Managing engines a better way
When Teledyne Continental Motors, and its subsidiary Aerosance, announced a $9,995 introductory price for its Powerlink full authority digital engine control (FADEC) system at AOPA Expo in Palm Springs, California, last October, general aviation entered a new era.
TCM's FADEC engine management system is a huge step forward for GA — now pilots can fly with both hands instead of reserving one hand, and half their brain, for recalling and implementing arcane powerplant management procedures.
Why FADEC for GA?
"Powerlink FADEC will eventually be available for almost every GA aircraft powered by Continental or Lycoming engines," said Aerosance President Steve Smith.
Anyone who remembers the headaches of trying to balance the right amount of choke and throttle pumping required to get a cold automobile engine running smoothly should appreciate the ease that TCM's Powerlink FADEC brings to airplane engine operation.
We are still using manual engine management techniques in general aviation. TCM is betting that GA pilots are ready for a better way. Its FADEC system constantly optimizes the fuel-air mixture and ignition timing of each cylinder from engine start to shutdown.
The fuel injectors
Each FADEC system fuel injector is a fully variable, solenoid-controlled pulsed unit. The timing and duration that each injector is opened is microprocessor controlled. This allows the FADEC computers, which constantly monitor the exhaust gas temperature (EGT) and cylinder head temperature (CHT) of each cylinder, to meter the exact amount of fuel for the most efficient operation at all power settings and operating conditions for that cylinder.
System components
There is an electronic control unit (ECU) for each pair of cylinders. Each ECU contains a microprocessor circuit board, the high-voltage coils that fire the spark plugs, the spark-plug wire towers, and plug-in connections to the low-voltage wiring harness.
The harness consists of three parts — a series of sensors that gather engine data such as throttle position, manifold air temperature, fuel pressure, cylinder head temperature, exhaust gas temperature, and engine speed information; a leg that connects to the health status monitor (HSM), aircraft electrical bus, and the backup power system; and a series of legs that connect to the injector coils.
The backup electrical power system can be either a separate battery (the one under the pilot's seat of TCM's demonstrator airplane, a Beechcraft A36 Bonanza, has enough capacity to power the FADEC system for up to an hour and a half) or a second engine-driven alternator.
On the instrument panel you see a 2-by-2-inch black square — that's the health status annunciator (HSA). You test that and the standby battery during your runup to make sure that the system is in "go" condition.
The start and flight
There's no red-knobbed mixture control projecting from the panel. FADEC takes care of all those flight engineer tasks. During takeoff and other high-power operations, the mixture at each cylinder is automatically set to best power, which translates to 80 to 100 degrees Fahrenheit rich of peak. After power is set for )limb, the mixture is again automatically adjusted. Economy cruise mixture settings are lean of peak. TCM says installation of the FADEC system will cut fuel consumption by 5 to 15 percent.
If a CHT or EGT rises above a certain temperature, the microprocessor controlling the fuel flow to that cylinder overrides the predetermined mixture and adjusts the pintel valve opening to increase the fuel flow, thus cooling the hot cylinder. The mixture to the other cylinders isn't affected.
During a flight with TCM pilot Phillip Grice, I watched a laptop computer display from the copilot's seat as the FADEC system maintained exact mixture settings on each cylinder. It worked perfectly.
The system is fully redundant and gathers engine data that can be stored or electronically sent to TCM for troubleshooting assistance.
TCM says that the Powerlink FADEC protects a pilot's investment in his expensive engine, and gives turbinelike operation and durability to piston aircraft engines.
FAA approval has been obtained for Beechcraft Bonanzas, with the STCs for the IO-550-powered Beechcraft Baron and Cessna 210-series airplanes promised soon. Eventually, Powerlink FADEC will be available for most GA airplanes through additional STCs. Can you state any better SFC or engine reliability numbers?
Price: $9,995 introductory price
Contact: 860/409-7880; www.fadec.com
E-mail the author at [email protected].
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