High Quality Content by WIKIPEDIA articles! The Boeing GA-1 (company designation Model 10) were armored triplanes. Designed in 1919, it was powered by a pair of modified Liberty engines driving pusher propellers. The first of the Engineering Division`s heavily-armored GAX series (ground attack, experimental) aircraft, the ponderous airplane was intended to strafe ground troops while remaining immune to attack from the ground as well as from other enemy aircraft. It was so well armored its five-ton weight proved excessive.