The Griffin HT1 is used as an advanced flying-training helicopter at the Defence Helicopter Flying School (DHFS) at RAF Shawbury, in Shropshire, and the Search and Rescue Training Unit (SARTU) at RAF Valley, in Anglesey. There are eleven aircraft in service; eight are based at RAF Shawbury and three are based at RAF Valley. The Griffin HT1 is a military twin-engined helicopter derived from the civilian Bell Textron 412EP helicopter and is powered by two Pratt & Whitney turboshafts rated at 1800shp. The aircraft has an advanced, composite material, fourblade main rotor system, and pendulum dampers on the rotor hub to reduce vibrations at higher cruise speeds. The composite main-blades can be interchanged and folded easily for storage.
With a cruising speed of 120kts (138mph) and an endurance of almost 3 hours which makes it ideally suited for advanced helicopter training, the Griffin HT1 is ideally suited for Multi-engine Advanced Rotary Wing (MEARW) training, which is completed over a period of 34 weeks on No 60(R) Squadron at RAF Shawbury. The syllabus includes general-handling flying, underslung-load carrying, night-vision goggle training, procedural instrument flying, formation flying, low-flying navigation and an introduction to tactical employment, including operations from confined areas. A short SAR-procedures course, which includes elements of mountain flying and maritime rescue winching, is conducted at RAF Valley. However, students who are finally streamed for SAR flying duties on completion of their advanced helicopter training return to SARTU to complete an extended SAR course prior to joining the Sea King Operational Conversion Unit at RAF St Mawgan.
In addition to pilot training, the Griffin is used for crewman training: a very important and integral part of multi-crew operations. A Griffin simulator, with full motion capability and an advanced graphics suite, is also based at RAF Shawbury and is a fully integrated part of the MEARW course. It is especially useful for procedural instrument-flying training and practising complex emergency-handling techniques. The Griffin, which has now been in service with DHFS for five years, is also used in its HAR2 form by No 84 Squadron on SAR duties in Cyprus.
- Crew: 1-2 pilots
- Capacity: up to 13 passengers, maximum external load of 4,500 lb (2,040 kg)
- Length: 56 ft 1 in (17.1 m)
- Rotor diameter: 46 ft (14.0 m)
- Height: 15 ft (4.6 m)
- Disc area: 1,662 ft² (154.4 m²)
- Empty weight: 6,789 lb (3,079 kg)
- Max. takeoff weight: 11,900 lb (5,397 kg)
- Powerplant: 2 × Pratt & Whitney Canada PT6T-3BE Twin-Pac turboshafts, 900 shp (671 kW) each
- Fuselage length: 43 ft (13.1 m)
- Maximum speed: 140 knots (161 mph, 259 km/h)
- Cruise speed: 122 knots (140 mph, 226 km/h)
- Range: 402 nmi (463 mi, 745 km)
- Service ceiling: 20,000 ft (6,096 m)
- Rate of climb: 1,350 ft/min (6.86 m/s)
- Power/mass: 0.2663 hp/lb (437 W/kg)