Another 787 electrical/smoke incident (on ground)
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BOAC:
See this link for info on test aircraft fire in 2010:
No split over similar-looking wingtips - FlightBlogger - Aviation News, Commentary and Analysis
It seems the fire was in the aft EE bay.
Also, the following quote describes the implications of electrical power failure on the 787.
See this link for info on test aircraft fire in 2010:
No split over similar-looking wingtips - FlightBlogger - Aviation News, Commentary and Analysis
It seems the fire was in the aft EE bay.
Also, the following quote describes the implications of electrical power failure on the 787.
US FAA to impose special conditions on Boeing 787 electric power
Boeing’s “more-electric” power architecture for the 787 will face special conditions to achieve airworthiness certification by the US FAA.
The extra certification requirements released today by the FAA require Boeing to prove that the 787 “is capable of recovering adequate primary electrical power generation for safe flight and landing” in the event of an in-flight power failure.
Boeing’s older airliners use pneumatic systems to power the hydraulics controlling flight control systems and landing gear, with comparatively small electric generators needed for onboard electronic systems.
But the 787 design omits the heavier pneumatic system in favor of electric power for the hydraulic actuators.
This change requires the aircraft’s two engines to drive four integrated drive generators providing 1.45MW of electricity, . The flight controls and landing gear depend on the electric generators as a primary power source.
The FAA recognizes the 787’s electric power as a potential safety concern that must be addressed by imposing special conditions beyond its normal airworthiness-proving requirements.
Boeing must show that the 787 is capable of safe flight with the engine and APUs inoperative. Alternate sources of power may include the battery, ram air turbine or a permanent magnet generating system.
The manufacturer also has to prove that the 787 has enough alternate sources of electrical power onboard to descend from the maximum operating altitude to the minimum altitude to attempt an engine and APU restart.Source: flightglobal.com's sister premium news site Air Transport Intelligence news
Boeing’s “more-electric” power architecture for the 787 will face special conditions to achieve airworthiness certification by the US FAA.
The extra certification requirements released today by the FAA require Boeing to prove that the 787 “is capable of recovering adequate primary electrical power generation for safe flight and landing” in the event of an in-flight power failure.
Boeing’s older airliners use pneumatic systems to power the hydraulics controlling flight control systems and landing gear, with comparatively small electric generators needed for onboard electronic systems.
But the 787 design omits the heavier pneumatic system in favor of electric power for the hydraulic actuators.
This change requires the aircraft’s two engines to drive four integrated drive generators providing 1.45MW of electricity, . The flight controls and landing gear depend on the electric generators as a primary power source.
The FAA recognizes the 787’s electric power as a potential safety concern that must be addressed by imposing special conditions beyond its normal airworthiness-proving requirements.
Boeing must show that the 787 is capable of safe flight with the engine and APUs inoperative. Alternate sources of power may include the battery, ram air turbine or a permanent magnet generating system.
The manufacturer also has to prove that the 787 has enough alternate sources of electrical power onboard to descend from the maximum operating altitude to the minimum altitude to attempt an engine and APU restart.Source: flightglobal.com's sister premium news site Air Transport Intelligence news
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BOAC
There was an extensive thread on this website with photography, I cannot locate it. The ZA002 fire was investigated by Boeing. The FAA certifications for Boeing 787 run to distribution, back up, and procedural, I haven't found any addressing fire, either suppression or mitigation (isolation).
I thought the final cause of fire was a "tool" left in the EE Bay. Seems to conflict with the link posted above by Avionista.
Wanna buy a 'Rolex'?
There was an extensive thread on this website with photography, I cannot locate it. The ZA002 fire was investigated by Boeing. The FAA certifications for Boeing 787 run to distribution, back up, and procedural, I haven't found any addressing fire, either suppression or mitigation (isolation).
I thought the final cause of fire was a "tool" left in the EE Bay. Seems to conflict with the link posted above by Avionista.
Wanna buy a 'Rolex'?
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The more I think about it, the seatback screens showed re-booting...doesnt that point to a something affecting the system electronics?
Not sure where the control system is for those, or why/what would cause a re-boot....
Not sure where the control system is for those, or why/what would cause a re-boot....
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Isn't power for IFE supplied by the APU battery? If the "problem" was the main Battery, power interruption at both batteries seems likely. From the outset, isn't the underlying problem distribution?
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IFE
Lyman,
The Cabin Equipment Center is in the forward EE bay, so I doubt it is powered by the APU battery.
From some training material I have:
7. If the miscellaneous equipment cooling system detects smoke, the COOLING
LOSS light shows and IFE is powered off.
- The airplane must be on ground and smoke cleared to turn the system back on
I think the answer's right there...
The Cabin Equipment Center is in the forward EE bay, so I doubt it is powered by the APU battery.
From some training material I have:
7. If the miscellaneous equipment cooling system detects smoke, the COOLING
LOSS light shows and IFE is powered off.
- The airplane must be on ground and smoke cleared to turn the system back on
I think the answer's right there...
