Qantas B744 Total electrical failure?
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747-400 - No APU or Ram Air Turbine Power? Just Battery?
On a 737-800 This is the procedure and events that occur in event of loss of Gen 1 and Gen 2 in flight on a 737-800:
1) STBY AC BUS and STBY DC BUS automatically switch to their back-up source upon loss of both
engine driven generators. The STANDBY PWR OFF amber light should not be illuminated!
If you see this light illuminated, the first check-list to be started [before the LOSS OF BOTH
ENGINE DRIVEN GENERATORS] is the STANDBY POWER OFF NNC (non normal check list)
2) Bus Transfer switch OFF
3) Electrical Hydraulic pump switches OFF
4) APU select Start & On Busses
5) Bus Transfer switch AUTO
3) Electrical Hydraulic pump switches ON (one at a time)
5) Max APU Start Alt FL250.
6) Declare MAY DAY, if loss of only 1 generator declare PAN PAN.
Looking at the news tonight you would think that no APU or RAM air was available for a 747-400 - is this the case?
1) STBY AC BUS and STBY DC BUS automatically switch to their back-up source upon loss of both
engine driven generators. The STANDBY PWR OFF amber light should not be illuminated!
If you see this light illuminated, the first check-list to be started [before the LOSS OF BOTH
ENGINE DRIVEN GENERATORS] is the STANDBY POWER OFF NNC (non normal check list)
2) Bus Transfer switch OFF
3) Electrical Hydraulic pump switches OFF
4) APU select Start & On Busses
5) Bus Transfer switch AUTO
3) Electrical Hydraulic pump switches ON (one at a time)
5) Max APU Start Alt FL250.
6) Declare MAY DAY, if loss of only 1 generator declare PAN PAN.
Looking at the news tonight you would think that no APU or RAM air was available for a 747-400 - is this the case?
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"The only way to survive this scenario, as I understand it, would be to switch off the batteries to preserve the basic standby instruments until within range of an airfield. "
If you switched off the battery on a 744 (whilst down to Battery/Standby Power), you would lose your standby attitude indicator...
The next best thing would be to pull circuit breakers for selected systems (e.g. Do you really need a FMC, more than one IRU, cockpit dome lights, etc...)
I guess you could pull and push in cb's as required (think twice about pulling the IRU DC CB, though )
"Looking at the news tonight you would think that no APU or RAM air was available for a 747-400 - is this the case?"
Can't start the APU in flight on a 747-400 (airplane logic prevents it). On an aviation forum in the dim dark past, someone said they could do it by pulling certain circuit breakers... but I never got around to proving it (using wiring diagrams). Not sure what RAM air is on a 747-400.. unless we are talking about pack cooling??? Not sure how this would save the day, though
Rgds
NSEU
If you switched off the battery on a 744 (whilst down to Battery/Standby Power), you would lose your standby attitude indicator...
The next best thing would be to pull circuit breakers for selected systems (e.g. Do you really need a FMC, more than one IRU, cockpit dome lights, etc...)
I guess you could pull and push in cb's as required (think twice about pulling the IRU DC CB, though )
"Looking at the news tonight you would think that no APU or RAM air was available for a 747-400 - is this the case?"
Can't start the APU in flight on a 747-400 (airplane logic prevents it). On an aviation forum in the dim dark past, someone said they could do it by pulling certain circuit breakers... but I never got around to proving it (using wiring diagrams). Not sure what RAM air is on a 747-400.. unless we are talking about pack cooling??? Not sure how this would save the day, though
Rgds
NSEU
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"Looking at the news tonight you would think that no APU or RAM air was available for a 747-400 - is this the case?"
Correct.
No RAT (Ram Air Turbine)
APU not to be started in flight.
Rgds
N
Correct.
No RAT (Ram Air Turbine)
APU not to be started in flight.
Rgds
N
Psychophysiological entity
Well, perhaps it should be made able to be.
The main issue is attitude. Then navigation Then some sort of communication with ATC.
