For sure the sexiest block of wood at AirVenture is the TurbAero mock-up of their all-new, clean sheet design turbine engine. The new company is dedicated to filling a hole in the market for a 200 hp turbine engine, with follow-up derivatives rated at 320 hp and 120 hp emerging in that order.
TurbAero sees turbine power for general aviation as a potential game changer and they have answers to the two usual turbine stumbling blocks of cost and high fuel burn. For cost they point to a design life of 10 years or 3000 hours before overhaul, which means a competing piston engine would have to factor in at least one expensive overhaul to match.
Taming the turbine’s inherently fierce fuel burn rate also figures into TurbAero’s calculus. Here their pivotal technology for an everyman’s turbine is a heat exchanger called a recuperator. It passes the engine’s exhaust flow in close proximity to the intake air so what would otherwise be waste heat is transferred into the incoming air stream, increasing combustion efficiency. Not normally seen on aviation turbines, such power recovery devices are typical on larger, stationary turbines.
The result, says TurbAero, is a small turbine that—in the long haul—banks near zero maintenance costs, lower fuel prices and a fuel burn thought to be within 1.5 gallons per hour of an equivalent piston engine against an admittedly higher initial cost. TurboAero is using a projected $80,000 retail price for their engine in their calculations.
There are other considerations. Turbines love altitude and the TurbAero engine is being engineered for cruising above the usual piston heights paying the inherent speed and fuel economy dividends of flying high.
While assembly of production engines is eventually planned in the U.S., TurbAero’s team is somewhat international, with the chief engineer and corporate headquarters currently in Adelaide, Australia. To date the major engineering effort has gone into developing the recuperator and the propeller gearbox. Detail design of the recuperator, which is integral to the engine and features carefully sized and shaped titanium “micro channels,” has so far taken the last two years, while the original spur gear gearbox was more recently abandoned in favor of a planetary unit.
TurbAero’s Chief Technology Officer, the instantly likable Ali Mahallati explained how sizing the recuperator is a tedious case of juggling materials and mainly airflow paths to find the sweet spot between recuperator efficiency versus back pressure on the power turbine, a job still underway. Testing of individual turbine parts is finished, and when the recuperator is ready the engine will begin testing as a complete system. TurbAero estimates another six months before putting their first turbine on a test stand, followed by another year before production engines are available.
TurbAero has a newly built Arion Lightning airframe standing by for flight testing, but they also foresee a bush plane and go-fast cross country machine in their flight testing future.
Attending AirVenture to introduce their company, TurbAero has a definite start on the ambitious hope of bringing light, powerful turbine power to the masses.