In the ferocious rush of World War II, the U.S. was scrambling to build fighters capable of outboxing the enemy machines, and the Fisher P-75 Eagle was to be the next great interceptor — fast, powerful, and able to soar quickly into the fray. Instead, it became a warning: an expensive and ambitious failure that spectacularly flopped and left lessons in its wake rather than wins.
The story begins in 1942, when the Army Air Forces needed a fighter with exceptional climb performance. General Motors’ Fisher Body Division welcomed the opportunity to enter aviation. Already prominent in producing auto bodies and Sherman tanks, Fisher wanted to design an exceptional aircraft of their own. They hired Don Berlin, an experienced designer with the Curtiss P-36 and P-40 under his belt, to lead the effort.
Fisher’s method was ambitious, perhaps even dangerous. They wanted to construct the P-75 out of a combination of other aircraft parts: P-40 Warhawk wings (later traded in for Mustang wings), a Douglas SBD Dauntless tail, and F4U Corsair landing gear.
The engine was placed behind the cockpit, driving contra-rotating propellers via long extension shafts — not a typical configuration but one inspired by the Bell P-39. The idea was to accelerate the process by implementing established components and make the plane combat-ready in only six months.
But airplanes are not cars, and what is good on an assembly line does not necessarily fly. The Allison V-3420 engine — essentially two V-1710 engines bolted together — was a good idea on paper, but it overheated and failed. The patchwork structure of the airframe resulted in a rough flight experience: iffy handling, wobbly spins, and sluggish roll rates. Its center of gravity was off, and by and large, it just did not work as desired.
When the war changed direction, so did the role of the P-75. It was reconfigured as a long-range escort, and that entailed incorporating additional fuel, a new tail, a bubble canopy, and a more potent engine. But these changes just made it heavier, more complicated, and even more costly.
The military quickly found it was faster and more economical to modify tried-and-true, battle-proven aircraft such as the P-38 Lightning and P-51 Mustang than to struggle with the P-75’s accumulation of woes.
Flight testing was bumpy. The first test plane flew in November 1943 but displayed instability and disappointing power. A number of crashes during testing resulted, some with disastrous consequences. It never made it to the promised top speed, and its rate of climb was not so hot.
As of October 1944, the Army gave up — barely a few dozen prototypes and early examples ever made it past the factory floor, and most were discarded. Today, only one restored P-75 remains at the National Museum of the United States Air Force in Dayton, Ohio.
The Fisher P-75 Eagle is today a cautionary tale for designers and war planners. It demonstrated that just using parts from various planes does not substitute for careful, holistic design. And that the velocity of car production’s logic does not always apply to the intricacies of flight. As another aviation commentator described it, the P-75 was the “champion” of “spare parts fighters” — a testament to what occurs when urgency and ambition meet without sufficient experience at 20,000 feet.
In the end, the P-75 teaches us that real innovation takes unity, and on occasion, adhering to tried methods is the best approach to winning a war.