DA62 makes emergency landing on Dallas street

If fueled with 100LL I wouldn’t figure they’d have made it much past the opposite end of the departure runway.
Maybe the mains were already full and they just needed to top up the aux tanks.. burn some off of the mains and then switch to drink from the auxiliary part way through the flight

Either way this one is a head scratcher for sure
 
Yes. But I don't know if the props will feather with engine in run position, but no fuel. You may have to hit the stop button for that.
The 42 NG will feather automatically when the rpm drops below 800(?) if I remember correctly. It’s not a separate function or control.
 
I wonder if that was the factory wiring or if it had work done on the system(s) after delivery?
 
I wonder if that was the factory wiring or if it had work done on the system(s) after delivery?
Sounds like the ECU batteries are an annually-serviced item, so unless it’s less than a year old, it wouldn’t be a factory error.
 
I wonder if that was the factory wiring or if it had work done on the system(s) after delivery?

Sounds like the ECU batteries are an annually-serviced item, so unless it’s less than a year old, it wouldn’t be a factory error.

The aircraft is a 2018 model, so very likely a servicing issue.
 
The aircraft is a 2018 model, so very likely a servicing issue.
And you are at the mercy of the service facility on this one. The emergency controller unit switch backup battery is safety wired off and the preflight check is to make sure it’s off and wired so. At least in DA-42NG and DA-40NG.
 
Sounds like the ECU batteries are an annually-serviced item, so unless it’s less than a year old, it wouldn’t be a factory error.

They’re must be replaced annually. It’s an airworthiness limitation.
 
In a scenario like this, would the maintenance facility be liable? I suppose the aircraft owner’s insurance pays, then maybe goes after the shop if they feel it’s worth the fight?
 
They’re must be replaced annually. It’s an airworthiness limitation.
So these engines have an EEC dual battery system vs a FADEC permanent magnet alternator (PMA) system? I thought Austro used FADEC or am I thinking of something different?
 
So these engines have an EEC dual battery system vs a FADEC permanent magnet alternator (PMA) system? I thought Austro used FADEC or am I thinking of something different?

Disclaimer: I'm speaking from experience with a DA40NG only. I assume the DA62 engine installation is similar but I don't know for a fact it is...

The Austro has a fairly conventional battery and charging system. One alternator and one battery. There are two engine ECUs, each of which has a backup battery which is intended to keep the charging system working or power the ECU for a period of time if the main battery goes offline for some reason. These backup batteries are an airworthiness item and must be replaced annually.

Edit: I just checked the DA62 manual. The system looks the same.
 
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If the pilot had checked the work and found the improper installation, would he have been obligated to give the incompetent another chance to crash his plane or could he have just done it right himself?
Depends. Maybe the pilot was the one who changed out or worked on the batteries?
 
If the pilot had checked the work and found the improper installation, would he have been obligated to give the incompetent another chance to crash his plane or could he have just done it right himself?
From what I’ve heard, this isn’t a very preflightable part of the airplane, so he’d probably have to be looking directly over the mechanic’s shoulder to find it.

But given that the pilot appears to have flown the airplane in a condition prohibited by the AFM, it looks like he chose to crash it himself.
 
From what I’ve heard, this isn’t a very preflightable part of the airplane, so he’d probably have to be looking directly over the mechanic’s shoulder to find it.

If I’m understanding what happened correctly, a pilot with an above average knowledge and understanding of the aircraft’s systems could have figured out that the batteries weren’t hooked up without having any of the aircraft disassembled. But, that would require someone inquisitive (or stupid) enough to do things outside of what the flight manual or checklists prescribe.
 
If I’m understanding what happened correctly, a pilot with an above average knowledge and understanding of the aircraft’s systems could have figured out that the batteries weren’t hooked up without having any of the aircraft disassembled. But, that would require someone inquisitive (or stupid) enough to do things outside of what the flight manual or checklists prescribe.
I don’t know enough about it…I’ve heard it’s not part of the normal system checks, but I don’t know if it CAN be checked.
 
Is that something he would have been allowed to do himself?
While I dont know the particulars on a DA62, battery replacement/servicing does fall under Part 43 prevent mx. However given the avionics and the engines shutdown about the same time, fuses blown on the EEC batteries and the main battery at 70% capacity it appears there is more than one issue at hand. As a reference, 85% capacity is the bottom limit on serviceability for most batteries.
 
