Air France Crash
Posted by: DAVOhorn on 02 June 2009
Dear All,
from what i have heard here on the radio it would appear:
The plane flew near into a fierce storm, severe turbulence reported by flight crew.
Then on board computer sends out electrical failure systems reports.
Plane lost.
This leads me to conclude massive rapid catastrophic cabin decompression leading to instantaneous unconciousness of all on board.
No distress messages were given by flightcrew.
So what could have caused the cabin decompression?
regards david
from what i have heard here on the radio it would appear:
The plane flew near into a fierce storm, severe turbulence reported by flight crew.
Then on board computer sends out electrical failure systems reports.
Plane lost.
This leads me to conclude massive rapid catastrophic cabin decompression leading to instantaneous unconciousness of all on board.
No distress messages were given by flightcrew.
So what could have caused the cabin decompression?
regards david
Posted on: 02 June 2009 by Jonathan Gorse
Dave,
I am not an A330 pilot though do fly another type. I have a feeling that this one may prove rather difficult to solve, not least because the black boxes are probably lying in thousands of feet of water.
However the A330 does have some composite materials in its structure. The composites do not conduct electricity as a metal hull would so have a metallic conductive path installed below their surface. There is a school of thought that it is thus possible that a lightning strike on a composite part may have caused a very rapid temperature rise in that area (due to high electrical resistance). This might have caused the relevant panel to blow out/explode with the potential for decompression.
Alternatively airliners subject to very extreme turbulence may become structurally damaged and this too may of course have caused decompression.
There was a line of severe weather at the time along the ITCZ although the aircraft is fitted with weather radar to allow major cells to be avoided. It isn't foolproof though - I have hit moderate to severe turbulence that wasn't on wx radar at all.
Worth noting though that aircraft are hit by lightning relatively regularly, indeed I was hit on my very first passenger carrying flight over Manchester and the only systems affected were the standby manual compass and one channel on the Captain's nav box - even the autopilot stayed in!! ATC did give us priority straight in at Manch afterwards though because you never know what damage might have been done until the a/c is inspected by engineering on the ground.
Cabin decompression of itself is a perfectly survivable event and crews are trained to get on Oxygen and put the plane into a very high rate of descent to get below 10 000 feet where there is sufficient atmosphere.
Difficult to guess at what may have happened without further information, though the A330 is heavily dependent on electrical power for flight control (which is why it has several electrical systems - engine driven generators, a ram air turbine RAT and batteries for multiple redundancy) Even with no electrics you are still left with horizontal stabilizer for pitch control and the option of differential thrust for roll. This is fine in calm conditions but in a severe storm cell inadequate.
Perhaps the most worrying scenario was that with a storm cell below and a depressurisation as a pilot you're in a no win situation - are you going to descent through the cell? If you try that with reduced flight controls you're in a very desperate situation indeed.
Condolences to everyone involved.
Jonathan
I am not an A330 pilot though do fly another type. I have a feeling that this one may prove rather difficult to solve, not least because the black boxes are probably lying in thousands of feet of water.
However the A330 does have some composite materials in its structure. The composites do not conduct electricity as a metal hull would so have a metallic conductive path installed below their surface. There is a school of thought that it is thus possible that a lightning strike on a composite part may have caused a very rapid temperature rise in that area (due to high electrical resistance). This might have caused the relevant panel to blow out/explode with the potential for decompression.
Alternatively airliners subject to very extreme turbulence may become structurally damaged and this too may of course have caused decompression.
There was a line of severe weather at the time along the ITCZ although the aircraft is fitted with weather radar to allow major cells to be avoided. It isn't foolproof though - I have hit moderate to severe turbulence that wasn't on wx radar at all.
Worth noting though that aircraft are hit by lightning relatively regularly, indeed I was hit on my very first passenger carrying flight over Manchester and the only systems affected were the standby manual compass and one channel on the Captain's nav box - even the autopilot stayed in!! ATC did give us priority straight in at Manch afterwards though because you never know what damage might have been done until the a/c is inspected by engineering on the ground.
