French general-aviation engine manufacturer Société des Motorisations Aéronautiques (SMA) has started developing an uprated version of its 230hp (170kW) SR305-230 diesel-cycle engine as it embarks on an ambitious expansion plan in the USA.

The company started work on an uprated four-cylinder engine, the 300hp (225kW) SR305-300, six months ago and the Jet A-fuelled powerplant has begun bench tests at its facilities in Bourges, outside Paris. The new engine, which required little architectural modification and small changes to the fuel injection system, should be certificated by mid-2006, says SMA vice-president for customer services Miriam Dunn.

SMA is also in talks with US Mooney engineering specialists to add the M20 Eagle to its growing list of pending retrofit approvals. The Snecma/EADS/ Renault joint venture is targeting the M20 as part of its drive to enter the US market through its Frederick, Maryland-based subsidiary SMA Engines, says Dunn. "If you'd asked me a year ago about prospects in the USA, I would have said there is no interest in diesel. But now the concept of diesel pistons is proved, coupled with a growing fear over the disappearance of avgas [aviation gasoline] and there is a growing interest."

Despite less difference in price between avgas and Jet A in the USA than in Europe, high users of piston singles are attracted not only by the reduced fuel burn of the engine, but also enhanced performance, safety and lower downtime. SMA is aiming to capture around 15-20% of the total piston retrofit market in the USA over the next 10 years, with 70% of its forecast production rate of 200 engines per year destined for the US market, says Dunn.

Following certification of the SR305-230 engine on the Cessna 182, SMA is currently conducting more than 400h of demonstration flights throughout Europe. SMA currently has 600 orders for the €92,000 ($110,000) engine, and has delivered 17 to date.

SMA expects to sign a deal with a Mooney modification centre to start work on a supplementary type certificate (STC) "within weeks", says Dunn. In addition to the M20, SMA says STCs for the Piper Dakota PA-28 should be completed by the end of the year, while STCs for the Cessna 172, EADS Socata TB20 Trinidad and Piper PA-34 twin are also under way. The company is also working with Cirrus Design, Vulcanair, Maule and Akkord to become an original equipment supplier for turbo-diesel variants of their aircraft.



Source: Flight International