Big Things Coming

By Nadav Eiron, ANN correspondent

Teledyne Continental has had FADEC in the works for a while, but lately more and more actual hardware starts showing up. On display at Oshkosh this year were two new FADEC conversions for existing airplanes on display in the TCM tent: a Cirrus SR-22 installation developed in-house by TCM, and a Piper Malibu installation by Malibu Power and Propeller.

While the Malibu STC is still quite far out, contingent on the certification of a new variant of the TSIO-550 engine by Continental, sources close to TCM tell us the SR-22 project is in the very final stages before certification.

The FADEC system in the SR-22 controls fuel flow into the engine, and spark timing. Propeller RPM is still controlled separately, by a conventional hydraulic governor. However, the mixture knob is gone from the cockpit.

The system uses a pulse modulated electronic fuel injection system and an electronic ignition system. System inputs include temperature measurements (EGT and CHT) from each individual cylinder, RPM, throttle position, and crankshaft position.

Under the cowl are three boxes, each housing two separate FADEC computers that control two cylinders. During normal operations, each of the two computers inside the box controls a cylinder, while monitoring the data for the other cylinder controlled by the box. (File Photo of Engine)

If one of the computers fails, the other computer can take over control of the second cylinder as well. Since engine functions now depend entirely on an electrical power source, FADEC installations require two completely redundant sources of power.

The Cirrus's dual bus design makes this relatively easy. The FADEC system is fed by both the main bus and the essential bus. The STC will also include a second 70 amp alternator that will be able to support all the aircraft's systems, including FADEC, if the primary alternator fails.

Other than simplifying engine management, the FADEC system also enables performance improvements. While fuel savings are expected, our sources tell us that the more noticeable improvement is in available power. We were told that the FADEC equipped SR-22 test plane "consistently beats Cirrus's POH numbers". Performance is improved most notably in climb.

Reliability and maintainability is also expected to be improved with FADEC. The system records all airplane parameters for future analysis. Several levels of analysis are planned: mechanics can download data to a laptop or PDA in what is referred to as 'Level 2 Analysis' that is meant to aid in basic troubleshooting and maintenance of the engine.

'Level 3 Analysis' is through an upload of the engine information to TCM's website for long-term trend analysis. 'Level 4 Analysis' combines level 3 data with additional data such as oil analysis and compression tests that are entered manually.

At the opposite end of its product range, TCM also introduced the LSA (as in Light Sport Aircraft) version of the venerable O-200 engine. The LSA version, while still producing the same 100HP that the regular O-200 puts out, is designed to be lighter-weight and lower-cost.

Weight reduction comes from somewhat lighter structure, and use of some "automotive-like" parts, such as spark plugs. TCM is planning to offer the LSA O-200 through OEMs only, either in completed airplanes or as parts of LSA kits. Development and certification of this engine is "moving rapidly" according to our sources.

FMI: www.tcmlink.com