Unsuccessful experimental and prototype fighters assigned numbers in the teen range (13-19) are generally not considered part of the series.

Natalia had gone on ahead, to the original take-off site they had used with the prototype fighter.

The prototype anti-Zeppelin fighter had a crew of three to five and an intended endurance of 9-18 hours.

Although the government did not expect bids from its own aircraft industry, IAR produced several prototype fighters in response to the tender.

The two prototype fighters were the first airplanes to blend stealth with agility and high-speed, supersonic cruise capability.

Boeing is already building a prototype unmanned fighter for the Air Force, a project that many industry officials say is Boeing's to lose.

The company started to design a prototype fighter in the early 1920s based on earlier wartime designs like the Zeppelin-Lindau D.I.

Private-venture prototype fighter, one built.

The Sukhoi Su-17 (Aircraft R) was a prototype Soviet fighter.

Albatros D.IX was a German prototype single-seat fighter built in early 1918.