DA42 double engine failure
I am glad this has stayed a sensible discussion from which we can all learn.
The engines will continue to run with the Master Switch off.
This means that you could experience some major electrical problems (smoke in the cockpit?), turn off the Master and the engines keep humming.
For some reason it has the idiosyncrasy that led to the above discussed accident.
Some weird combination of circumstances led to this.
That door will need to be closed, either by Thielert or by Diamond.
No discussion there really.
But it needs to be made clear that not every little or large electrical problem will lead to a double engine shut down.
Just in this case somebody managed (unfortunately) to get all the ducks lined up.
That is why you need to refer to it when something occurs that is not covered by the abbreviated checklist. That is why the POH needs to be in the cockpit area within reach.
Diamond uses the standard three prong plug.
On the DA-42 the receptacle is right in front of the nose gear well, if you follow the POH you can even disconnect it from the non running side.
Agree with you here. Unfortunately this is when, as a pilot, you need to raise a warning flag; step back and review the situation. That is the hard part, human factors. In a rush, in a hurry, under stress, peer pressure, they can all lead to cutting corners and taking risks that you normally would not.
In my humble opinion it takes a better pilot to cancel a flight then to go on one.
This is where I feel the POH should be clearer and more precise.
The glow plug ( remember, it's a diesel) takes app. 35 amps for 20 sec or so.
The starter motor takes another 30 amps, the battery needs to be sufficiently charged before you attempt to start the second engine. It is probably worth mentioning in the POH that you may need to run the first engine for 5-10 min to charge the battery.
Agree...partially. I honestly do not have enough info on the accident. It is unknown how long they took to complete the checks before T/O. I suspect they did not take enough time on the ground to verify the battery was sufficiently charged and the bus voltage sufficiently high (read normal).
How long does it take to charge a 10Amp/hr battery with two 60 amp alternators? Not very long.
The DA-42 does not have a run-up in the classic sense,it has an ECU test which talkes all but 10 seconds.
I don't know for how long they taxied, but it could not have been long.
Me and my colleagues have had to GPU start a 42 three times now, in every case the master switch was left on during the preflight and the preflight briefing (inside the building). Normal procedures were followed and no problems there. 6-10 min before take-off and gear retraction.
In the case of the above accident the battery drained completely overnight, they very well may simply not have spend enough time charging the battery, causing the voltage drop with gear retraction.
In any case, I am sure Diamond will send follow up communications as to preventing this from happening again as they are working on a fix to prevent it all together.
and the checklist - and for that he paid - fortunately not with his life. It still begs the question as to whether the fact that this happened does not expose a deeper and far more alarming design failure by 'whoever', and a failure that needs an urgent fix.
This means that you could experience some major electrical problems (smoke in the cockpit?), turn off the Master and the engines keep humming.
For some reason it has the idiosyncrasy that led to the above discussed accident.
Some weird combination of circumstances led to this.
That door will need to be closed, either by Thielert or by Diamond.
No discussion there really.
But it needs to be made clear that not every little or large electrical problem will lead to a double engine shut down.
Just in this case somebody managed (unfortunately) to get all the ducks lined up.
Instead, you use an abbreviated checklist because the actual POH is too big to have on your lap at all times.
Find the GPU receptacle, possibly discovering that the standard plugs do not fit.
The stress of having somebody walking very close to the fuselage with the engines running.
you can argue that one of the things a pilot needs to do is manage stress, and that all this should not impact your performance, but you have to admit that this may just be a factor in not starting to read the POH, looking for the appropriate checklist.
In my humble opinion it takes a better pilot to cancel a flight then to go on one.
So if I were to find out that after starting the first engine and disconnecting the GPU, the second engine wouldn't start? I would hook up the GPU again and start the second engine.
The glow plug ( remember, it's a diesel) takes app. 35 amps for 20 sec or so.
The starter motor takes another 30 amps, the battery needs to be sufficiently charged before you attempt to start the second engine. It is probably worth mentioning in the POH that you may need to run the first engine for 5-10 min to charge the battery.
The aircraft should be designed so that this does not lead to a potentially deadly incident, which EFATO clearly is. So if it is possible to get into a situation where you have both engines running but a depleted main battery (either though an improperly executed GPU procedure or in the situation where the battery just had enough juice to start two engines but then gave up the ghost) then the aircraft should be designed so that at the very least, when you raise the gear, the engines keep on running.
How long does it take to charge a 10Amp/hr battery with two 60 amp alternators? Not very long.
