Mistral Engines is not the first start-up to try to break the general aviation power duopoly enjoyed by Teledyne Continental and Lycoming, but the tiny Swiss company believes its normally aspirated rotor design - based on the original Wankel engine - will be able to provide the industry with a step-change in reliability and efficiency.

Not that taking on two established US manufacturers with a long GA heritage is simple. Thielert attempted it with a diesel powerplant, but issues over maintenance forced the German company into insolvency last year, although it is still trading. Geneva-based Mistral has had its difficulties, too. Founded as long ago as 2001 by private investors, it still does not have a product on the market.

Problems raising new capital forced the company in late July to slow certification efforts for its debut 300hp (520kW) engine - which can burn standard unleaded petrol or avgas - and lay off half of its 22-strong workforce. European and US approval for the G-300 is not likely until the second half of 2010.

 © Mistral Engines
Mistral is taking aim at the light aircraft retrofit market with its G-300


However, the company was at the AirVenture show in Oshkosh a week later to promote itself to the all-important North American GA community. There, chief executive Philippe Durr, recruited last September from the energy and utilities sector, was bullish about what Mistral can offer.

"While there have been great leaps in avionics and other areas in recent decades, this is the first product that is genuinely new in engines. There was an attempt to bring in diesel technology, but the reliability is not yet so good," he says.

The company is targeting the supplemental type certificate retrofit market for aircraft such as the Cessna 206 and 210, the Beech Bonanza and Baron, the Cirrus SR22, all powered by Lycoming or Continental original equipment. Durr says a number of maintenance providers have submitted letters of intent to fit the engine under an STC and that with "the OEMs all aware of us" an eventual factory-fit deal is not out of the question.

The Mistral engine, says Durr, has the advantage of being simple, with just three moving parts; reliable, with a targeted interval between overhauls of 3,000h compared with the usual 2,000h; and with a power to weight ratio that makes it ideal for heavy use, he adds. A 15% price premium over rivals is more than compensated for by a cost of ownership that is up to 30% lower, he argues.

Developed in the 1950s by German engineer Felix Wankel and developed in the automotive industry over the years in various forms, the original Wankel engine was driven by a rotating motion rather than reciprocal pistons. The now open technology was used as the basis for the Mistral engine.

The six investors have injected more than $20 million into Mistral and recently earmarked another $1.5 million to keep the business going. However, Durr says the current economic situation has made it hard to secure the external finance needed to launch full-scale production.

Mistral wants to offer new investors equity in the company. "There is considerable interest out there and we are in the middle of the process, but the downturn has slowed things down," he says. An inability to "maintain our burn rate" led to the redundancies, although Durr is confident that most of the workers will be rehired. "Certification is still very much our target next year, but it will probably be the latter part of 2010," he says.

As well as the 300hp version, the company plans a 200hp version, aimed at the light sport and experimental aircraft categories. Turbocharged versions of both, planned for 2011, will take power up to 230hp and 360hp respectively, opening the door to the piston-powered helicopter market, says Durr.

The company is also looking further afield, signing a memorandum of understanding at the Paris air show with Abu Dhabi Airports to develop a facility in the planned aerospace cluster at Al Ain airport.

Durr has a simple answer to the question of why no-one else has come up with a product in decades if rotary technology is so simple: "This is a market dominated by a duopoly and duopolies are not the best way to develop innovation," he says.

Source: Flight International