The Rolls-Royce Turbomeca RTM322 is a turboshaft engine currently produced by Safran Helicopter Engines. The RTM322 was originally conceived and manufactured by Rolls-Royce Turbomeca Limited, a joint venture between Rolls-Royce and Turbomeca (now Safran Helicopter Engines). The engine was designed to suit a wide range of military and commercial helicopter designs. The RTM322 can also be employed in maritime and industrial applications.
The Safran Aneto is a later development targeted for the super-medium and heavy helicopters, developed by Safran Helicopter Engines covering the 2,500 to 3,000 hp (1,900 to 2,200 kW) range.
The engine first ran on 15 December 1984, with eight bench prototypes for 30,000 cycles and 13,000 test hours, and four for flight tests, initially aiming for type certification to be issued in 1987.[1]
The first order for the RTM322 was received in 1992 to power 44 Royal NavyAugustaWestland Merlin HM1s which subsequently entered service in 1998.[2]
Over 1,100 engines are in service, having logged over one million flight hours, powering 60% of the Agusta-Westland AW101 fleet and 80% of in-service NH90s.[3]
In 2013, Turbomeca (part of the Safran Group, and now known as Safran Helicopter Engines) acquired the entire programme, becoming responsible for both production and product support.[3] Safran Helicopter Engines has since developed a new engine derived from the RTM322, known as the Aneto.
Safran Aneto
Safran Aneto
The first 2,500 shp -1K was selected to power the Leonardo AW149 and Leonardo AW189K twin to extend its capabilities, it flew in March 2017 and was scheduled to be introduced in the fourth quarter of 2018.[4]
The more powerful 3,000+ shp “Dash 3” should appear in the early 2020s and will feature a new compressor and hot section.[5]
The required documentation was expected to be handed to the EASA in early 2019 for a second quarter certification.[6]
By October 2018, the programme had accumulated 4,000 hours, including 105 hours of flight time. In 2018 Sikorsky was considering re-engining its CT7-powered S-92.[7]
The 1,063 kW (1,426 hp) Aneto-1K was added on the RTM 322 type certificate on 12 December 2019.[8]
Design
As an RTM322 variant, the Aneto is a two spool turboshaft with a three stage axial compressor and a single stage centrifugal compressor turning at 36,300rpm, a reverse flow annular combustor, a two stage gas generator axial turbine and a two stage axial power turbine with a forward transmission shaft turning at 21,000rpm. Fitted with an inlet particle separator, its accessory gearbox is driven by the gas generator and the engine is control by a FADEC.[8]
Built upon the Safran Tech 3000 technological demonstrator, it aims to gradually offer up to 15% better fuel economy over current competitors to improve payload-range and offers 25% better power density than existing engines of same volume. Offered for new or for existing models, fewer scheduled maintenance tasks, longer maintenance intervals and health monitoring should improve maintainability.[4]
Suited for 8–15 ton helicopters, it is developed from the RTM322: the -1K has a similar architecture but no common parts. Parts made by additive manufacturing are used in the gyratory combustion chamber and the inlet guide vane system. Compatible with hybrid and distributed propulsion systems, in cruise flight one of the two engines could be shut down and restarted when needed. In the AW189, it is offered along the incumbent General Electric CT7, needing minor changes to the top-deck structure and engine cowls. Exempted from U.S. International Traffic in Arms Regulations, it could power the AW189's military derivative, the AW149 or a future attack helicopter based on its dynamic systems.[5]
Developed from a French Aviation Authority study, the Safran Power Pack Eco Mode on the Airbus Helicopters Racer allows it to shut down one of engines in cruise, lowering fuel consumption by 15%, and quickly and automatically reactivate it with an electric starter to its maximum power for acceleration, landing or emergencies.[9] The Aneto specific fuel consumption should be 10% better than the competing CT7s.[6]
