DA-42 Double Engine failure
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DA-42 Double Engine failure
Sorry guys need a bit of help here....looking for some info on the DA-42 that had a double engine failure after T/O due to electrical failure( from memory ). I have tried the search engine but can't seem to get any feedback. Thanks in advance!
Happy Landings,
Oz_TB10
Happy Landings,
Oz_TB10
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Jaba and I talked to a Fugro guy at Esperance last year about the DA-42, when we were retrieving the FTDK from Perth.
Seems they had had some "unusual" interactions with the electrical systems of the aircraft as well.
Jaba may remember the details.
Dr
Seems they had had some "unusual" interactions with the electrical systems of the aircraft as well.
Jaba may remember the details.
Dr
Last I heard that failure was caused by running the battery flat on the ground, then using external power to start it. When they took off, there wasnt enough power to run the engine computers AND retract the gear.
Have also heard some interesting stories regarding mobile phones and FADEC engines...
Have also heard some interesting stories regarding mobile phones and FADEC engines...
Fugro's 'unusual interactions' with the electronics in the aircraft are more related to the 'unusual equipment' they put into their aircraft, and less related to it being a Diamond. Methinks you'd get the same curiosities with any FADEC system.
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There is more to the story...
The Avweb article is a little old and is does not mention the most embarrassing part for the pilots.
They started both engines with ground power, yes, which was then and still is expressly forbidden in the flight manual.
Since the alternators are capable of supplying power to all flight systems and to retract the gear as well, it appears that the dead battery must have been drawing quite a bit of current as well. I speculate that the pilots must not have noticed the excessive load on the alternators before take-off.
Given the rest of the story as told (engines failed etc), it is a bit of a shame that the manufacturer copped the blame. As I see it, disobey the flight manual = trouble. In any aircraft, not just a Diamond.
Diamond & Thielert argued about it, apparently because the engines were supposed to be designed to remain running despite a 50ms power interruption to the ECU's. The argument was that Diamond said "but this was only a 20ms interruption! Your fault!" while Thielert said "but this is not quite precisely the type of interruption specified - how could we plan for this? Your fault!" **
To cut a long story short, there are now backup ECU batteries for each engine which will last around half an hour or so in the event of every other electric source failing. So it is now a little safer to go flying without bothering to read the boring old flight manual.
** This is a paraphrase of the actual argument, which no doubt ran for several dozen paragraphs.
They started both engines with ground power, yes, which was then and still is expressly forbidden in the flight manual.
Since the alternators are capable of supplying power to all flight systems and to retract the gear as well, it appears that the dead battery must have been drawing quite a bit of current as well. I speculate that the pilots must not have noticed the excessive load on the alternators before take-off.
Given the rest of the story as told (engines failed etc), it is a bit of a shame that the manufacturer copped the blame. As I see it, disobey the flight manual = trouble. In any aircraft, not just a Diamond.
Diamond & Thielert argued about it, apparently because the engines were supposed to be designed to remain running despite a 50ms power interruption to the ECU's. The argument was that Diamond said "but this was only a 20ms interruption! Your fault!" while Thielert said "but this is not quite precisely the type of interruption specified - how could we plan for this? Your fault!" **
To cut a long story short, there are now backup ECU batteries for each engine which will last around half an hour or so in the event of every other electric source failing. So it is now a little safer to go flying without bothering to read the boring old flight manual.
** This is a paraphrase of the actual argument, which no doubt ran for several dozen paragraphs.
So, basically it wouldn't have happened to a pair of good old fashioned Lycomings or Continentals with conventional magnetos.
Chalk one up for "old technology"
Chalk one up for "old technology"
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I think Lasio is on the money...more a matter of the stuff they install.
He did mention it was always a kee ear on things as at the level they fly at, on glitch and you're in a ditch!
J
He did mention it was always a kee ear on things as at the level they fly at, on glitch and you're in a ditch!
J
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Why 5mins?
So why has CASA allowed the 5mins Back-up Battery as compared to going with the obviously safer 30mins ? Or does this not concern CASA at all?
As for the argument about the older twins, how many other new light twins options are there in the market nowadays? Was thinking about it when FTA decided to get 6 ( or 7) to replace the Duchess. Not many options me thinks.
( Sorry if i sound a bit naive but i have held a CPL for less than 6 months)
Oz_TB10
As for the argument about the older twins, how many other new light twins options are there in the market nowadays? Was thinking about it when FTA decided to get 6 ( or 7) to replace the Duchess. Not many options me thinks.
( Sorry if i sound a bit naive but i have held a CPL for less than 6 months)
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Cap'n Arrr..
What issues have you encounted with the FADEC's and mobiles. Kinda wanna know this, as i am in these things daily, often forgetting to turn the mobile off in my haste.
Operating outside the scope of the Flt Manual with a new AC is asking for trouble. You guys in aussie still popping cylinders?
What issues have you encounted with the FADEC's and mobiles. Kinda wanna know this, as i am in these things daily, often forgetting to turn the mobile off in my haste.
Operating outside the scope of the Flt Manual with a new AC is asking for trouble. You guys in aussie still popping cylinders?
Haven't had any experience myself (theres part of the flight manual that says TURN OFF ALL ELECTRONIC DEVICES, I figure I'll follow it)
BUT I have been told that CASA test pilots have seen it, and I know someone who had it demonstrated to them in a DA40 diesel (with fadec etc) that putting the phone in the right spot can cause surges and other nasties. It was done on the ground, but it did affect it. Not sure how serious it gets, but I'm one of those better safe than sorry people.
As far as I was aware the Aussie diamonds had 30min backup, thats what I've been told the one I fly has.
