6039 Twin Arm Launcher is a Castle set of the Crusaders faction released in 1988. The set contains 73 pieces and instructions to build a double-armed catapult, a horse and two Crusader soldiers.
A lightweight, double-armed black catapult was the subject of 1987's 6039 Twin Arm Launcher set. The hinged, "finger-powered" catapult arms on the four-wheeled rig hurled 1x1 yellow bricks as ammunition, and was manned by two Crusaders knights, one on horseback.
This was the first Castle Set to include a barding covering for the horse.