Rolls-Royce Turbomeca RTM322
| Company type | Joint venture |
|---|---|
| Industry | Aerospace, Turboshaft engines |
| Predecessor | Rolls-Royce, Turbomeca |
| Founded | 1980s |
| Fate | Taken over by Safran Helicopter Engines in 2013 |
| Headquarters | United Kingdom / France |
| Products | RTM322 turboshaft engine, Safran Aneto engine |
| Parent | Safran Helicopter Engines (since 2013) |
The Rolls-Royce Turbomeca RTM322 represents a turboshaft engine developed by Safran Helicopter Engines. Initially created through the collaboration of Rolls-Royce Turbomeca Limited—a partnership between Rolls-Royce and Turbomeca—the RTM322 was engineered to serve a broad range of military and civilian helicopter platforms, as well as maritime and industrial sectors.
The Safran Aneto is an enhanced iteration designed specifically for super-medium to heavy helicopter categories, offering power outputs in the range of .
Development
Conceived to rival engines such as the General Electric T700 and Pratt & Whitney Canada PW100, the RTM322 was aimed at platforms including the Hughes AH-64 Apache and the Sikorsky UH-60 Blackhawk. The development budget of £100 million was equally divided between partners; Rolls-Royce was responsible for manufacturing the turbine, combustor, and inlet particle separator, while Turbomeca handled production of the axial-centrifugal compressor and intake system.
The engine's maiden run occurred on 15 December 1984, followed by comprehensive bench testing involving eight prototypes that completed 30,000 cycles and accumulated 13,000 hours of testing. The goal was to achieve type certification by 1987.
The first procurement took place in 1992 with an order for 44 Royal Navy AugustaWestland Merlin HM1 helicopters, which entered operational service in 1998. To date, over 1,100 RTM322 engines are active worldwide, collectively surpassing one million flight hours. They power approximately 60% of the AgustaWestland AW101 fleet and constitute 80% of all operational NH90s.
In 2013, Turbomeca—now operating as Safran Helicopter Engines—assumed full control of the program, taking over production and support functions. Since then, Safran has advanced the Aneto engine as the RTM322’s successor.
Safran Aneto
The initial -1K variant delivering 2,500 shp was selected to power the Leonardo AW149 and Leonardo AW189K. It first flew in March 2017 with plans for introduction by late 2018. A more potent “Dash 3” model exceeding 3,000 shp—with redesigned compressor and hot section—is anticipated in the early 2020s. Certification documentation was scheduled for submission to the EASA in early 2019, targeting certification during Q2 of that year. By October 2018, testing had reached 4,000 hours including 105 flight hours. Sikorsky explored replacing the General Electric CT7 on its S-92 with the Aneto.
The Aneto-1K variant was incorporated into the RTM322 type certificate on 12 December 2019.
Design
Evolving from the RTM322 architecture, the Aneto is a two-spool turboshaft featuring a three-stage axial compressor coupled with a single-stage centrifugal compressor spinning at 36,300 rpm. It utilizes a reverse flow annular combustor, a two-stage gas generator axial turbine, and a two-stage axial power turbine rotating at 21,000 rpm. The engine includes an inlet particle separator and an accessory gearbox driven by the gas generator shaft; engine management is handled via FADEC.
Derived from Safran’s Tech 3000 demonstrator platform, the Aneto aims to improve fuel efficiency by up to 15% compared to competitors—enhancing payload-range capabilities—and offers a power density increase of roughly 25% over similarly sized engines. It is suitable for both new helicopter designs and retrofit applications, featuring reduced scheduled maintenance intervals alongside health monitoring systems to boost reliability.
Targeted at helicopters weighing between eight and fifteen tons, the -1K variant shares overall design principles with the RTM322 but incorporates entirely new components without common parts. Additive manufacturing techniques are applied in key elements such as combustion chambers and inlet guide vanes. The engine supports hybrid propulsion concepts and distributed power architectures; during cruise phases one engine can be shut down and restarted when necessary. On platforms like the AW189, it is offered alongside the incumbent GE CT7 with minimal airframe changes. Not subject to U.S. International Traffic in Arms Regulations (ITAR), it can equip military models such as the AW149 or future attack helicopters based on its dynamic system capabilities.
Originating from a French Aviation Authority study, Safran’s Power Pack Eco Mode implemented on the Airbus Helicopters Racer allows one engine to enter standby during cruise flight—cutting fuel use by approximately 15%—with rapid automatic restart via electric starter for acceleration or emergency maneuvers. The Aneto demonstrates about a 10% improvement in brake-specific fuel consumption relative to competing GE CT7 engines.
Applications
- AgustaWestland Apache
- AgustaWestland AW101
- NHIndustries NH90
- Also integrated into the Eurocopter X3
Aneto
- Leonardo AW149
- Leonardo AW189K: Aneto-1K variant delivering 2,500 shp; maiden flight occurred in March 2017, with service entry in the fourth quarter of 2018.
- Considered for the Airbus Helicopters X6 program (currently on hold)
- Airbus Helicopters Racer high-speed demonstrator powered by Aneto-1X, rated at 2,500 shp.
- Indian Multi Role Helicopter equipped with Aneto-1H
Specifications
| Variant | RTM322-01/1 | RTM322-01/9 | Aneto-1K |
|---|---|---|---|
| Type | Turboshaft | ||
| Compressor | Three axial stages combined with one centrifugal stage | ||
| Combustor | Reverse flow annular design | ||
| Turbine | Two-stage high-pressure turbine plus two-stage power turbine | ||
| Length | 1,171–1,181 mm (46.1–46.5 in) | ||
| Diameter | 615–708 mm (24.2–27.9 in) | ||
| Dry weight | 255 kg (562 lb) | 232 kg (511 lb) | 260 kg (570 lb) |
| Take-off power | 1,611 kW (2,160 hp) | 1,611 kW (2,160 hp) | 1,063 kW (1,426 hp)[lower-alpha 1] |
| Gas generator speed | 36,300 rpm | ||
| Power turbine speed | 20,900 rpm | 20,841 rpm | 21,000 rpm |
| Power:weight ratio | 6.1 kW/kg (3.7 hp/lb) | 6.9 kW/kg (4.2 hp/lb) | 4.1 kW/kg (2.5 hp/lb) |
| BSFC | 0.420 lb/(hp⋅h) (0.255 kg/kWh) | ||
External links
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