#prototype aircraft

[stone-cold-groove]

A USAF Convair XB-36 undergoing flight testing.

[nocternalrandomness]

A Convair XP5Y-1 seen on San Diego Bay the day of it's first flight - 18 April 1950

(U.S. Navy Photo)

[doctor-uchron99]

Il-20 (1948) - Soviet attacker-bomber prototype. Got its first flight on 5th of December, 1948. Never continued because of jet aviation, high vibrations and stall risk when firing.

[pattern-53-enfield]

The first flying prototype of the Fisher XP-75 Eagle high-altitude strike fighter. Using the best liquid-cooled engine available, the Eagle was only barely more manueverable than the P-38 Lightning or the P-51 Mustang, and the project was cancelled in 1944.

[stone-cold-groove]

The North American Aviation XB-70A Valkyrie.

[stone-cold-groove]

The business end of a Douglas XTB2D Skypirate.

[nocternalrandomness]

The only surviving example of a Vought XC-142A preserved at the National Museum of the US Air Force

[nocternalrandomness]

French Potez 41M prototype heavy bomber photographed in 1934