The DA-42 does not have a run-up in the classic sense,it has an ECU test which talkes all but 10 seconds.
I don't know for how long they taxied, but it could not have been long.
Me and my colleagues have had to GPU start a 42 three times now, in every case the master switch was left on during the preflight and the preflight briefing (inside the building). Normal procedures were followed and no problems there. 6-10 min before take-off and gear retraction.
In the case of the above accident the battery drained completely overnight, they very well may simply not have spend enough time charging the battery, causing the voltage drop with gear retraction.
In any case, I am sure Diamond will send follow up communications as to preventing this from happening again as they are working on a fix to prevent it all together.
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In all the discussion it should not be forgotten the 42 is a very new design and so is much of the technology.
I am not making any excuses for what may arguably be faults in the design, but I wonder whether the 42 is any more or less prone to the odd design fault compared with aircraft of yester year or whether the testing is less rigorous than in the past.
I have getting on for 50 hours now on this type and am in no doubt all of those hours have proved invaluably in understanding the systems, and in particular the emergency procedures. A number of other "issues" have arisen during this period and I know that Diamond have in hand a few modifications.
However, as others have said, the POH on this particular issue is in my view quite clear. If the pilots had followed the POH they would not have allowed this combination of circumstances to cause the failure. I cant imagine in any twin that you would not consult the POH before a ground start after a flat battery.
I think it does however reinforce the importance of having the POH with you if you intend to fly more complex types. The G1000 instrumentation provides a far greater range of fault finding information than conventional instrumentation, and by its very nature has greater propensity for unfamiliar faults to arise. Personally I wouldn’t go anywhere in a 42 without the POH, and also the supplementary manuals produced by Garmin and Diamond. The fact of the matter is they are all available as a PDF if you want to keep the original safe and are really not that bulky.
Without the POH a GUI annunciated fan fail will grab your attention mid channel in IMC and you may have no idea whether one or other or both of the glass screens is about to overheat or what actions to take. In fact your concern would be completely misplaced about either screen over heating, but you might well be excused for jumping to the wrong conclusion.
However, and all that said, the POH could in a number of cases be more descriptive of the fault background and more specific as to actions to be taken and why. For example a GUI fan fail may either mean the blower to the avionics bay has failed or the fault reporting circuit has failed. The POH gives little information of if and in what circumstances the avionics are likely to overheat and if they do, what the consequences are, other than a comforting continue the flight but have the system inspected when next on the ground.
Another good example is the consequence of an engine failure. The POH is silent on whether or not the autopilot can be used single engine. You would have thought anyone flying a 42 would want to know before their first flight.
I am not making any excuses for what may arguably be faults in the design, but I wonder whether the 42 is any more or less prone to the odd design fault compared with aircraft of yester year or whether the testing is less rigorous than in the past.
I have getting on for 50 hours now on this type and am in no doubt all of those hours have proved invaluably in understanding the systems, and in particular the emergency procedures. A number of other "issues" have arisen during this period and I know that Diamond have in hand a few modifications.
However, as others have said, the POH on this particular issue is in my view quite clear. If the pilots had followed the POH they would not have allowed this combination of circumstances to cause the failure. I cant imagine in any twin that you would not consult the POH before a ground start after a flat battery.
I think it does however reinforce the importance of having the POH with you if you intend to fly more complex types. The G1000 instrumentation provides a far greater range of fault finding information than conventional instrumentation, and by its very nature has greater propensity for unfamiliar faults to arise. Personally I wouldn’t go anywhere in a 42 without the POH, and also the supplementary manuals produced by Garmin and Diamond. The fact of the matter is they are all available as a PDF if you want to keep the original safe and are really not that bulky.
Without the POH a GUI annunciated fan fail will grab your attention mid channel in IMC and you may have no idea whether one or other or both of the glass screens is about to overheat or what actions to take. In fact your concern would be completely misplaced about either screen over heating, but you might well be excused for jumping to the wrong conclusion.
However, and all that said, the POH could in a number of cases be more descriptive of the fault background and more specific as to actions to be taken and why. For example a GUI fan fail may either mean the blower to the avionics bay has failed or the fault reporting circuit has failed. The POH gives little information of if and in what circumstances the avionics are likely to overheat and if they do, what the consequences are, other than a comforting continue the flight but have the system inspected when next on the ground.
Another good example is the consequence of an engine failure. The POH is silent on whether or not the autopilot can be used single engine. You would have thought anyone flying a 42 would want to know before their first flight.
