Black box in light aircraft ? Affirm !

This is not by design, it is a byproduct of electronic engine management. As the FADEC controls the engine, it knows each and every engine parameter (temperatures, pressures, voltages, …) and monitors all of them.

As a consequence, each time a parameter is out of the normal rage, the FADEC gives an alert to the pilot. This could lead to an apparent higher rate of alerts, but this is only due to the fact that the FADEC has nothing else to do than manage engine and generate alerts.

Can you, as a pilot, pretend that your oil temperature is never slightly above the limit during climb ? Be honest, you cannot monitor constantly all parameters, and the precision of the gauges usually found in light aircraft are not so accurate. Please don’t missunderstand me, I’m not saying that FADEC are generating alerts all the time, or that we never saw parameters on limit values before. The only message is that FADEC helps in detecting transient conditions that could not be noticed with classical (and non-memorizing) gauges.

Thielert even put more safety in its FADEC, as some alerts can not be cleared by the pilot, but only by a mechanic. The flight can be continued, but if such an alarm occurs, the next flight will not be possible. The FADEC will not prevent to start the engine, but obviously no pilot will take-off with a warning on its engine control unit. Would you ?

After any problem, or during periodical maintenance, the mechanics will be able to access all these stored values and parameters. More on that later when I will post on some problems.

As a consequence, in collective flying (club, or shared ownership), some would feel that the FADEC is spying them, and that they could be blamed because of that. This is a purely psychological thing, especially as the pilot can not do anything wrong, except may be switching the FADECs off, or going to IDLE power at an improper time. But in terms of managing the engine, the only thing left is setting power, so how could you do something wrong ?

For maintenance people, this also provides improved way to monitor engine health, as they can follow all parameters over time. So yes, FADEC is a black box, and this is good for anyone.

Bis nächste… tschüss