Groen Brothers Aviation (GBA) is to certificate the turbine-powered version of its four-seat gyroplane ahead of the originally planned piston-engined aircraft. It cited greater demand for the Hawk 4T variant powered by a Rolls-Royce 250 turboshaft.
The US Federal Aviation Administration has required GBA to submit a new certification application, but will allow work already done on the piston version to be "rolled into" the turbine programme, says the Salt Lake City, Utah-based company.
The piston-powered prototype is being re-engined and will join the Hawk 4T test aircraft, which first flew in July. Two conforming prototypes are being built and certification flight testing is planned to begin early next year.
GBA believes it can develop the Hawk 4T on the schedule drawn up for the piston version, with certification expected late next year or early 2002.
The company says most of the dealers and customers who placed deposits on almost 150 gyroplanes have switched their orders to the turbine version, despite the increase in price - a Hawk 4T costs $749,000 compared with $295,000 for the piston version.
Source: Flight International