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To delay mowing the lawn, I've just been studying the wiring diagrams of the DA40 and 42. This thread made me wonder what would happen if the short circuit that was reported in a DA40, in the current occurrences list (200610457), happened in a DA42. The battery relay short circuited, so the electric master had to be switched off, but luckily, the DA40 was on the ground. If this had happened while airborne, after the smoke had cleared, the ECU backup battery should have kept the engine running for up to 20 minutes, and the backup AI should have been OK with its own emergency batteries, but the radios, navaids and GPS would have been unavailable. Not a good time to be mid-channel, but otherwise a situation you could cope with.
The DA42's wiring is more complicated, but it looks as though the situation would be the same, except that each ECU would be powered by the alternator on its engine. Normal operation of the landing gear would not be possible, as there would be no power to the main bus, so it would have to be dropped manually, and there would be no risk of the engines cutting out.
Protecting the ECUs from transients only seems to be necessary when the battery is discharged and the electric master is switched on. It seems to me that the simplest solution would be to put a voltmeter across the battery, and display the output from that on the MFD. Displaying a low battery voltage alert should make most of us reach for the POH.
Can't put off getting the lawn mower out any longer ...
The DA42's wiring is more complicated, but it looks as though the situation would be the same, except that each ECU would be powered by the alternator on its engine. Normal operation of the landing gear would not be possible, as there would be no power to the main bus, so it would have to be dropped manually, and there would be no risk of the engines cutting out.
Protecting the ECUs from transients only seems to be necessary when the battery is discharged and the electric master is switched on. It seems to me that the simplest solution would be to put a voltmeter across the battery, and display the output from that on the MFD. Displaying a low battery voltage alert should make most of us reach for the POH.
Can't put off getting the lawn mower out any longer ...
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I have no knowledge of the electrical system or the type of battery used, but you cannot put 60 amps into a conventional battery without a very big bang! If the battery is fully flat and it is being charged conventionally you would need hours not minutes for it to be voltage stable under load.
Rod1
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soay, I agree with you in principle. If you would have some sort of "low battery" warning, most of us would not take off until it disappeared, or grab the abnormal/emergency checklist when in the air. However... I think this is very hard to implement in practice. After all, a voltmeter across the battery would show the *alternator* voltage (about 14 or 28 volts) once the alternators are running and connected to the battery, not the disconnected-battery voltage.
I'm not an electronics engineer but I believe you need some very sophisticated equipment to determine the state of a battery that's being charged. (OTOH - my laptop battery can show the % charged even when charging, so it is doable.)
B2N2 - I think you just gave the best advice which works in any case, regardless of the type of aircraft. After a GPU-assisted start, make sure you run the engines for at least five, maybe even ten minutes to get a minimal charge in the batteries before taking off. (On the other hand, don't certain types of alternators require a minimum RPM before supplying the 14/28 volts required to charge the battery?)
I'm not an electronics engineer but I believe you need some very sophisticated equipment to determine the state of a battery that's being charged. (OTOH - my laptop battery can show the % charged even when charging, so it is doable.)
B2N2 - I think you just gave the best advice which works in any case, regardless of the type of aircraft. After a GPU-assisted start, make sure you run the engines for at least five, maybe even ten minutes to get a minimal charge in the batteries before taking off. (On the other hand, don't certain types of alternators require a minimum RPM before supplying the 14/28 volts required to charge the battery?)
If the battery is fully flat and it is being charged conventionally you would need hours not minutes for it to be voltage stable under load.
Same solution as with "normal" airplanes.
DA-42 idle is set at 900 rpm and the alternators are charging at this setting.
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Am I the only one who's puzzled by the POH?
You have flat batteries
You start one engine using ground power
You disconnect the ground power
You now have flat batteries being charged by one alternator
You get enough charge into the batteries to crank the other engine, that depletes the charge, you have flat batteries again.
You take off.
Who's to say that the charge in the batteries is now sufficient to maintain voltage under load?
You have flat batteries
You start one engine using ground power
You disconnect the ground power
You now have flat batteries being charged by one alternator
You get enough charge into the batteries to crank the other engine, that depletes the charge, you have flat batteries again.
You take off.
Who's to say that the charge in the batteries is now sufficient to maintain voltage under load?
After starting the first engine, the GPU is disconnected so that the pilot can be sure that the aeroplane alternator is capable of powering the electrical system. The use of the battery to start the second engine proves that the battery is recharging properly - and therefore you can be confident that the battery is serviceable. Having decent alternators means that the battery charges quickly - unlike those on some conventional aeroplanes where there is insufficient alternator output at idle to prevent battery depletion.
