Development of the RTM 322 across four helicopter programmes Rolls-Royce Turboméca's collaborative RTM 322 turboshaft engine programme came into its own in 1997, with development under way for four different helicopter projects.

The success is a tribute to the successful collaboration between the UK and French engine makers, which has stretched back over 30 years, but also to the family design philosophy that has allowed the engine to meet different power requirements within the same basic structure.

Engines for the Royal Navy's EH Industries EH-101 Merlin are rated at a baseline 1,650kW (2,200shp). The first 40 have already been delivered out of the 154 on order for the maritime helicopter programme.

The RTM 322 is on order for the EH101s going to the RAF, but these have been uprated to nearly 1,800kW. The UK has also selected the RTM 322 for its Boeing WAH-64 Apache attack helicopter contract and the first two engines were shipped in 1997 for prototype aircraft.

The latest application is on Europe's collaborative NH90 venture, with engine shipments due early this year and qualification scheduled for 1999. This required power of 1,860kW from each engine, achieved with an increased flow compressor.

The same basic hardware can achieve 2,050kW and the company is looking at developments to take it up to 2,600kW.

Other design features include a 30% reduction in the number of parts against similar turboshafts. Full digital electronic control was also considered as an integral part of the design from the start of the project.

Source: Flight International