DA 42 accident

"Cary" wrote in message
oups.com...
The problem, as I understand it, was the battery was dead. According
to the POH, the battery is used to start the engine and is used as a
backup during flight for all the electronic gear (including the
FADEC). Although the investigation is still ongoing and other answers
may be forthcoming, when they operated the landing gear they exceded
the power available from the alternators and the backup system (the
battery) was not available so the FADEC (engine computers) stopped.
One of the lessons here is that one should not fly an airplane that
relies on electricity if you don't have a battery to run the
electricity!

Cary

On Apr 23, 4:35 pm, wrote:
Gig 601XL Builder wrDOTgiaconaATsuddenlink.net wrote:

Neil Gould wrote:
A simple voltmeter with a "red line" should suffice, along with a
caution; "Don't take off with the needle outside the green arc". Of
course, that won't prevent someone from insisting on making a bad
decision.

I again agree but if you are going to have an sytem with FADEC it ought
to
have the authority to to clearly tell you that it is about to use its'
authority to shut the engine off.

From the description it sounds more like the FADEC didn't have the
authority (or power) to do anything.

More to the point, if all the power goes away, what happens to all
the "settings" the FADEC controls?

Do they go to zero, full, stay where they are?

It appears that they go to zero, which is a damn unhandy failure mode.

--
Jim Pennino

Remove .spam.sux to reply.



Even if the battery worked fine, something that causes damage, even
something as small as a bird strike can cause a short; dropping voltage,
and shutting down the engines, plural. Wouldn't a relay that isolated the
engine when the buss voltage dropped to zero have helped? Surely some
prioritizing is in order.

Al G