I've beat a drum on this for years, but a turn and slip with its own battery could have saved several disasters over the years. The first one that I was involved with was the British Eagle Viscount. Total electrical failure: Total loss.
That particular captain loved a challenge, but even he broke the outer wings off doing a cloud break. They didn't quite make it over the top of an autobahn embankment.
A t&S the size of a flashlight, could have saved the day. These days a spare totally independent GPS is obvious. These life saving bits of kit would take up less space than a shaver kit.
I don't know if any GPS will show turn information quickly enough to dispense with the T&S instrument.
I understand some instruments have a back-up battery inside them, but to make long term demands on such a small battery with the load taken by an artificial horizon would be expecting too much.
The main issue is attitude. Then navigation Then some sort of communication with ATC.
I've beat a drum on this for years, but a turn and slip with its own battery could have saved several disasters over the years. The first one that I was involved with was the British Eagle Viscount. Total electrical failure: Total loss.
That particular captain loved a challenge, but even he broke the outer wings off doing a cloud break. They didn't quite make it over the top of an autobahn embankment.
A t&S the size of a flashlight, could have saved the day. These days a spare totally independent GPS is obvious. These life saving bits of kit would take up less space than a shaver kit.
I don't know if any GPS will show turn information quickly enough to dispense with the T&S instrument.
I understand some instruments have a back-up battery inside them, but to make long term demands on such a small battery with the load taken by an artificial horizon would be expecting too much.
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I just read somewhere that the cause of the initial problem was water getting into the generators...now I don't know how all 4 could be lost...but, like murphy said: if it can happen, it will happen.
I hope that we take this situation seriously. It is possible to lose everything...to be down to battery with 45 minutes of power...time to think how to use that time. Over the USA, land at the first available proper airport.
BUT over the ocean, at night, hours from landfall...ouch.
if in the clear, I would get out a mayday, request an intercept and escort and advise powering down and an ETA for the next radio contact. Certainly there are so many concerns and potential scenarios.
There was a delta 767 that had the same problem, crew landed ok. AND YES, the RAT didn't work! 747 doesn't have the RAT to being with.
if NOT in the clear, you have to keep the gyro working somehow.
*(I suppose someone could use the cat system...joke here)
I hope that we take this situation seriously. It is possible to lose everything...to be down to battery with 45 minutes of power...time to think how to use that time. Over the USA, land at the first available proper airport.
BUT over the ocean, at night, hours from landfall...ouch.
if in the clear, I would get out a mayday, request an intercept and escort and advise powering down and an ETA for the next radio contact. Certainly there are so many concerns and potential scenarios.
There was a delta 767 that had the same problem, crew landed ok. AND YES, the RAT didn't work! 747 doesn't have the RAT to being with.
if NOT in the clear, you have to keep the gyro working somehow.
*(I suppose someone could use the cat system...joke here)
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APU
the 747 boys indicate that you CAN'T start the APU in flight.
fine.
CAN you start the APU on the ground and leave it running throughout the flight to supply electrics? air?
just wondering.
fine.
CAN you start the APU on the ground and leave it running throughout the flight to supply electrics? air?
just wondering.
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Qantas Statement on QF2
Sydney, 09 January 2008
Qantas said today the B747-400 aircraft that lost electrical power on descent into Bangkok on 7 January was now back in normal operation.
Qantas Executive General Manager John Borghetti said the pilots had handled this unusual situation in line with their training.
Mr Borghetti said the incident was triggered by water entering the generator control unit, which caused loss of power. The aircraft had automatically reverted to standby power.
"The aircraft was subjected to stringent inspections and testing in Bangkok before being cleared to fly," he said.
"As is normal practice, we are conducting our own investigation as well as working with Boeing, the ATSB and CASA, on their investigations. A more detailed report on the incident will be released by the ATSB in due course.
"As a precaution, Qantas has inspected its entire B747-400 fleet and all of these aircraft have been cleared to fly."
