early P-47D-RA, s/n 42-22281 'Aloe Al', with three cowl flaps per side. This was later changed to five.
Airworthy P-47G-10-CU, s/n 42-25068 'Snafu', at the 2012
Duxford Air Show
.
The first XP-47H, s/n 42-23297
XP-47J, s/n 43-46952
XP-47K, s/n 42-8702, the first bubbletop Thunderbolt