V-22 Osprey

Design

The V-22 is a dual-piloted, twin engine, medium-lift, tilt-rotor aircraft that combines the speed, range, and fuel efficiency of a turboprop aircraft with the slow flight and hover capabilities of a helicopter. Its design incorporates advanced, but mature technologies in composite materials, fly-by-wire flight controls, digital cockpits, survivability, airfoil design, and manufacturing.

The airframe is constructed primarily of graphite-reinforced epoxy composite material. The composite structure would provide improved strength to weight ratio, corrosion resistance, and damage tolerance compared to typical metal construction. Battle damage tolerance is built into the aircraft by means of composite construction and redundant and separated flight control, electrical, and hydraulic systems. An integrated electronic warfare defensive suite including a radar warning receiver, a missile warning set, and a countermeasures dispensing system, would be installed.

The V-22 fuselage has a number of advanced composite structures. A rear loading ramp has been incorporated, which when closed, comprises the lower portion of the aft fuselage section. There is one side-entry personnel door. The fuselage is a semi-monocoque structure that connects the wing, nacelles, landing gear, sponson, ramp and empennage. External skin, bulkheads, and stringers are primarily constructed of carbon/epoxy with some metallic and fiberglass skin panels. Cabin floor panels are honeycomb sandwiches. Frames are constructed of either aluminum or carbon/epoxy.

The empennage consists of a horizontal stabilizer and two vertical stabilizers. The construction is a semi-monocoque design using predominantly carbon/epoxy composite material. The fuselage-to-empennage attachment is accomplished by an integrated design consisting of two retainer pin assemblies. Loss of a single retainer is failsafe under a reduced flight load regime. Horizontal-to-vertical stabilizer attachment is accomplished by dual composite/aluminum angle assemblies at both forward and aft stabilizer spars. Each attachment assembly consists of one upper and one lower angle fitting, only one of which is required to maintain integrity of the vertical stabilizer.

The horizontal stabilizer consists of two spars that extend and mechanically attach at each end to the vertical stabilizer. Thirteen ribs are located chordwise. The vertical stabilizer consists of two spars, which coincide with the two horizontal stabilizer spars. Nine ribs are located chordwise.

The wing structural assembly consists of (1) the wing torque box, and (2) the pylon, support structure. The wing torque box primary structure consists of forward and aft spars, ribs (18 in total), and upper and lower skin panels with co-cured stringers. The wing tip ribs are machined aluminum forgings and have provisions for mounting the conversion spindle, the conversion actuator spindle, and the pylon downstop fittings. The pylon support structure consists of the transmission adapter, pylon support fitting, and the conversion spindle. The conversion spindle along with the conversion actuator and downstop provides the structural support between the pylon support structure and the wing.

The V-22 power plant (designated T406-AE-1107), auxiliary internal fuel capacity, and an aerial refueling capability give the V-22 the ability to self-deploy worldwide. Two 6150 shaft horsepower turboshaft engines each drive a 38 ft diameter, 3-bladed proprotor. The proprotors are connected to each other by interconnect shafting which maintains proprotor synchronization and provides single engine power to both proprotors in the event of an engine failure. The engines and flight controls are controlled by a triply redundant digital fly-by-wire system.

Changes necessary to convert the basic assault troop transport configuration for other missions would be simple and easily accomplished by organizational level maintenance personnel in field and shipboard environments.