Mr Borghetti said that Boeing, in line with normal practice, would notify all airlines operating B747-400s of what had occurred.
Issued by Qantas Corporate Communication (Q3709)
Sydney, 09 January 2008
Qantas said today the B747-400 aircraft that lost electrical power on descent into Bangkok on 7 January was now back in normal operation.
Qantas Executive General Manager John Borghetti said the pilots had handled this unusual situation in line with their training.
Mr Borghetti said the incident was triggered by water entering the generator control unit, which caused loss of power. The aircraft had automatically reverted to standby power.
"The aircraft was subjected to stringent inspections and testing in Bangkok before being cleared to fly," he said.
"As is normal practice, we are conducting our own investigation as well as working with Boeing, the ATSB and CASA, on their investigations. A more detailed report on the incident will be released by the ATSB in due course.
"As a precaution, Qantas has inspected its entire B747-400 fleet and all of these aircraft have been cleared to fly."
Mr Borghetti said that Boeing, in line with normal practice, would notify all airlines operating B747-400s of what had occurred.
Issued by Qantas Corporate Communication (Q3709)
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So then even if you had the APU up and Running, you would be in the same situation except instead of having four Generaters offline, you would have five generaters...offline.
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I believe that the drip trays located in the fwd MEC failed ( maybe the trays were missing altogether) this should have prevented any water leaking this time from the First Class galley from getting into the electrical system.
Some of the components on those rack are many of the Control units including the Generators Control Units GCUs that would have tripped off line
Boeing believe that there was no requirements for the 400 to be started a APU in flight.
Unlike the B747 classic which some had in-flight start capabilities these had a special air scoop fitted on the APU door,
Some of the components on those rack are many of the Control units including the Generators Control Units GCUs that would have tripped off line
Boeing believe that there was no requirements for the 400 to be started a APU in flight.
Unlike the B747 classic which some had in-flight start capabilities these had a special air scoop fitted on the APU door,
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Quote:
I understand the APU of a 744 is not designed to run inflight.
It runs in flight it just cant be started in flight. An inconvenient difference in this case!
Worth a shot thou if last resort!!!!!!
I understand the APU of a 744 is not designed to run inflight.
It runs in flight it just cant be started in flight. An inconvenient difference in this case!
Worth a shot thou if last resort!!!!!!
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The B747-400 does not have a RAT(ram air turbine).
The APU is available in flight up to 20,000ft.
It cannot be started in flight, only on the ground.
Electrical power is not available in flight, only air to one pack.
There is no total electrical failure check-list.
Standby power from the batteries provides electrical power to the standby compass/standby attitude director/standby ASI, for a minimum of 30 minutes.
If any of the 4 generators would not go back on line, then the crew did an excellent job in very difficult circumstances.
The APU is available in flight up to 20,000ft.
It cannot be started in flight, only on the ground.
Electrical power is not available in flight, only air to one pack.
There is no total electrical failure check-list.
Standby power from the batteries provides electrical power to the standby compass/standby attitude director/standby ASI, for a minimum of 30 minutes.
If any of the 4 generators would not go back on line, then the crew did an excellent job in very difficult circumstances.
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Out of curiousity, does anyone know why the RAT was not installed on the 747? There's one on the 757,767 and 777. Did they think that having 4 engines is enough redundancy making RAT an 'unnecessary' feature?
Then again, Airbus didn't think so with the A340
Then again, Airbus didn't think so with the A340
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A dc standby power system is provided to supply nominal 24 volt dc power to selected flight critical loads for 30 minutes minimum in the event of complete loss of primary dc power. This system is supplied by two 40 ampere hour nickel-cadmium batteries (main and APU battery), associated
battery chargers, various control relays, the main and APU battery hot buses, and main and APU battery buses.
Try and start the APU if possible and you will loose screens etc.
battery chargers, various control relays, the main and APU battery hot buses, and main and APU battery buses.
Try and start the APU if possible and you will loose screens etc.