AgustaWestland AW609

The AgustaWestland (now Leonardo) AW609, formerly the Bell/Agusta BA609, is a twin-engined tiltrotor VTOL aircraft with a configuration similar to that of the Bell Boeing V-22 Osprey. It is capable of landing vertically like a helicopter while having a range and speed in excess of conventional rotorcraft. The AW609 is aimed at the civil aviation market, in particular VIP customers and offshore oil and gas operators.

The AW609 is a tiltrotor aircraft capable of performing vertical landings whereas conventional fixed-wing aircraft cannot, allowing the type to serve locations such as heliports or very small airports, while possessing twice the speed and the range of any available helicopter. AgustaWestland promotes the type as "...combining the benefits of a helicopter and a fixed-wing aircraft into one aircraft". The AW609 appears to be outwardly similar to the military-orientated V-22 Osprey; however, the two aircraft share few components. Unlike the V-22, the AW609 has a pressurised cabin. As of 2013, multiple cabin configurations have been projected, including a standard nine-passenger layout, a six-to-seven-passenger VIP/executive cabin, and a search and rescue model featuring a hoist/basket and four single seats; medevac and patrol/surveillance-orientated variants has also been proposed. For increased passenger comfort, the cabin is both pressurised and equipped with soundproofing. Access to the cabin is via a 35-inch-wide (89 cm), two-piece clamshell door center-set into the fuselage underneath the wings.

The AW609 is powered by a pair of Pratt & Whitney Canada PT6C-67A turboshaft engines, which each drive a three-bladed proprotor. These engines possess roughly twice the horsepower of the similarly sized AgustaWestland AW169 helicopter. Both of the engine and proprotor pairs are mounted on a load-bearing rotatable pylon at the wing's ends, allowing the proprotors to be positioned at various angles. In helicopter mode, the proprotors can be positioned between a 75- and 95-degree angle from the horizontal, with 87 degrees being the typical selection for hovering vertically. In airplane mode, the proprotors are rotated forward and locked in position at a zero-degree angle, spinning at 84% RPM. The flight control software reportedly handles much of the complexity of the transitioning between helicopter and airplane modes; automated systems also serve to guide pilots to the correct tilt angle and air speed settings.

When flying in airplane mode, the majority of lift is produced by the AW609's wings, which are slightly forward-swept. Both the wing and the main fuselage are made largely of composite materials. The 34-foot-long (10 m) wings feature flaperon control surfaces which are normally automatically controlled; in vertical flight, the flaperons drop to a 66-degree downwards angle to reduce the wing area being encountered by downwash from the proprotors. A high-mounted rudderless vertical stabiliser is attached the rear of the fuselage to stabilise flight while in aircraft mode. In the event of a single engine failure, either engine can provide power to both proprotors via a drive shaft; the AW609 is also capable of autorotation. The AW609 has been designed to develop Full Transport Category/Class 1 performance to operate safely even when flown under single engine conditions. It is equipped with a de-icing system, and is to be certified for flying into known icing conditions. Building on experiences with the V-22, the AW609 is outfitted with a sink rate warning system.

Avionics include a triple-redundant digital fly-by-wire flight control system, a head-up display system, and Full Authority Digital Engine Controls (FADEC). The cockpit has been designed so that the AW609 can be flown by a single pilot in instrument flight rules conditions. Several of the aircraft's controls, such as blade pitch, are designed to resemble and function like their counterparts on conventional rotorcraft, enabling helicopter pilots to transition to the type more easily. Elements of the aircraft's controls feature touchscreen interfaces. Shortly following AgustaWestland's full acquisition of the program, a substantial modernisation of the AW609's design was initiated in 2012; these changes included new engines and the redesigning of the cockpit. As part of the design refresh, new flight management systems, Northrop Grumman inertial and GPS navigation systems, and various other avionics from Rockwell Collins were adopted.