Bell Helicopter Academy: 407 training

[EN48]

FADEC fail procedures (summary)

There are several "classes" of FADEC failures, and only one requires significant pilot action in flight. If the FADEC detects a major failure, it switches from "AUTO" mode to "MANUAL" mode uncommanded by the pilot. In this case, the Academy teaches to use collective and throttle in a coordinated manner to avoid an underspeed or overspeed. In the worst case for an overspeed (on the ground in the FLY detent with flat pitch) when the FADEC fail horn sounds, immediately roll the throttle to idle. The RFM talks about first matching NG on the throttle bezel to NG on the gage, and this is a good idea, but it seems in many cases things happen too fast for this, and you need to do something right away with the collective and or throttle. The flight insdtructors did not emphasize matching NG indications until after engine speed was unders some control. This falure mode is a "land as soon as practical" pilot action.

All other FADEC failures require no significant pilot action in flight: fly non aggressively and land as soon as practical. The FADEC remains in AUTO mode, but with some reduced capability.

ADDENDUM: The acft I used for training has FADEC software version 5.356 (latest version) installed, which includes a second FADEC channel supporting a reversionary governor. This was not discussed in any detail in the training, but it is my understanding that with this software, some faults that previously resulted in a reversion to MANUAL mode now cause the FADEC to remain in AUTO, with less possibility of an overspeed/underspeed induced by the pilot.

And Old Skool is quite right: reduce the throttle to idle before lowering the collective or it may get expensive. (If you do a run on as recommended, you will have some collective in on the ground; if you arrive at a hover, wind the throttle down to land, dont lower the collective until at idle.)

Despite all the "issues," the FADEC is your friend.