Another Vought aircraft, the Mach 2 cruise missile SSM-N-9 Regulus II would also use a Ferri scoop inlet and ventral fin.

The inlet used three shock waves with external and internal supersonic compression as the air slowed before entering the engine.

[7] The size of the two fins needed on the Crusader III, with a speed reaching Mach 2.7, required them to be turned horizontally when taking off and landing.

To ensure sufficient performance, Vought made provisions for a Rocketdyne XLF-40 liquid-fueled rocket motor with 8,000 lbf (35.6 kN) of thrust in addition to the turbojet.

Fly-offs against the Crusader III's main competitor, the future McDonnell Douglas F-4 Phantom II, demonstrated that the Vought design had a definite advantage in maneuverability.

John Konrad, Vought's chief test pilot, later stated that the Crusader III could fly circles around the Phantom II.

[1] In addition, with the perception that the 'age of the gun' was over, the Phantom's considerably larger payload and the ability to perform air-to-ground as well as air-to-air missions, won over Vought's fast but single-purposed fighter.