Rotax 912

Rotax 912 UL
Rotax 912UL 100 hp (75 kW) installation in a 3Xtrim 3X55 Trener
Type Piston aircraft engine
National origin Austria
Manufacturer Rotax Aircraft Engines
Major applications Light sport aircraft
Ultralight aircraft
Variants Rotax 914

The Rotax 912 is a normally aspirated, air- and water-cooled, horizontally opposed four-cylinder, four-stroke, gear reduction-drive engine commonly used on certified aircraft, light sport aircraft, ultralight aircraft and unmanned aerial vehicles.

Contents

Development

The original 80 hp (60 kW) 912 engine has a capacity of 1,211 cc (73.9 cu in) and a compression ratio of 9.1:1. The later 912S is enlarged to 1,352 cubic centimetres (82.5 cu in) and has a compression ration of 10.4:1, yielding 100 hp (75 kW). The 912 A is used in certified aircraft, such as the Diamond DA20, which is quite popular in Europe. The 100 hp (75 kW) versions are used in many light sport aircraft, such as the Flight Design CTSW, the Tecnam P2002 Sierra and the Titan T-51 Mustang. The 80 hp (60 kW) versions are sufficient to overpower the new generation of efficient motorgliders, such as the Pipistrel Sinus and the Urban Air Lambada. It is also fitted to some light twins, such as the Tecnam P2006T.

The engine differs from conventional aircraft engines (such as the Lycoming O-235) in that it has air-cooled cylinders with water-cooled heads and uses a gearbox (PSRU) to reduce the engine's relative high shaft speed (5,800 rpm for 100 hp versions) to a lower speed for the propeller. Lubrication is dry sump, and fuelling is via CV carburetors. These engines have yet to become fuel injected.

The 912 series have a shorter time between overhaul (TBO) than traditional engines but are more fuel efficient than similarly sized engines, e.g., Continental O-200. Effective 14 December 2009, 912 engines have had their recommended Time Between Overhauls (TBO) raised from 1,200 hours to 1,500 hours, or 1,500 hours to 2,000 hours, depending on serial number.[1] In addition to the lower fuel consumption they are certified to run on automotive fuel (mogas) further reducing running costs. The engines are popular in Europe due to the lower fuel consumption and lower generated noise.

Variants

The engine is available in the following versions:

The # in the designation stands for:

  1. Shaft with flange for fixed pitch propeller, P.C.D. 100 mm
  2. Shaft with flange for fixed pitch propeller, P.C.D. 75 mm, P.C.D. 80 mm and P.C.D. 4 inches
  3. Shaft with flange for constant speed propeller P.C.D. 75 mm, P.C.D. 80 mm, P.C.D. 4 inches and drive for hydraulic governor for constant speed propeller
  4. Shaft with flange for constant speed propeller P.C.D. 75 mm, P.C.D. 80 mm, P.C.D. 4 inches and prepared for retrofit of a hydraulic governor for constant speed propeller

Applications

Specifications (Rotax 912 UL/A/F)

General characteristics

Components

Performance

See also

Comparable engines
Related lists

References

External links