Maule Air is working on a diesel-powered version of its M-7 five-seat short take-off and landing light aircraft. The new version, designated the MX-9-230, will be powered by a 170kW (230hp) SR-305 engine burning Jet A kerosene. The four-cylinder engine is produced by SMA, a joint venture of EADS, Renault and Snecma.

Moultrie, Georgia-based Maule has installed the engine in an M-7 and is preparing to begin flight tests. Certification is expected to take about a year, says technical advisor David Wright. The company has begun to take orders for the aircraft, which is priced at around $200,000, with deliveries to begin immediately after certification.

Wright says overseas interest in the diesel-powered aircraft is strong "because 100LL [aviation gasoline] is getting hard to come by". Additionally, the SMA-powered MX-9 "will be one of the most fuel-efficient aircraft Maule has offered", he says. Fuel consumption is expected to be around 34litre/h (8-9USgal/h) compared with 57litre/h on a similar petrol engine.

The MX-9 will also introduce a gross-weight increase to 1,270kg (2,800lb), compared with the MX-7's 1,135kg, and is planned to be available with a range of Textron Lycoming gasoline engines in addition to the SMA diesel-cycle engine,Wright says. Maule, meanwhile, is completing certification work on a version of the MX-7 powered by a 150kW Franklin gasoline engine produced in Poland by PZL.

Source: Flight International