GAPA (Ground-to-Air Pilotless Aircraft)

Two GAPA missiles prepare to launchImmediately after World War II, the GAPA (Ground-to-Air Pilotless Aircraft) was the first Boeing missile and pioneered the company's efforts in rocket-propulsion technology. GAPA was a slim, two-stage missile that traveled at supersonic speeds.

Its mission was to intercept aircraft flying up to 700 mph at altitudes of 8,000 to 60,000 feet. GAPA was tested using both solid- and liquid-fuel rockets, as well as ramjet propulsion systems. The first flights used early radar guidance systems. Later versions had a target seeker and used solid-fuel rockets in combination with ramjet power.

Nov. 15, 1949, a GAPA reached 59,000 feet, the highest altitude for a supersonic ramjet of the time. Although it was never used as a defensive weapon, GAPA provided the basis for Bomarc missiles.

Specifications
First flight: Jan. 13, 1946
(first stable flight: July 18, 1946)
Model number: 600 to 602
Classification: Missile
Length: 16 feet
Diameter: 10 inches
Booster weight: Up to 6,000 pounds
Top speed: 1,500 mph
Ceiling: 59,000 feet
Power: Rockets, ramjet engine