The Fisher P-75 Eagle had its origins in a 1942 proposal to meet an Army requirement for a fighter with an extremely high rate of climb. The proposed aircraft was to be powered by the 24 cylinder Allison V-3420, the most powerful liquid-cooled engine then available, and constructed from the components of existing aircraft, namely the outer wing panels of the P-51 Mustang; the tail assembly of the Douglas A-24; and the landing gear of the F4U Corsair. The P-51 wing panels were replaced by those of the P-40 Warhawk in the early stages of the design. Like the P-39 Airacobra, the engine was located mid-fuselage, driving two coaxial contra-rotating propellers connected by dual drive shafts running under the cockpit.
The Fisher Body Division of GM received a contract for two XP-75 prototypes in October 1942; the first aircraft made its initial flight on November 17, 1943. Unsurprisingly, flight tests of the misshapen aircraft indicated mediocre performance. This, along with a mission change from interceptor to long-range escort, resulted in major changes to the original design, with the concept of using major components from existing aircraft being largely abandoned. The Army Air Force ordered six XP-75s of the revised configuration along with 2,500 P-75As, with the stipulation that the entire order could be cancelled if the first P-75A proved to be unsatisfactory.
The improved XP-75 was still unsatisfactory, with three crashing during flight testing. The contract was cancelled on November 8, 1944, with only eight XP-75s and six P-75As being built. While flight testing had worked out the worst of the aircraft’s vices, the Eagle was no longer required in its original role, could not be quickly deployed, and possessed no significant advantages over aircraft already in production.
The brochure displayed above was issued on May 20, 1944 when there was still the possibility that the Fisher P-75 could see large scale production and enter combat. Many of the photos are heavily retouched and portray an interesting intermediate stage between the original XP-75 and the final P-75A, retaining the Douglas-style tail of the former but having the bubble canopy of the latter; there are likely numerous detail differences between the designs as well. The brochure provides many excellent detail drawings and photos, making it an ideal reference for modelers or those wishing to develop a better technical understanding of this flawed but not entirely unappealing aircraft, one of a handful of types powered by the mighty Allison V-3420. More photos and information on the Fisher P-75 series can be found on Wikipedia, the National Museum of the US Air Force site, and on Flickr.
All images from NARA Archives II, College Park, MD, RG 18
“P-75 Series Airplanes Advance Descriptive Data,” May 20, 1944, in the files of the National Archives II at College Park, MD, RG 18