AW109

Work on what would become the AW109 commenced during the late 1960s at the Italian helicopter manufacturer Agusta, which sought to design an indigenous rotorcraft suitable for commercial activities. Known as the A109, early designs were of a single-engine helicopter, but the design team revised the project in 1969 to a twin-engine rotorcraft, outfitting it with a pair of Allison 250-C14 turboshaft engines due to market interest in such a configuration. Agusta intentionally placed a low priority on a militarized model, known internally as the A109B, in favor of the eight-seat A109C model. On 4 August 1971, the first of three prototypes performed its maiden flight, though the A109 was subject to a protracted flight testing phase because of dynamic instability that took roughly one year to resolve via a modified transmission design. On 1 June 1975, the type received certification for visual flight rules (VFR) from the Federal Aviation Administration (FAA), permitting the A109 to be operated in North America, and deliveries of production A109s commenced to civil customers in 1976.

Design

The AW109 is a lightweight twin-engine helicopter. Since its introduction, it has undergone several revisions, frequently incorporating advancements in avionics and engine technology. A range of turboshaft powerplants have been utilized, from the original Allison 250-C14 engines to the Turbomeca Arriel 1K1 and Pratt & Whitney Canada PW206 found in more recent models. The engines drive a fully articulated four-blade rotor system, with improvements made over time including composite materials replacing bonded metal in the main and tail rotors to reduce operating costs and noise. The AW109 Power variant features avionics such as a three-axis autopilot, an auto-coupled Instrument Landing System, integrated GPS, Moving Map Display, weather radar, and a Traffic Alerting System. All critical systems are redundant for fail-safe operations, including dual-redundant hydraulic and electrical systems and triple-redundant power inverters.

Armament

A range of armaments can be installed upon the AW109, including pintle-mounted machine guns, machine gun pods, 20mm cannons, rocket pods, anti-tank missiles and air-to-air missiles. Those AW109s operated by the U.S. Coast Guard, later designated as MH-68A, had the following equipment installed: a rescue hoist, emergency floats, FLIR, Spectrolab NightSun search light, a 7.62 mm M240D machine gun and a Barrett M107 semi-automatic 12.7 mm (.50 caliber) anti-material rifle with laser sight.

Operational History

Various branches of the Italian military have operated variants of the AW109, with the Guardia di Finanza employing their own variant since the 1980s for border patrol and customs duties, later replacing their original AW109s with new-generation models. During the Falklands War in 1982, the Argentine Army Aviation deployed three A109As for reconnaissance and liaison, one of which was destroyed on the ground by a British Harrier attack. Two captured A109s were later used by the British Army Air Corps, alongside two additional purchased helicopters, for domestic operations including support for SAS deployments until their retirement in 2009. In 1988, a sale of 46 A109s to the Belgian Armed Forces was overshadowed by a bribery scandal. In early 2013, Belgian AW109s were deployed to Mali for medical evacuation during Operation Serval. The US Coast Guard leased eight armed AW109s, designated MH-68A Sting Ray, for aerial interdiction from 2000 to 2008, which led to arming all its helicopters after the lease expired. The South African Air Force ordered 30 AW109s in 1999, with 25 assembled locally. In 2010, several SAAF AW109s were used for patrol, utility, and medical evacuation during the FIFA World Cup. Twenty AW109s were ordered by the Swedish Armed Forces in 2001, with deployments including anti-piracy missions off the coast of Somalia in 2015. In the Philippines, the Air Force and Navy operate AW109s, with PAF AW109s seeing combat during the Battle of Marawi.

Variants

Main Variants:

• A109A: The initial production model, it was equipped with two Allison Model 250-C20 turboshaft engines and made its first flight on 4 August 1971.

• A109A Mk.II: This was an upgraded civilian version of the original A109A.

• A109BA: Created for the Belgian Army and based on the A109C, this variant featured fixed landing gear, sliding doors, and a tail rotor guard in place of a lower tail fin.

• A109E Power: This was an upgraded civilian version, initially powered by two Turbomeca Arrius 2K1 engines, with a later option for two Pratt & Whitney PW206C engines, both versions retaining the A109E designation and marketed as the AW109E Power.

• A109S Grand: Marketed as the AW109 Grand, this civilian version featured a lengthened cabin, upgraded features, two Pratt & Whitney Canada PW207 engines, and longer main rotor blades with a different tip design compared to the Power version.