Graham Warwick/WASHINGTON DC
Unison Industries and Precision Airmotive have teamed to develop electronic mixture-control (EMC) for piston aircraft. It combines electronic ignition-control with automatic mixture-leaning to increase engine fuel-efficiency and power while reducing pilot workload.
The development is based on Unison's LASAR engine-control system and Precision's RSA fuel injector. The LASAR microprocessor controls ignition timing and drives fuel-mixture control valves in the throttle body. These provide automatic fuel metering through venturi air-density compensation.
"LASAR with EMC automatically leans or enriches the fuel mixture based on flight conditions and power settings, and automatically switches to manual mixture control in the event of an aircraft electrical system malfunction," Unison says.
Flight and engine tests are scheduled to be completed by the first quarter of 1998, leading to roll-out of the first production LASAR with EMC by the second quarter. Unison and Precision will market and support the system jointly and are targeting both new-aircraft and retrofit markets.
Unison's LASAR engine-control system is now available on Textron Lycoming 320- and 360-series four-cylinder and 540-series six-cylinder piston aero-engines. The LASAR was first introduced in 1995, for the 320-series, and was certificated for the 540-series in late October, in response to a "high level of demand" for the system on six-cylinder engines.
Electronic engine-control improves starting, general operation and fuel efficiency, taccording to the company.
Source: Flight International
