The flight deck accommodates the pilot and co-pilot. The pilots have the Honeywell Primus II digital radio communications system with dual transponders. The flight deck instrumentation includes a Honeywell SPZ-4500 fully digital automatic flight control system with a AH-600 attitude and heading reference system (AHRS), an AZ-810 air data computer . The flight data is displayed on a Honeywell EDZ-805 electronic flight information system four or five-tube display.The fuselage is of semi-monocoque fail-safe design constructed of aluminium alloy. The cabin can be configured in a 10 seat VIP layout, as a 16 seat executive airliner or as a 29 or 30 seat commuter aircraft. The passenger door on the port side at the front of the cabin is fitted with integral airstairs. The cabin is air conditioned with a Normalair Garret air conditioning system. The aircraft is very quiet and internal noise is minimised because the propeller to fuselage distance has been increased from that of the J31 design.The two Honeywell (formerly Allied Signal) TPE331-14GR/HR turboprop engines, with a takeoff rating per engine of 1,650shp, drive the McCauley five-bladed constant speed feathering metal propellers. The engine intakes have an air-bleed anti-icing system and a two-bottle fire extinguishing system is installed in the engine nacelles. The propellers are fitted with an electrical de-icing system. The typical fuel burn, 420kg fuel /hour is between 20 and 40% lower than that of previous generation engines giving the aircraft a fully passenger loaded range of 1,430km. The J41 aircraft is fitted with a Smiths engine management system.