As the potentially lucrative piston engine replacement market emerges, UK manufacturer Diesel Air has entered the fray, with plans to produce a diesel engine family aimed at the general aviation market.

The 75kW (100hp) DAIR 100 is the first in a 75-450kW engine range. It has completed more than 1,000h of flight testing on an Airship Technologies blimp as part of an evaluation of a vectored thrust propulsion unit for installation on future airships.

"We have been working for two years to provide the next generation of aero engines for light aircraft of the 21st century. The diesel engine offers the best specific fuel consumption of any prime mover, with the two-stroke cycle giving the best efficiency in that class," says Diesel Air managing director, David Soul.

According to the Olney, Buckinghamshire-based company, the liquid-cooled DAIR 100 consumes 4.5litres (1.2USgal)/h less diesel than a typical gasoline engine, at a cruise speed of 75kt (140km/h), and at a substantially lower fuel cost. "The 100hp engine resembles a flat four or boxer engine, but has only two cylinders, each with two pistons. It has two outboard crankshafts connected by gears to the propeller drive and accessories," adds Soul. The engine is designed to replace the Teledyne Continental and Textron Lycoming pistons.

Diesel Air is to design and build a more powerful 335kW engine for Airship that will also be aimed at the large general aviation and small airliner retrofit market. Certification is planned by the fourth quarter of next year.

• UK engine builder Wilksch Airmotive, developing its new CITEC diesel aero engine family, has had a major boost with a £300,000 ($483,900) UK Department of Trade and Industry research and development grant. The three-cylinder WAM-120, installed in a Europa light aircraft, was unveiled at the 2-4 July Popular Flying Association rally at Cranfield, UK.

Source: Flight International