I don't buy the arguments of moggiee et al. For years aircraft crashed because non-return valves were manufactured so that they could be inserted either way round. Writing documentation that said they had to be inserted the right way round didn't fix it. Making it mechanically impossible by having differing threads on each end did.
The problem with even an almost-idiot-proof-SOP is that there is an SOP-proof idiot out there somewhere. Despite SOPs, landing checklists and green lights (lack of) there are still people who get it wrong and land wheels up.
My reference to the Kegworth B737-400 crash, for example, showed that despite FOUR indications of an engine problem on the LEFT engine (fluctuating N1, high EGT, low & fluctuating fuel flow and finally a full-scale vibration indication) the crew still managed to shut down the RIGHT hand engine by mistake because they did not follow their SOP.
The DA42 does need a re-design to prevent this happening again, and I'm confident that it will come. In the meantime, if crews follow the SOP and POH then this accident will not recur. However, as sure as the sun coming up each day, someone, somewhere today will be breaking an aeroplane because he did not follow the correct drills - either in normal or non-normal circumstances.
As crew, you are there as the last line of defence against the failings of the designers. No train, plane or automobile is 100% perfect, and most of us know that. The dangerous people are those who believe that a) the aeroplanes ARE perfect and that they will be safe no matter how little they know or b) that they know better than the designers/manufacturers who have flight tested and certified the aeroplane.
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It's a sod to get out, though. We did that a while back when we had a flat battery, ensuring that it was charged before re-installation.
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“Having decent alternators means that the battery charges quickly - unlike those on some conventional aeroplanes where there is insufficient alternator output at idle to prevent battery depletion.”
When I designed my electrical system I had to read a lot of text books. I will look it up tonight, but the rate a lead acid battery will charge, using standard charging circuitry, is very slow. I think, from flat, you would need hours, not minutes. An interesting point to note here is that when a power load is drawing a high current from the battery, the voltage will drop. This may mean that the battery needs to be somewhere near 50% charged to avoid a low voltage situation.
You have no reliable way to know the charge state of the battery you are about to rely on to avoid a nasty surprise.
Rod1
When I designed my electrical system I had to read a lot of text books. I will look it up tonight, but the rate a lead acid battery will charge, using standard charging circuitry, is very slow. I think, from flat, you would need hours, not minutes. An interesting point to note here is that when a power load is drawing a high current from the battery, the voltage will drop. This may mean that the battery needs to be somewhere near 50% charged to avoid a low voltage situation.
You have no reliable way to know the charge state of the battery you are about to rely on to avoid a nasty surprise.
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I think there may be a point that is being overlooked and this applies to all aircraft.
If a battery is too discharged to make a start by a short term drain like leaving the master on while briefing, it will usually still have adequate capacity to power anciallaries once the engine is started. It also will often make a re-start immediately, but this is because the battery still has substantial capacity left and the engine is hot, not because it has re-charged in a few minutes.
If a battery has become completely discharged, by leaving the master on all night for instance, then it is a different issue. The battery (with a resistive load) will have no capacity left at all and may also be damaged. No amount of ground running in this situation will make the battery 'safe' from the point of view of capacity after an alternator failure or any load exceeding the alternator output because the charge rate is so low that hours of flying would be required first.
In my view a battery that is completely flat also presents a hazard to the alternator because the current limiting regulator designer may not have envisaged the battery being a short circuit with an unknown restore time. Outcomes could include the one described in this thread, total electrical failure and in flight fire in almost any aircraft.
A lead acid battery will often be designed for a 12-hour charge and while a shorter time (say 1-2 hours) will prove that the battery is still serviceable, it is cavalier to just jump start and hope for the best in my view. I'd think twice about doing that in a Land Rover, let alone a glass cockpit IFR twin!
If a battery is too discharged to make a start by a short term drain like leaving the master on while briefing, it will usually still have adequate capacity to power anciallaries once the engine is started. It also will often make a re-start immediately, but this is because the battery still has substantial capacity left and the engine is hot, not because it has re-charged in a few minutes.
If a battery has become completely discharged, by leaving the master on all night for instance, then it is a different issue. The battery (with a resistive load) will have no capacity left at all and may also be damaged. No amount of ground running in this situation will make the battery 'safe' from the point of view of capacity after an alternator failure or any load exceeding the alternator output because the charge rate is so low that hours of flying would be required first.
