The G.91 is equipped with a swept wing, which uses an all-metal two-spar structure; the outer panels can all be detached for transportation or easy replacement, while the center section is integral with the fuselage. It is swept at a 37-degree angle at quarter-chord with a thickness-to-chord ratio of 10 per cent. The wing features single-slotted flaps and hydraulically-actuated ailerons. The tailplane is electrically actuated and had irreversible hydraulic elevators fitted with an artificial feel system as well as hydraulically-actuated air brakes and a drogue parachute located at the base of the rudder for rapid deceleration.