916 iS A aircraft combustion engine

The Rotax 916 iS A is a turbocharged four-cylinder aircraft piston engine from BRP-Rotax, rated at 160 hp. It is a four-stroke engine with four liquid and air-cooled cylinders, redundant electronic fuel injection and ignition, an intercooler and a propeller speed reduction gearbox, and it is built for light and general aviation aircraft in production.

The key figures are these. Maximum power is 117 kW (160 hp) at 5800 rpm, and maximum continuous power is 101 kW (137 hp) at 5500 rpm. Torque is 193 Nm at 5800 rpm and 175 Nm at 5500 rpm. Displacement is 1352 cm3, from a bore of 84.0 mm and a stroke of 61.0 mm. The maker states full take-off power up to 15,000 feet and a maximum operating altitude of 23,000 feet, which is 7010 m; the turbocharger maintains power as air density drops. Time between overhauls is 2,000 hours.

The engine with the reduction gearbox (ratio 2.54, with overload clutch), turbocharger, intercooler and exhaust system weighs 85.8 kg. The engine suspension frame adds 2.0 kg, the external alternator 3.0 kg and the air guide baffle 0.4 kg, so the installed mass should be summed from these items. Weight and power together give the strong power-to-weight ratio the maker highlights.

The fuel system uses electronic injection with two redundant channels and an engine management system, with an eco mode. Fuel can be gasoline of at least RON 95 or MON 85 (AKI 91 minimum), leaded or unleaded, AVGAS 100LL or ethanol 10 blends. Lubrication is a dry sump with forced circulation, a separate oil tank and hydraulic valve tappets that adjust automatically, which reduces routine maintenance. Starting is by an electric starter in 12 V or 24 V versions. The maker offers an engine configurator for specifying the individual engine.

On certification, the maker labels the iS variants as ASTM compliant and the iSc variants as certified according to EASA CS-E; the product name here is the iS A version, so the applicable approval depends on the variant ordered.

Typical applications are fixed-wing light aircraft and, among certified variants, general aviation airplanes. Large unmanned aircraft and optionally piloted aircraft in a similar power class are a natural fit where a proven injected piston engine with a gearbox is needed.