I don’t know enough about it…I’ve heard it’s not part of the normal system checks, but I don’t know if it CAN be checked.

It probably wouldn't be a "normal" check. Basically, the aircraft is set up so it would act like a normal piston powered aircraft would if you had to shut off the master switch in flight for some reason, and the check could be that simple.
 
Completely random question - do diesel aviation engines have the same risk of water in the fuel that gas engines do? I'd think yes, but I don't know what systems jet fuel delivery systems have to prevent water problems, or if jet engines are as intolerant of water as IC engines are.
Diesel engines are VERY intolerant of water in the fuel. Among other things it can flash to steam and blow the tips off the injector nozzles, besides for wrecking the high pressure pump and just not being flammable.
Not that this was the case here though.
 
It probably wouldn't be a "normal" check. Basically, the aircraft is set up so it would act like a normal piston powered aircraft would if you had to shut off the master switch in flight for some reason, and the check could be that simple.
Not on the 42 and I reasonably sure on the 62.

Speaking of 42 here:
there is a switch at the top of the panel that has a safety cover which is wired shut. Making sure the cover is closed and the wire keeping it shut is a preflight item. Should the main electrical system fail (and the standby buss) the ECUs can be powered by breaking or removing the wire, opening the cover and turning on the switch. In the DA42 that’s about 1/2 hour of power for the ECUs. But to test you’d have to kill the main power, remove the wire and turn on the backup. Which renders the AC unairworthy until the back system is serviced.
 
Hmmm, it seems a gauge on this system to show back up power is available for the ECU would be a good addition.
 
Hmmm, it seems a gauge on this system to show back up power is available for the ECU would be a good addition.
Perhaps. I mean it’s the third backup and is annually serviced. If this is due to a servicing error change the procedures. Retrofit to the whole fleet? Maybe not.
 
Perhaps. I mean it’s the third backup and is annually serviced. If this is due to a servicing error change the procedures. Retrofit to the whole fleet? Maybe not.

Retrofit? No, but new models? Yup, or at least test button.
 
Not on the 42 and I reasonably sure on the 62.

Speaking of 42 here:
there is a switch at the top of the panel that has a safety cover which is wired shut. Making sure the cover is closed and the wire keeping it shut is a preflight item. Should the main electrical system fail (and the standby buss) the ECUs can be powered by breaking or removing the wire, opening the cover and turning on the switch. In the DA42 that’s about 1/2 hour of power for the ECUs. But to test you’d have to kill the main power, remove the wire and turn on the backup. Which renders the AC unairworthy until the back system is serviced.

The emergency switch you’re referring to has no connection to the engine ECUs. That is a separate backup battery from the ECU batteries.

Perhaps. I mean it’s the third backup and is annually serviced. If this is due to a servicing error change the procedures. Retrofit to the whole fleet? Maybe not.

The backup battery you’re referring to must be changed biennially.
 
The emergency switch you’re referring to has no connection to the engine ECUs. That is a separate backup battery from the ECU batteries.



The backup battery you’re referring to must be changed biennially.
Yes, after I posted that I thought more about it. That's the backup power for the essential buss. 30 minutes of AI and minimum radios to get on the ground if both alternators and the battery (ies?) are shot. ECUs have their own backup. I would have thought they'd test as part of the automatic engine run-up. It does switch back and forth between ECUs during that (and as part of the pre-flight checks). It was April when I last flew the DA-42NG.
 
Yes, after I posted that I thought more about it. That's the backup power for the essential buss. 30 minutes of AI and minimum radios to get on the ground if both alternators and the battery (ies?) are shot. ECUs have their own backup. I would have thought they'd test as part of the automatic engine run-up. It does switch back and forth between ECUs during that (and as part of the pre-flight checks). It was April when I last flew the DA-42NG.

Powering up the ecus from the back up would likely run it down. It does sound like some type of hiccup or oversight that they might be improperly installed and the system doesn't catch it.
 
Powering up the ecus from the back up would likely run it down. It does sound like some type of hiccup or oversight that they might be improperly installed and the system doesn't catch it.