Cabin decompression of itself is a perfectly survivable event and crews are trained to get on Oxygen and put the plane into a very high rate of descent to get below 10 000 feet where there is sufficient atmosphere.
Difficult to guess at what may have happened without further information, though the A330 is heavily dependent on electrical power for flight control (which is why it has several electrical systems - engine driven generators, a ram air turbine RAT and batteries for multiple redundancy) Even with no electrics you are still left with horizontal stabilizer for pitch control and the option of differential thrust for roll. This is fine in calm conditions but in a severe storm cell inadequate.
Perhaps the most worrying scenario was that with a storm cell below and a depressurisation as a pilot you're in a no win situation - are you going to descent through the cell? If you try that with reduced flight controls you're in a very desperate situation indeed.
Condolences to everyone involved.
Jonathan
Posted on: 02 June 2009 by Bruce Woodhouse
Jonathan, thanks for your insights.
I have a question re the black-box recorders.
It struck me as almost archaic that we still have to try to recover a physical 'black box'.
Could equivalent continous data from every flight not be transmitted to centralised ground-based recording systems? Or what about a recorder than can be interrogated remotely without having to physically recover it-in other words when it is under the sea?
I appreciate the former system would cease at the point of electrical system failure on the aircraft but would that be any different to the current mechanisms?
Bruce
I have a question re the black-box recorders.
It struck me as almost archaic that we still have to try to recover a physical 'black box'.
Could equivalent continous data from every flight not be transmitted to centralised ground-based recording systems? Or what about a recorder than can be interrogated remotely without having to physically recover it-in other words when it is under the sea?
I appreciate the former system would cease at the point of electrical system failure on the aircraft but would that be any different to the current mechanisms?
Bruce
Posted on: 02 June 2009 by manicatel
Bruce,
my undestanding is that your data sending idea already exists in a basic form on the very aircraft type involved.
Tech issues are "acars'd" back to base every so often (30 mins or so, iirc) for maintanance records.
Also, if memory serves me, the fuselage section of the plane has very little composite material structure, the composite material being used in other areas instead.
Crew are indeed trained to deal with rapid/explosive decompressions, although at altitude, the time of useful consciousness is obviously limited.
Speculation is dangerous in this type of tragedy, but a sudden catastrophic failure, or a problem that the crew thought they could manage, but which suddenly degraded may well have happened, hence the lack of mayday call.
Beyond that, we don't know yet.
RIP.
Matt.
my undestanding is that your data sending idea already exists in a basic form on the very aircraft type involved.
Tech issues are "acars'd" back to base every so often (30 mins or so, iirc) for maintanance records.
Also, if memory serves me, the fuselage section of the plane has very little composite material structure, the composite material being used in other areas instead.
Crew are indeed trained to deal with rapid/explosive decompressions, although at altitude, the time of useful consciousness is obviously limited.
Speculation is dangerous in this type of tragedy, but a sudden catastrophic failure, or a problem that the crew thought they could manage, but which suddenly degraded may well have happened, hence the lack of mayday call.
Beyond that, we don't know yet.
RIP.
Matt.
Posted on: 02 June 2009 by js
My wifes cousin was an airforce test pilots and hates A330s. Said that the fly by wire system can lead to this due to lack of enough manual control in a power fault. The redundancy is almost entirely electrical. Told us this a year or so ago.
Posted on: 02 June 2009 by Jonathan Gorse
Bruce,
Your idea sounds very sensible and not being an expert in this area I have to say I don't know why such a system has not yet been implemented. As Matt says my understanding is that ACARS is the source of automated system failure reports on some aircraft and indeed I presume in this case re: the electrical failures reported.
The A330 in common with many other types including my own does have an ELT (Emergency locator transmitter) which will (If it is still intact) send out a continuous signal for some days powered by its own battery. The purpose of the ELT is to allow wreckage and survivors to be located by satellite. I am unclear of how the range may be impacted by being submerged but judging by the difficulty they seem to be having with locating the wreckage one has to assume in this the case the ELT failed to trigger or was destroyed.