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I gather the control surfaces on the 787 are operated by electro hydrostatic actuators (EHA), probably at least two per control surface for redundancy. For an EHA to work it needs an electrical supply plus a pulse code modulation (PCM) signal provided along the power supply wiring. Therefore, a reasonably high capacity electrical supply is vital and must always be available to power the EHAs to enable the cockpit controls to operate control surfaces, raise/lower the landing gear, etc.
Given the above, it is understandable that any doubts about the reliabilty and fail-safe functions of the 787's electrical system is going to make the FAA 'twitchy'. I suspect their review will be re- checking that there is no weakness in the design whereby a single point of failure could 'knock out' all the built-in redundancy.
Given the above, it is understandable that any doubts about the reliabilty and fail-safe functions of the 787's electrical system is going to make the FAA 'twitchy'. I suspect their review will be re- checking that there is no weakness in the design whereby a single point of failure could 'knock out' all the built-in redundancy.
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Lyman, sbo,
I think that in this case, the evac was a ground op, so the APU should be handling the power at this point, correct?
To me there seems to be a disconnect between the transfer....and an issue in power distribution system...
I am not clear that the 787 IFE is from the front bay...the 87 has several distribution centers, with an additional aft ee bay to save on wiring costs/weight...
I think that in this case, the evac was a ground op, so the APU should be handling the power at this point, correct?
The airplane must be on ground and smoke cleared to turn the system back on
I am not clear that the 787 IFE is from the front bay...the 87 has several distribution centers, with an additional aft ee bay to save on wiring costs/weight...
Last edited by FlightPathOBN; 17th Jan 2013 at 20:36.
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FPO,
From the training material I have, the CEC is in the front EE bay. I don't know if it is possible to specify another location, kinda doubt it. I recall the APU running in the evac video. Don't think it's possible an engine was running during the evac.
As I understand the systems, I think the APU battery is there only for the APU.
From the training material I have, the CEC is in the front EE bay. I don't know if it is possible to specify another location, kinda doubt it. I recall the APU running in the evac video. Don't think it's possible an engine was running during the evac.
As I understand the systems, I think the APU battery is there only for the APU.
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This change requires the aircraft’s two engines to drive four integrated drive generators providing 1.45MW of electricity, . The flight controls and landing gear depend on the electric generators as a primary power source.
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From Boeing 787 SDS 44-26-00:
"Systems Description Section 787
In-Flight Entertainment System I8000
Component Location
Description
1.
Forward Electronic Equipment (EE) Compartment
These in-flight entertainment (IFE) system components are in the cabin equipment center (CEC) in the forward EE bay:
●
Digital audio video controller (AVC-D)
●
Digital server unit (DSU) - D3
●
Configuration plug.
2.
Crown Area
These IFE system components are in the crown area above the passenger compartment ceiling:
●
Area distribution box (ADB) - gigabit
●
Digital tapping unit (TU)."
"Systems Description Section 787
In-Flight Entertainment System I8000
Component Location
Description
1.
Forward Electronic Equipment (EE) Compartment
These in-flight entertainment (IFE) system components are in the cabin equipment center (CEC) in the forward EE bay:
●
Digital audio video controller (AVC-D)
●
Digital server unit (DSU) - D3
●
Configuration plug.
2.
Crown Area
These IFE system components are in the crown area above the passenger compartment ceiling:
●
Area distribution box (ADB) - gigabit
●
Digital tapping unit (TU)."
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sb,
thanks for that...so the IFE is controlled from the forward EEC.
ground ops, ie, engines are not online, are a function of the APU or ground connect.
given the engines were off line, one would expect anything on the ac powered by the APU...
this points to the disco between shore power and ac...
thanks for that...so the IFE is controlled from the forward EEC.
ground ops, ie, engines are not online, are a function of the APU or ground connect.
given the engines were off line, one would expect anything on the ac powered by the APU...
this points to the disco between shore power and ac...
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FPO
You're welcome. One thing I haven't seen discussed in the threads about these troubles is that in my outfit's experience, there is a limitation on APU use. After running the APU, there is a minimum 25 minute cooldown period required because of shaft bowing in the APU. As I understand it, on a short turn like JAL has in BOS, they run the APU during the turn and don't even bother with ground power. Wonder if that will change?
I also heard from a buddy that in the UA incident when they diverted into MSY, they made the decision to divert when they couldn't get the APU started. In that case, they changed a generator only, as far as I know. Lots going on with this electrical beast, and I hope Boeing gets their sh1t together soon.
I also heard from a buddy that in the UA incident when they diverted into MSY, they made the decision to divert when they couldn't get the APU started. In that case, they changed a generator only, as far as I know. Lots going on with this electrical beast, and I hope Boeing gets their sh1t together soon.
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Battery from the forward EE bay..
also, today the Japan transport ministry investigator Hideyo Kosugi said the state of the battery indicated “voltage exceeding the design limit was applied” to it.
also, today the Japan transport ministry investigator Hideyo Kosugi said the state of the battery indicated “voltage exceeding the design limit was applied” to it.