In my view a battery that is completely flat also presents a hazard to the alternator because the current limiting regulator designer may not have envisaged the battery being a short circuit with an unknown restore time. Outcomes could include the one described in this thread, total electrical failure and in flight fire in almost any aircraft.
A lead acid battery will often be designed for a 12-hour charge and while a shorter time (say 1-2 hours) will prove that the battery is still serviceable, it is cavalier to just jump start and hope for the best in my view. I'd think twice about doing that in a Land Rover, let alone a glass cockpit IFR twin!
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If you want to know everything about aircraft electrical systems have a look at;
http://www.aeroelectric.com/
Lots of battery stuff. Advice is charge a flat battery for 4 – 6 hours before relying on it to be voltage stable under load. This does not change no mater how good the alternators! You will also find a very good article on the difficulties of testing the “capacity” of a partly discharged battery, including some practical ways of doing this (in VMC).
Rod1
http://www.aeroelectric.com/
Lots of battery stuff. Advice is charge a flat battery for 4 – 6 hours before relying on it to be voltage stable under load. This does not change no mater how good the alternators! You will also find a very good article on the difficulties of testing the “capacity” of a partly discharged battery, including some practical ways of doing this (in VMC).
Rod1
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Single Engined Auto Pilot
Fuji,
The POH Supplement "A13 - Autopilot" clearly states that the Autopilot can not be used for single engined operations.
It is also written on the very poorly placed placard on, by the door catch on the P1 side.
TY
The POH Supplement "A13 - Autopilot" clearly states that the Autopilot can not be used for single engined operations.
It is also written on the very poorly placed placard on, by the door catch on the P1 side.
TY
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3Y
Thanks for that - and I dont know how I missed that supp! At least all now read and digested.
I am told the KAP140 operates fine on one engine - but clearly outside the POH so I will be avoiding that particular route should the need ever arise
.
Thanks for that - and I dont know how I missed that supp! At least all now read and digested.
I am told the KAP140 operates fine on one engine - but clearly outside the POH so I will be avoiding that particular route should the need ever arise
.
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Originally Posted by B2N2
That is why you need to refer to it when something occurs that is not covered by the abbreviated checklist. That is why the POH needs to be in the cockpit area within reach.
Originally Posted by Rod1
I have no knowledge of the electrical system or the type of battery used, but you cannot put 60 amps into a conventional battery without a very big bang!
You can add procedures as much as you want to the PoH for liability reasons, but it will never prevent accidents. On a conventional aircraft a PoH for morons may say reduce power with the throttle, but the the mixture will still be big, red and knobbly because it's a cheap and effective design solution preventing a proven mode of accidental user induced engine shutdown...
This failure mode unaddressed will dent confidence in any electronically controlled a/c engine, which is a shame as diesel and FADEC are quite obviously the future and 30yrs overdue....
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on avweb:
Diamond DA42 Engine Fix: Engine AD in the Works?
Diamond Aircraft said on Friday that it’s continuing its investigation into the dual engine failure of a diesel-powered DA42 Twin Star last month in Germany, and the fix might be a backup battery for the engine’s electronic control units (ECUs). In meantime, AVweb has learned that an Airworthiness Directive for the airplane’s two Thielert 1.7 Centurion engines is pending. Diamond North American president Peter Maurer told AVweb on Friday that Thielert -- the engine supplier -- and Diamond aren’t working at cross purposes, since the problem obviously needs to be corrected. Maurer said that both of the Twin Star’s engines quit immediately after the pilot retracted the landing gear. Activation of the gear retraction system caved the electrical system voltage and knocked both ECUs offline. When the engines quit, the props immediately feathered and the airplane’s dual alternators, which are supposed to provide failsafe power to the ECUs, also died. The airplane landed with the gear partially retracted and was significantly damaged. Fortunately, the crew survived.
According to Diamond, the pilot found the aircraft with a dead battery, then took off immediately after starting it with ground power, without completely charging the battery. Although the airplane has dual alternators and dual buses, it’s unclear how independent the two buses actually are, since they’re connected through a battery isolation relay. In any case, neither alternator was delivering power because the offline ECUs stopped both engines. The ECUs are designed to reset after a failure, but will do so only if provided with sufficient operating voltage. One fix -- although it hasn’t been decided yet -- is to provide each ECU with its own independent backup battery or to isolate the dual buses more effectively, as some all-electric aircraft do. Diamond’s single-engine diesel, the DA40tdi, has a backup battery and Diamond has also discrete batteries for improved starting and for instruments in its two-seat DA20 C1 model. Another approach, says Maurer, is to use capacitors to bridge momentary voltage transients. Diamond and Thielert have yet to decide whether the proposed fix will be an engine or an airframe mod. Either way, says Maurer, airplanes will be retrofitted in the field, once the fix is developed
Diamond DA42 Engine Fix: Engine AD in the Works?
