The current 230 hp version SR305-230E designed for the general aviation market, specifically for jet fuels aircraft, has been certified by EASA and FAA in 2011 The SR305-230E is intended for OEM's integration programs. It is designed for single or multi-engine application, and for professional as well as private use.

The SR305-230E offers the following advantages: use of jet fuels available around the world, fuel cost savings by over 30% compared to Avgas engines, optimized aircraft operation, and no lead exhaust.

  • Four cylinders
  • Certified ceiling : 20,000 ft
  • Critical altitude : 10,000 ft
  • Constant speed of propeller : 2,200 rpm

The SR305-230E has been selected by Cessna for the Turbo Skylane JT-A, as well as by Odessa aircraft plant (Ukraine) for the DELFIN aircraft.

In order to meet market needs, SMA is currently studying more powerful version of the current engine.

View the SR305-230E Brochure.



SMA SR305-230

The SMA SR305-230 is an air/oil-cooled, horizontally-opposed, four-cylinder, Jet-A1 piston aircraft engine. The engine is manufactured by SMA Engines, a French company. The engine is offered as a conversion package for the Cessna 182 P, Q and R

The engine first flew in a Socata TB-20 in March 1998 and was officially introduced at the Paris Air Show in June 1998. French DGAC approval was attained in July 2001 with FAA certification following a year later. Between 17 and 25 July 2006 a converted Cessna 182 (registration F-GJET) flew from Le Bourget to Oshkosh, Wisconsin.



The SMA SR 305-230-1 is a four-cylinder, horizontally-opposed turbocharged direct fuel injection diesel engine. The engine installation includes an electronic central processing unit (CPU) which continually calculates the proper fuel/air mixture. If this unit fails completely during flight, the mechanical backup position is selected and the pilot can control the fuel/air mixture as required to complete the flight.

Full-throttle operation at sea level is at 90 inches of manifold pressure. Unlike most other aircraft engines (which recommend the maximum power setting be used only for five minutes during the initial takeoff stage), the SR 305 can be operated indefinitely at this setting, although normal cruise uses around 70 inches and economy cruise uses around 60 inches.

The STC conversion on the Cessna 182 includes a new cowl, both to accommodate the different engine dimensions and to provide the required cooling airflow. Belly-mounted cowl flaps are still used, but less cooling airflow is directed over the cylinder barrels and more cooling airflow is directed into side-mounted oil coolers. About one-third of the engine cooling is provided by airflow over the cylinders; the remainder is provided by engine oil. The engine's oil distribution system routes a large oil flow to hot zones in the cylinder heads and upper cylinder barrels, carrying the heat away to the oil coolers.

As of early 2008, SMA had provided over 50 conversion packages (the installation is usually performed by other companies, not SMA). Most of those conversions were performed in Europe, with less than a dozen having been performed in North America.


Performance Cessna 182 with SMA SR305-230:

C182 P and Q
C182 R