DA 42 accident

On 2007-04-24, Al G wrote:
Well said. It should have some fall back. If the coffee maker shorts the
engines quit?

No, a breaker pops.

Personally, I'm more interested in the accident investigation - all we
know at the moment is the pilot had a discharged battery and the engines
quit.

How do we know that there were not two systems that were failed on the
aircraft - such as the backup generator (which has been mentioned) as
well as the battery? We don't until the accident investigation
concludes.

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"Dylan Smith" wrote ...

Personally, I'm more interested in the accident investigation - all we
know at the moment is the pilot had a discharged battery and the engines
quit.

Here's some mo
http://www.flightglobal.com/Articles...ngine-row.html

"Snowbird" wrote ...

"Dylan Smith" wrote ...

Personally, I'm more interested in the accident investigation - all we
know at the moment is the pilot had a discharged battery and the engines
quit.

Here's some mo
http://www.flightglobal.com/Articles...ngine-row.html


WOW, great link! Tech details down to millisecond voltage dip measurements.
Hurray for the Poor Man's Black Boxes on those Thielerts. Reading this has
tipped me to beginning my research on getting a Graphic Engine Analyzer with
data logging. I only wish I had done this last week at SNF.

Snowbird wrote:
"Dylan Smith" wrote ...

Personally, I'm more interested in the accident investigation - all
we know at the moment is the pilot had a discharged battery and the
engines quit.

Here's some mo
http://www.flightglobal.com/Articles...3371/accident-
ignites-da42-engine-row.html

Well at least neither Diamond nor TAE is saying there is no problem and
trying to blame the pilot. This is an excellent first step in getting any
problem fixed.

On Apr 24, 3:47 pm, "Mike Isaksen" wrote:
wrote in message ...
That is, while the FADEC itself probably doesn't require much
in the way of power, how much power does it take to manipulate
the throttle, mixture, and prop?

The answers to those kind of questions seem to be missing from the public
record, and even the public discussion. [..]

We had a large discussion of FADEC right here last November.
Unfortunately, non-engineer types decided to hijack the discussion,
mostly because they wanted to bash anyone who agreed with Mxsmanic
that all-electronic systems can have major failure modes. (Ever have
your car engine stop because of a failed sensor? I have.)

At that time, I wrote "Losing all power (including the battery backup)
on a FADEC means your engine stops."

Multiple people (who I will not name because they should rightfully be
embarrassed, but they post here a lot) threw insults at the very idea
that this could happen.

In any case, the FAA deems that EECs (Electronic Engine Controllers)
should fail such that the engine is producting at least 85% power.
EECs are just engine aids, however. Full authority FADECs have no
such requirement. Instead, they are supposed to have backup
batteries and/or alternators. Just like the DA-42, basically.

Regards, Kev

Gig 601XL Builder wrote:
Snowbird wrote:
"Dylan Smith" wrote ...

Personally, I'm more interested in the accident investigation - all
we know at the moment is the pilot had a discharged battery and the
engines quit.

Here's some mo
http://www.flightglobal.com/Articles...3371/accident-
ignites-da42-engine-row.html

Well at least neither Diamond nor TAE is saying there is no problem and
trying to blame the pilot. This is an excellent first step in getting any
problem fixed.


As a DA42 owner I hope that the "problem" will get fixed by either
Diamond or TAE. However, note that Diamond did blame the pilot because
the pilot did not use the procedures outlined in the POH to start the
second engine.

Cary

Jim,

but I would hope the new technology offered by FADEC would begin to
eliminate those SPOFs without introducing new ones.

That's pretty much impossible by definition. Not even NASA does it on
spacecraft.

It appears to me that we
still have all of the legacy SPOFs and have now added new ones.

I disagree.

--
Thomas Borchert (EDDH)

On 2007-04-26, Kev wrote:
We had a large discussion of FADEC right here last November.
Unfortunately, non-engineer types decided to hijack the discussion,
mostly because they wanted to bash anyone who agreed with Mxsmanic
that all-electronic systems can have major failure modes. (Ever have
your car engine stop because of a failed sensor? I have.)

I've had more older car engines stop because of failed mechanical
ignition parts like points. I've never actually had a car engine with an
ECU fail.

I know a pilot who had a double magneto failure, too, which resulted in
the C172 on its back in a field. Guess what - most two magneto engines
have single points of failure.

It's not a question that FADECs will fail - but what will be more
failure prone: a manual-everything engine where the pilot can mismanage
the engine into quitting, or a FADEC that can lose electrical supply and
cause the engine to quit. Only time will really tell in aviation which
is more reliable. However, my bet on having owned both cars with purely
mechanical ignition and cars with engine management computers is that
the ones with engine management computers are orders of magnitude more
reliable. I would at this stage be putting my bets on FADEC being more
relibale than purely mechanical engines + manual engine management in
the long run. That's not to say FADECs won't fail, but pilots+mechanical
electrical systems will fail more often.

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"Dylan Smith" wrote in message
...

I know a pilot who had a double magneto failure, too, which resulted in
the C172 on its back in a field. Guess what - most two magneto engines
have single points of failure.


What caused the mags to fail?

On 2007-04-26, Maxwell wrote:
What caused the mags to fail?

I don't remember the specifics (and I'm trying to find the NTSB report
with no joy so far). I believe it was one of those 'dual mag'
installations and there was a mechanical failure.

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