On the eve of the official unveiling of its new X4 medium-class rotorcraft, Airbus Helicopters has sensationally ditched one of the two engine suppliers on the programme and hinted at a heavier aircraft than previously thought.

The medium-twin X4 was initially proposed with a choice of either Pratt & Whitney Canada PW210E or Turbomeca Arrano powerplants, both in the 1,100shp (809kw) range – but now the former engine has been dropped.

Airbus Helicopters says that following a “comprehensive market assessment” it will move the positioning of the new aircraft “consequently necessitating a significant engine power increase”.

That is thought to mean the X4 will be larger than the 4.3t AS365 or 4.9t EC155 it is slated to replace, bringing it closer to the 6.4t AgustaWestland AW139 which uses 1,600shp-rated P&WC PT6 engines.

As such, Airbus Helicopters will not work with P&WC to develop a “growth version” of the PW210E. Turbomeca has always given the power rating on its all-new Arrano turboshaft as between 1,100-1,300shp.

However, the maiden sortie of the X4 – due to be launched on 3 March at the forthcoming HAI show in Orlando – may still be with the P&WC engine, given the development timeline of the Arrano.

Patrick Moncoutié, Arrano programme vice-president at the French engine manufacturer, says discussions on sole sourcing have been taking place since last year. In return it has given a commitment to Airbus Helicopters to accelerate the pace of the new powerplant “to be ready for first flight [of the Arrano] as soon as possible”.

That milestone was originally envisaged for 2016, but Moncoutié says that may now come this year. “With a single-source scenario, we save at least six months.”

However, he points out that a power increase cannot be delivered at the same time as advancing its development.

Certification of the engine is likely to be achieved by the end of 2017, ahead of service entry of the X4 in 2018.

Source: FlightGlobal.com