Diamond Aircraft said on Friday that it’s continuing its investigation into the dual engine failure of a diesel-powered DA42 Twin Star last month in Germany, and the fix might be a backup battery for the engine’s electronic control units (ECUs). In meantime, AVweb has learned that an Airworthiness Directive for the airplane’s two Thielert 1.7 Centurion engines is pending. Diamond North American president Peter Maurer told AVweb on Friday that Thielert -- the engine supplier -- and Diamond aren’t working at cross purposes, since the problem obviously needs to be corrected. Maurer said that both of the Twin Star’s engines quit immediately after the pilot retracted the landing gear. Activation of the gear retraction system caved the electrical system voltage and knocked both ECUs offline. When the engines quit, the props immediately feathered and the airplane’s dual alternators, which are supposed to provide failsafe power to the ECUs, also died. The airplane landed with the gear partially retracted and was significantly damaged. Fortunately, the crew survived.
According to Diamond, the pilot found the aircraft with a dead battery, then took off immediately after starting it with ground power, without completely charging the battery. Although the airplane has dual alternators and dual buses, it’s unclear how independent the two buses actually are, since they’re connected through a battery isolation relay. In any case, neither alternator was delivering power because the offline ECUs stopped both engines. The ECUs are designed to reset after a failure, but will do so only if provided with sufficient operating voltage. One fix -- although it hasn’t been decided yet -- is to provide each ECU with its own independent backup battery or to isolate the dual buses more effectively, as some all-electric aircraft do. Diamond’s single-engine diesel, the DA40tdi, has a backup battery and Diamond has also discrete batteries for improved starting and for instruments in its two-seat DA20 C1 model. Another approach, says Maurer, is to use capacitors to bridge momentary voltage transients. Diamond and Thielert have yet to decide whether the proposed fix will be an engine or an airframe mod. Either way, says Maurer, airplanes will be retrofitted in the field, once the fix is developed
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A capacitor, IMHO, would only help to bring the time an ECU can sustain a power transient, from 1.7 to 50 ms. I don't know what the switching time for a relay is, but this sounds about right for that. But 50 ms would not be enough to sustain a too-low bus voltage due to gear retraction - unless the DA-42 has some of the fastest retracting gear in the industry.
Backup battery sounds like the way to go.
Backup battery sounds like the way to go.
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Isnt there also a problem with backup batteries.
The batteries fitted on the 40 are very small and I gather have been found in a state of very low charge. Their life would also seem to be poor. I guess there is a positive check however in that I think the red button on the ECU panel on the 40 switches the ECUs to run on the backup battery and so presumably proves it is functional. However I am not certain this exists on all versions of the 40 ? In any event if a backup battery was the solution presumably some form of proving the backup would be required on the 42 ?
The batteries fitted on the 40 are very small and I gather have been found in a state of very low charge. Their life would also seem to be poor. I guess there is a positive check however in that I think the red button on the ECU panel on the 40 switches the ECUs to run on the backup battery and so presumably proves it is functional. However I am not certain this exists on all versions of the 40 ? In any event if a backup battery was the solution presumably some form of proving the backup would be required on the 42 ?
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In response to ‘sternone’ report:
It is reassuring to hear that the three principles in the affair are working together towards a proper solution to this alarming failure. I have little doubt that between then a satisfactory fix will be arrived at.
Let us hope it ensures the engines keep running after a transitory voltage drop as well as after a total busbar collapse. Let us also hope they keep running for more than the time it takes to decide which God your going to put your money on!
As for who is to blame and who pays, let the lawyers get fat on that, God bless them!
I like to think this is probably an end to the matter in the real world. Lets hope so.
It is reassuring to hear that the three principles in the affair are working together towards a proper solution to this alarming failure. I have little doubt that between then a satisfactory fix will be arrived at.
Let us hope it ensures the engines keep running after a transitory voltage drop as well as after a total busbar collapse. Let us also hope they keep running for more than the time it takes to decide which God your going to put your money on!
As for who is to blame and who pays, let the lawyers get fat on that, God bless them!
I like to think this is probably an end to the matter in the real world. Lets hope so.