The E-2 is a high-wing airplane, with one Allison T56 turboprop engine (5250 shp rating) on each wing and retractable tricycle landing gear. As with most carrier-borne airplanes, the E-2 is equipped with a tail hook for recovery (landing) and the nose gear can attach to a shuttle of the aircraft carrier's catapults for launch (takeoff). A distinguishing feature of the Hawkeye is its 24-foot (7.3 m) diameter rotating radar dome (rotodome) that is mounted above its fuselage and wings. This carries the E-2's primary antennas for its long-range radar and IFF systems. No other carrier-borne aircraft possesses one of these. Land-based aircraft with rotodomes include the Boeing E-3 Sentry, a larger AWACS airplane operated by the U.S. Air Force and NATO air forces in large numbers. The similarly-placed stationary radome of the E-2's piston-engined predecessor, the E-1 Tracer, also mandated the E-2's adoption of a modern version of Grumman's long-patented "Sto-Wing" folding wing system, preventing the folded wing panels from making contact with the E-2's rotodome.