BUT I have been told that CASA test pilots have seen it, and I know someone who had it demonstrated to them in a DA40 diesel (with fadec etc) that putting the phone in the right spot can cause surges and other nasties. It was done on the ground, but it did affect it. Not sure how serious it gets, but I'm one of those better safe than sorry people.
As far as I was aware the Aussie diamonds had 30min backup, thats what I've been told the one I fly has.
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Very interesting playingup - thanks for the post. I wonder which SB our ones use? Have to go and check...
Regarding
Obviously safer? Not so obvious to me. Remember that the accident that sparked this discussion involved an electrical interruption lasting much less than one second. The engines can take power from either alternator or the main battery, so you need a fairly major (unique, statistically unlikely, involving gross carelessness) event to cause problems for more than several tens of milliseconds. Five minutes would seem adequate.
Now if I was on an oceanic delivery flight, I'd be tempted to take a 24V truck battery up with me as backup... But that's a different story.
Cheers,
O8
Regarding
So why has CASA allowed the 5mins Back-up Battery as compared to going with the obviously safer 30mins ?
Now if I was on an oceanic delivery flight, I'd be tempted to take a 24V truck battery up with me as backup... But that's a different story.
Cheers,
O8
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"So, basically it wouldn't have happened to a pair of good old fashioned Lycomings or Continentals with conventional magnetos. Chalk one up for old technology" T'is the nature when you venture from the proven norm... There is a reason you have 2 magnetos on pistons, same reason why they are still used today, not to mention other added advantages such as weight. Seems we have forgotten this, eh? Just because a modern car is more complex with fancy electronix and other monitoring crap; than these small piston aircraft, doesn't mean we should try and make them like modern cars...lesson not well learned it seems. A real diesel has no 'sparking plug' or electronix, just a thought.
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Diamond days
The gear Fugro carries in the diamonds is passive, ie it doesn't transmit anything.
I heard that a "problem developed on an overseas job as well , one engine stopped and partial power on the other.
They tend to have mishaps on a regular basis , so maybe the aircraft isn't at fault.
MC
I heard that a "problem developed on an overseas job as well , one engine stopped and partial power on the other.
They tend to have mishaps on a regular basis , so maybe the aircraft isn't at fault.
MC
I have heard of at least two occasions of the NZ based DA 42's having engines shut themselves down in flight for no good reason.
On one occasion I was told that the shutdown occurred on a flight where issues with the engine management system for one engine were being investigated when the "Good" engine shut down. A very hurried return to base from what I hear.
The other occasion resulted in a prompt landing at the nearest suitable airfield after 3 of the four engine computers shut down leaving just one operative engine with it's solitary management system.
They evolved from a glider so I guess they would have a good glide ratio.
On one occasion I was told that the shutdown occurred on a flight where issues with the engine management system for one engine were being investigated when the "Good" engine shut down. A very hurried return to base from what I hear.
The other occasion resulted in a prompt landing at the nearest suitable airfield after 3 of the four engine computers shut down leaving just one operative engine with it's solitary management system.
They evolved from a glider so I guess they would have a good glide ratio.
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The only uncommanded engine shut downs I have been involved with were all but one preceded by fluctuating or surging rpm.
Any sign of surging RPM on a DA42 needs to be investigated by the techies, specifically to look for damaged wiring, loose plug, corroded connector pins on the prop valve. Cleaning the prop valve plug pins and giving them a gentle squeeze to ensure a good contact cures a lot of these problems.
It is caused by intermittent contact, when connection fails the prop starts to feather, when connction is re-established it returns to normal operation. with a loose pin or chaffed wire this shows up as a surging as the prop changes pitch. If it is ignored the result is the prop will eventually feather and stop the engine.
TAE did have a slightly dodgy prop valve supplied by a subcontractor a while back but these should all have been changed out by now.
If the engineers make sure the harness cannot chaffe and the pilots operate it within the parameters of the FM then we have few problems.
And yes the back up batteries are a back up, back up for pilots who fly with a flat battery. You would need to loose alternators and the main battery before the back up system was required.
Any sign of surging RPM on a DA42 needs to be investigated by the techies, specifically to look for damaged wiring, loose plug, corroded connector pins on the prop valve. Cleaning the prop valve plug pins and giving them a gentle squeeze to ensure a good contact cures a lot of these problems.
It is caused by intermittent contact, when connection fails the prop starts to feather, when connction is re-established it returns to normal operation. with a loose pin or chaffed wire this shows up as a surging as the prop changes pitch. If it is ignored the result is the prop will eventually feather and stop the engine.
TAE did have a slightly dodgy prop valve supplied by a subcontractor a while back but these should all have been changed out by now.
If the engineers make sure the harness cannot chaffe and the pilots operate it within the parameters of the FM then we have few problems.
And yes the back up batteries are a back up, back up for pilots who fly with a flat battery. You would need to loose alternators and the main battery before the back up system was required.
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To quote a fellow PPRuNeR: "Holy thread resurrection Batman!"
But 27/09 it's not quite as bad as you say. There have been cases of wiring faults causing multiple ECUs to report themselves as failed but in most cases there was no actually failure. As alarming but as harmless as a failed OP gauge on a Lycoming. There was a genuine failure a few months ago - perhaps that's the one you're referring to
I'm quite looking forward to hearing how the Austro engines work in practice. As Generation 2 engines (albeit from a start-up engine manufacturer) they should have significant improvements.
But 27/09 it's not quite as bad as you say. There have been cases of wiring faults causing multiple ECUs to report themselves as failed but in most cases there was no actually failure. As alarming but as harmless as a failed OP gauge on a Lycoming. There was a genuine failure a few months ago - perhaps that's the one you're referring to
I'm quite looking forward to hearing how the Austro engines work in practice. As Generation 2 engines (albeit from a start-up engine manufacturer) they should have significant improvements.