AgustaWestland is continuing to refine the configuration of its developmental AW169 helicopter, as the Anglo-Italian airframer pursues certification for the 4.5t type in the second half of 2014.

Recent modifications to the flight-test aircraft include the addition of a pair of fairings atop the engine cover aft of the main rotor mast. One of them – dubbed the "horse's collar" – runs along the edge of the cover, while the second, a comb-shaped component, sits immediately aft of the mast. The fairings are designed to prevent tail shake through changing the path of the rotor wash.

The exhaust ports have additionally been turned outboard by 10˚ to prevent overheating of a section of the AW169's composite tail boom. This temperature anomaly manifested itself on the port side of the tail during lateral flights or with crosswinds in hot conditions, says the manufacturer.

Recent test milestones have included the completion of climatic chamber trials, where the AW169 was subjected to temperatures ranging from -40˚C to 55°C, and hot weather testing carried out using the third flight-test prototype in Cordoba, Spain.

The same aircraft will shortly be sent to an as-yet undecided location, likely to be Alaska, for cold and high trials, with a further prototype used to carry out single-engine flight evaluations, says AgustaWestland.

In all the fleet has accumulated around 470h of flight testing, with a further 500h on a single ground-test vehicle.

The aircraft's performance has been well received by its test pilots, says the airframer, particularly its power during hot and high tests.

Initial tests revealed fuel consumption some 2% worse than expected from its twin Pratt & Whitney Canada PW210A powerplants, says AgustaWestland. However, the engine manufacturer has since modified the combustion chambers of the turboshafts, and they are producing "better than expected" fuel consumption.

Although final assembly of the new helicopter will be carried out at Vergiate in Italy and Philadelphia in the USA, AgustaWestland's Yeovil, UK plant will play a role in its development through production of rotor blades and transmission components. Data gathering from edge-of-envelope manoeuvres will also be carried out at the UK facility.