Im guessing that it was simply a case of the batteries being unhooked for one reason or another. Or there were other problems with the charging system and the batteries simply got depleted.


One thing that crossed my mind was wondering if the standby batteries were intentionally left disconnected so the ECU switches could be left on so it acts more like a car where the engine can be started and stopped from the key switch.
 
Im guessing that it was simply a case of the batteries being unhooked for one reason or another.
Or connected in reverse polarity? The report mentions blown inline fuses on the backup power side. How do the back up batteries come on line?
 
One other thing I don't remember about the DA-42 is whether each ECU has its own backup battery or there is one shared for the two ECUs for an engine? There are two ECUs per engine. Normal operations takes turns each time you start up with the ECU switch in "both"-this time ECU A, next time ECU B, etc. Checking both ECU's individually is part of the preflight-but that's on ship's power.
 
Or connected in reverse polarity? The report mentions blown inline fuses on the backup power side. How do the back up batteries come on line?

When the ECU power comes on the backup batteries are brought online. If you have the ECU power switch turned on before the master switch, the ECU will power up. But if you turn the master off, the ECUs will remain powered by the backup batteries until the power is depleted or the ECU switch is turned off.

I wonder if something else was inadvertently disconnected or shorted which caused a high current draw from the backup batteries that in turn caused the fuses to blow. Hard to say at this point.
 
When the ECU power comes on the backup batteries are brought online. If you have the ECU power switch turned on before the master switch, the ECU will power up. But if you turn the master off, the ECUs will remain powered by the backup batteries until the power is depleted or the ECU switch is turned off.

I wonder if something else was inadvertently disconnected or shorted which caused a high current draw from the backup batteries that in turn caused the fuses to blow. Hard to say at this point.
Is it possible to do something like leave the alternator side off on a split master so the ECUs were running off the batteries until they ran down?
 
Is it possible to do something like leave the alternator side off on a split master so the ECUs were running off the batteries until they ran down?

It appears that the DA62 has separate alternator switches (not a split switch) that potentially could be left off. This is an area that is different from the aircraft I am familiar with, so I can’t speak from personal flight or maintenance experience.
 
When the ECU power comes on the backup batteries are brought online.
Do you have a schematic for this? What's interesting is the avionics and engines failed at the same time. Why the avionics? Given the main battery was junk, maybe it tripped (the pop noise?) the charge system causing loss of main power that dropped the avionics and FADECs? And when the ECU back up batteries "came on line" they smoked the fuses due to "improper" wiring or a failed diode? Will be curious to know if he had to jump start the plane to leave.
 
Do you have a schematic for this? What's interesting is the avionics and engines failed at the same time. Why the avionics? Given the main battery was junk, maybe it tripped (the pop noise?) the charge system causing loss of main power that dropped the avionics and FADECs? And when the ECU back up batteries "came on line" they smoked the fuses due to "improper" wiring or a failed diode? Will be curious to know if he had to jump start the plane to leave.

Diamond has the flight and maintenance manuals readily available for these aircraft. Here's the DA62 flight manual, which includes a basic schematic.

http://support.diamond-air.at/filea...ht_Manual/Basic_Manual/70125e-r4-complete.pdf

The backup ECU batteries are supposed to keep the ECU bus powered if there is an interruption in the main battery circuit. My guess is that everything went black at the same time because everything was running off the main battery and the alternators weren't charging, then the battery voltage dropped low enough that the electronics could no longer function. You'd think there would have been low voltage alarms going off in the G1000...
 
You'd think there would have been low voltage alarms going off in the G1000...
Per the AFM there would have been a number of lights lit up and low readings if flying with both ALT out. And if he was, he owns this. What's interesting is those ECU back up batteries also power the alternator field windings in the event of a main battery failure and not just the ECUs and respective fuel pump. My SWAG is the main battery went belly up in flight and tripped the main CB which caused the #1 & #2 alternators to scram and instead of the #1 and #2 ECU batteries coming to the rescue smoked due to "improper wiring" on both systems. You would think at least one engine would have stayed running with 5 separate yet interconnected on board power sources. Ahhh, technology only as strong as the weakest link... or wire.:eek:
 
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