A very sad day for aviation and the families involved.
Jonathan
Your idea sounds very sensible and not being an expert in this area I have to say I don't know why such a system has not yet been implemented. As Matt says my understanding is that ACARS is the source of automated system failure reports on some aircraft and indeed I presume in this case re: the electrical failures reported.
The A330 in common with many other types including my own does have an ELT (Emergency locator transmitter) which will (If it is still intact) send out a continuous signal for some days powered by its own battery. The purpose of the ELT is to allow wreckage and survivors to be located by satellite. I am unclear of how the range may be impacted by being submerged but judging by the difficulty they seem to be having with locating the wreckage one has to assume in this the case the ELT failed to trigger or was destroyed.
A very sad day for aviation and the families involved.
Jonathan
Posted on: 04 June 2009 by DAVOhorn
Dear All,
Heard on the radio here this morning that Air France had had a previous bomb warning earlier this year.
regards david
Heard on the radio here this morning that Air France had had a previous bomb warning earlier this year.
regards david
Posted on: 04 June 2009 by Adam Meredith
Probably not a unique distinction and, as yet, mere fuel to uninformed speculation.
Posted on: 04 June 2009 by SC
quote:Originally posted by DAVOhorn:
...had a previous bomb warning earlier this year.
Probably like most airlines, every working day of the year I should imagine...
Wasn't this one of the first things they ruled out...?
Posted on: 04 June 2009 by Bruce Woodhouse
quote:Originally posted by SC:quote:Originally posted by DAVOhorn:
...had a previous bomb warning earlier this year.
Probably like most airlines, every working day of the year I should imagine...
Wasn't this one of the first things they ruled out...?
....and I bet as soon as it crashed a multitude of groups claimed 'responsibility' too. Such is our world.
Bruce
Posted on: 04 June 2009 by Jonathan Gorse
The thing I find most intriguing is the fact AF came out on the first day and said there was no chance it was a bomb (which struck me as premature frankly) however they are now openly discussing it. There are occasional bomb threats against airlines but they are less common than you might think. There are verification measures in place to assess the validity of the source in collaboration with the security services in order to attempt to eliminate the cranks.
Jonathan
Jonathan
Posted on: 04 June 2009 by Geoff P
It seems Air France has gathered some information reported HERE which paints a pretty grim but not unexpected picture
regards
geoff
regards
geoff
Posted on: 04 June 2009 by u5227470736789439
Very sad indeed ...
Posted on: 04 June 2009 by rackkit
quote:Originally posted by GFFJ:
Very sad indeed ...
That makes grim reading.
On a purely selfish note, it seems that every time i'm about to take a flight somewhere, something like this happens...
Posted on: 06 June 2009 by MilesSmiles
The bodies and belongings they have now found and confirmed to be from AF 447 hopefully helps in the search for the black box.
Posted on: 06 June 2009 by Fraser Hadden
Maybe not much.
Bodies and 'belongings' (a) tend to float, (b) will be released from a cabin breach pretty much wherever it occurs and (c) are prone to drift from the point of release.
The black boxes will in general not be released from the carcass of the aircraft and so will remain on the ocean floor, probably beyond the reach of even a remote submersible - both in terms of depth and the manipulative skill required of the operators to free a black box from the confines of an aircraft. It is a very different order of problem than steering a submersible down the corridors of the Titanic, say - and this latter was difficult enough.
Fraser
Bodies and 'belongings' (a) tend to float, (b) will be released from a cabin breach pretty much wherever it occurs and (c) are prone to drift from the point of release.
The black boxes will in general not be released from the carcass of the aircraft and so will remain on the ocean floor, probably beyond the reach of even a remote submersible - both in terms of depth and the manipulative skill required of the operators to free a black box from the confines of an aircraft. It is a very different order of problem than steering a submersible down the corridors of the Titanic, say - and this latter was difficult enough.
Fraser