DA 42 accident

Recently, Cary posted:

The message came as a PDF file. I don't think I can post such a file
to the newsgroup, so if you would like to see the file, let me know
where to send it.

No need, at this point. I was mainly curious about whether Diamond
addressed the risk of taking off or flying with low voltage?

Neil

"Cary" wrote in message ...
The message came as a PDF file. I don't think I can post such a file
to the newsgroup, so if you would like to see the file, let me know
where to send it.


Some pdf readers come with a SELECT TEXT TOOL icon in the tool bar. Switch
to this mode and you can copy and paste text in pdf doc like normal.

Neil Gould schrieb:
Recently, Friedrich Ostertag posted:

Karl-Heinz Kuenzel wrote:
Hi.

Here in Germany we had an accident with a brand new DA 42 in Speyer
(EDRY) on 3-4-07 during take off.

It seems, that the battery was down and both engine were started with
remote power.
After take off when retracting the gear, the props feathered and both
engines stopped.

You can read about that accident in German (sorry) in
www.pilotundflugzeug.de

First hearing about that accident and the background, I could not
believe it.
I don't even know where to start. How can an aircraft, that depends on
electrical power for the operation of it's engines, be airworthy
without fully redundant electrical systems? While in this particular
case the pilot might have noticed the problem, had he meticuously
follow procedures and started the second engine at the plane's own
power, it is quite easy to find failure modes that would go unnoticed
inflight, yet cause double engine failure at the instant the gear is
lowered on final. Lead batteries are known to occasionally go flat
suddenly, once the buildup of oxide makes contact between the lead
elements. Happened to me in the car once. The engine (a diesel with
mechanical injection pump) ran happily without me even noticing the
failure until I shut it down. When I turned the power back on again,
not even the lights in the dashboard would light up, it was
completely and utterly dead.

I would never have thought that they cut corners like that at
Diamond. I Hope this will not create a lot of mistrust in
aerodiesels, as it is not a diesel issue. I guess you could call it a
FADEC issue if you wanted, however it really is an issue of
redundancy of essential systems, and easily solveable as such.

I have a somewhat different take on this event. It appears to me that the
pilot didn't sufficiently understand his aircraft or the implications of
the symptoms he observed. Knowing that there was insufficient power to
start the engines, that the engine & prop controls were dependent on
electric power and that the landing gear used an electric motor would have
stopped me from taking off until the battery/electrical system problem was
addressed. I don't find it surprising that the props feathered in this
situation, and would even say that it would be the expected behavior,
rather than a fluke of some kind. I would find it surprising if Diamond
doesn't have adequate information about their flight systems in the POH to
inform the pilot of this possibility.

Regards,

Neil




OK Neil.

You find it in the article.

POH - Under - abnormal operating procedures - 4B.7 STARTING ENGINE WITH
EXTERNAL POWER - #13 Opposite engine ..... START WITH NORMAL PROCEDURE

That is it.

Karl

Recently, Karl-Heinz Kuenzel posted:

Neil Gould schrieb:
I have a somewhat different take on this event. [...]
I don't find it
surprising that the props feathered in this situation, and would
even say that it would be the expected behavior, rather than a fluke
of some kind. I would find it surprising if Diamond doesn't have
adequate information about their flight systems in the POH to inform
the pilot of this possibility.


OK Neil.

You find it in the article.

My Deutsch is far too rusty to find it in the article. ;-)

POH - Under - abnormal operating procedures - 4B.7 STARTING ENGINE
WITH EXTERNAL POWER - #13 Opposite engine ..... START WITH NORMAL
PROCEDURE

That is it.

That's fine for starting the engines, but that isn't the only issue, is
it?

Is there nothing in the POH about the electrically powered items (landing
gear, FADEC, etc.)? If there is, it shouldn't require an EE degree to
realize that one should be concerned about the condition of the batteries,
charging, etc. if one has to "jump start" the engine, or to realize that
something critical is in need of attention.

Maybe I'm just an overly cautious type. ;-)

Neil

Neil Gould wrote:
Recently, Karl-Heinz Kuenzel posted:

Neil Gould schrieb:
I have a somewhat different take on this event. [...]
I don't find it
surprising that the props feathered in this situation, and would
even say that it would be the expected behavior, rather than a fluke
of some kind. I would find it surprising if Diamond doesn't have
adequate information about their flight systems in the POH to inform
the pilot of this possibility.


OK Neil.

You find it in the article.

My Deutsch is far too rusty to find it in the article. ;-)

POH - Under - abnormal operating procedures - 4B.7 STARTING ENGINE
WITH EXTERNAL POWER - #13 Opposite engine ..... START WITH NORMAL
PROCEDURE

That is it.

That's fine for starting the engines, but that isn't the only issue,
is it?

Is there nothing in the POH about the electrically powered items
(landing gear, FADEC, etc.)? If there is, it shouldn't require an EE
degree to realize that one should be concerned about the condition of
the batteries, charging, etc. if one has to "jump start" the engine,
or to realize that something critical is in need of attention.

Maybe I'm just an overly cautious type. ;-)

Neil

I agree that if you are flying what is basically an all electric aircraft
and you have an electrical problem on the ground that you should take extra
care before flight BUT, there should be some system in place that doesn't
allow the gear switch, landing lights or any other electrically operated
item to become an OFF switch with out some damn significant warning.

Recently, Gig 601XL Builder wrDOTgiaconaATsuddenlink.net posted:

Neil Gould wrote:
Recently, Karl-Heinz Kuenzel posted:

Neil Gould schrieb:
I have a somewhat different take on this event. [...]
I don't find it
surprising that the props feathered in this situation, and would
even say that it would be the expected behavior, rather than a
fluke of some kind. I would find it surprising if Diamond doesn't
have adequate information about their flight systems in the POH to
inform the pilot of this possibility.


OK Neil.

You find it in the article.

My Deutsch is far too rusty to find it in the article. ;-)

POH - Under - abnormal operating procedures - 4B.7 STARTING ENGINE
WITH EXTERNAL POWER - #13 Opposite engine ..... START WITH NORMAL
PROCEDURE

That is it.

That's fine for starting the engines, but that isn't the only issue,
is it?

Is there nothing in the POH about the electrically powered items
(landing gear, FADEC, etc.)? If there is, it shouldn't require an EE
degree to realize that one should be concerned about the condition of
the batteries, charging, etc. if one has to "jump start" the engine,
or to realize that something critical is in need of attention.

Maybe I'm just an overly cautious type. ;-)

Neil

I agree that if you are flying what is basically an all electric
aircraft and you have an electrical problem on the ground that you
should take extra care before flight BUT, there should be some system
in place that doesn't allow the gear switch, landing lights or any
other electrically operated item to become an OFF switch with out
some damn significant warning.

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.

Neil

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.

Recently, Gig 601XL Builder wrDOTgiaconaATsuddenlink.net posted:

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.

We may be describing the same elephant from different sides. ;-)

Neil

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.

On 2007-04-23 13:44:11 -0700, "Gig 601XL Builder"
wrDOTgiaconaATsuddenlink.net said:

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.

The FADEC cannot tell you anything or control anything if it doesn't
have power. There would be warning systems, but all they would tell you
is that your engines have quit. :-)

The problem is not FADEC. It is pilot error -- taking off with a known
electrical problem in an airplane dependent on electricity to fly,
coupled with a poor understanding of how an alternator works.
--
Waddling Eagle
World Famous Flight Instructor