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Is this a big a problem as the media is making it out to be?
I mean, how much will it cost for boeing to replace these batteries with
different types in all of the aircraft that have been sold to date?
I have seen on the news that the A380 had it's own teething problems when it came into service, in particular with cracks in the wings. As much of a problem as this may be, from a passenger perspective I'd have to applaud
boeing and the FAA and other regulatory bodies for making quick decisions
to get to the root of the problem without hesitation, for me from a public perspective these decision have upheld boeing integrity and not so much harmed it.
I mean, how much will it cost for boeing to replace these batteries with
different types in all of the aircraft that have been sold to date?
I have seen on the news that the A380 had it's own teething problems when it came into service, in particular with cracks in the wings. As much of a problem as this may be, from a passenger perspective I'd have to applaud
boeing and the FAA and other regulatory bodies for making quick decisions
to get to the root of the problem without hesitation, for me from a public perspective these decision have upheld boeing integrity and not so much harmed it.
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sb_sfo, FPO.
Right. The IFE equipment is in the forward Bay. I think it is Thales derived. Originally, 'CONNEXION', a Boeing company, was to have been the vendor for IFE, then PANASONIC, then THALES. CONNEXION went banko, and the THALES system became severely outdated due the delays...The gen cycle in the IFE field is eighteen MONTHS. The Company (Boeing) developed an offer to operators for a line installed system post delivery.
My concern involved the power source, though I did initially believe the equipment was AFT. With a Main Battery acting up, prior to APU start, as the source of the diversion, the distribution issue is moot until the switch over, if any.
Reviewing the FAA special consideration for LithIon install, I could not locate a rule that addressed charging, only retention issues in discharge... So the issue becomes one of charging, which of course gets very delicate when load is highly variable, as exists in failure condition.
FPO From your picture, I assume the two batteries are displayed after removal from the a/c, both aft and forward EE bay LiIon batteries. The tops are in front, the bulging one from the main battery, post "expansion". I am guessing the cases are Stainless?
Silver lining? If the two emergency landings involved tramp FOD and Gen failure, respectively, we look at a ground problem.
Right. The IFE equipment is in the forward Bay. I think it is Thales derived. Originally, 'CONNEXION', a Boeing company, was to have been the vendor for IFE, then PANASONIC, then THALES. CONNEXION went banko, and the THALES system became severely outdated due the delays...The gen cycle in the IFE field is eighteen MONTHS. The Company (Boeing) developed an offer to operators for a line installed system post delivery.
My concern involved the power source, though I did initially believe the equipment was AFT. With a Main Battery acting up, prior to APU start, as the source of the diversion, the distribution issue is moot until the switch over, if any.
Reviewing the FAA special consideration for LithIon install, I could not locate a rule that addressed charging, only retention issues in discharge... So the issue becomes one of charging, which of course gets very delicate when load is highly variable, as exists in failure condition.
FPO From your picture, I assume the two batteries are displayed after removal from the a/c, both aft and forward EE bay LiIon batteries. The tops are in front, the bulging one from the main battery, post "expansion". I am guessing the cases are Stainless?
Silver lining? If the two emergency landings involved tramp FOD and Gen failure, respectively, we look at a ground problem.
Last edited by Lyman; 18th Jan 2013 at 16:50.
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Very important and GOOD information
FlightPathOBN:
This points to a faster solution of this problem (and "threat") Av industry is facing.
Circuitry design or defective part(s)?
...Japan transport ministry investigator Hideyo Kosugi said the state of the battery indicated “voltage exceeding the design limit was applied” to it.
This points to a faster solution of this problem (and "threat") Av industry is facing.
Circuitry design or defective part(s)?
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Main Batteries
FlightPathOBN,
Thanks for the pic of the main battery (or batteries?). Not sure why we’re still on this APU bat thread, but I think we’re all finding it tough to decide which to post on.
My questions follow on from Lyman’s. Maybe you or someone else can answer...
(1) Have the 2 batteries been photographed in the forward electronics bay, or in a workshop? If in the electronics bay, the intact battery cannot be the APU bat. If in the workshop, the good battery is presumably for comparison.
(2) Presumably there are 2 main bats on the B787? If so, are they racked in close proximity?
PS
On a better monitor screen, I now see they are apparently on a wooden pallet!
Thanks for the pic of the main battery (or batteries?). Not sure why we’re still on this APU bat thread, but I think we’re all finding it tough to decide which to post on.
My questions follow on from Lyman’s. Maybe you or someone else can answer...
(1) Have the 2 batteries been photographed in the forward electronics bay, or in a workshop? If in the electronics bay, the intact battery cannot be the APU bat. If in the workshop, the good battery is presumably for comparison.
(2) Presumably there are 2 main bats on the B787? If so, are they racked in close proximity?
PS
On a better monitor screen, I now see they are apparently on a wooden pallet!
Last edited by Chris Scott; 18th Jan 2013 at 18:57. Reason: PS added