Heathrow Airplane Crash!
18 January 2008, 03:44 PM
#122
Scooby Regular
Join Date: Sep 2003
Location: No longer Japan !
Posts: 1,742
Likes: 0
Received 0 Likes
on
0 Posts
As you say B in J, there might be a mechanical reversion to operating the controls if the computerised system failed-like the Tornado in fact, but electro hydraulic power would still be required to operate the control surfaces. The mechanical bit only directs the operation of the control surfaces.
Les
Les
18 January 2008, 03:47 PM
#123
Scooby Regular
Join Date: Dec 2001
Posts: 1,780
Likes: 0
Received 0 Likes
on
0 Posts
Reports i've read say the engines may have gone into reverse at circa 400ft, the engines i believe go into reverse thrust just prior to touchdown automatically.
It was mentioned that if the computer thought the plane was lower than it actually was this would cause the engines to go into reverse.
This would also account for the sudden 'Fall' and witness reports of the engines gunning it.
It was mentioned that if the computer thought the plane was lower than it actually was this would cause the engines to go into reverse.
This would also account for the sudden 'Fall' and witness reports of the engines gunning it.
18 January 2008, 04:00 PM
#124
Scooby Regular
Join Date: Sep 2003
Location: No longer Japan !
Posts: 1,742
Likes: 0
Received 0 Likes
on
0 Posts
Reports i've read say the engines may have gone into reverse at circa 400ft, the engines i believe go into reverse thrust just prior to touchdown automatically.
It was mentioned that if the computer thought the plane was lower than it actually was this would cause the engines to go into reverse.
This would also account for the sudden 'Fall' and witness reports of the engines gunning it.
It was mentioned that if the computer thought the plane was lower than it actually was this would cause the engines to go into reverse.
This would also account for the sudden 'Fall' and witness reports of the engines gunning it.
18 January 2008, 04:01 PM
#125
Scooby Regular
Join Date: May 2004
Location: Ascended to the next level
Posts: 7,498
Likes: 0
Received 0 Likes
on
0 Posts
I too would question its effectiveness at approach speed, as it would be operating close to its minimum operating speed
18 January 2008, 04:02 PM
#126
Scooby Regular
Join Date: Dec 2006
Location: S.E London
Posts: 13,654
Likes: 0
Received 0 Likes
on
0 Posts
18 January 2008, 04:43 PM
#128
Scooby Regular
Join Date: Dec 2006
Location: S.E London
Posts: 13,654
Likes: 0
Received 0 Likes
on
0 Posts
18 January 2008, 04:53 PM
#129
Scooby Regular
Join Date: May 2004
Location: Ascended to the next level
Posts: 7,498
Likes: 0
Received 0 Likes
on
0 Posts
Captain: The co-pilot was landing the plane
<cue interview with 1st officer>
Co-pilot: I thought the Capatin was landing the plane.
Shirley, we're all counting on you
<cue interview with 1st officer>
Co-pilot: I thought the Capatin was landing the plane.
Shirley, we're all counting on you
18 January 2008, 04:55 PM
#130
Scooby Regular
iTrader: (3)
Join Date: Aug 2004
Location: Muppetising life
Posts: 15,449
Likes: 0
Received 0 Likes
on
0 Posts
Its not like they are going to stick their hand up and say "We sold a lot of papers without knowing anything" now is it
18 January 2008, 04:57 PM
#131
Scooby Regular
Join Date: Dec 2006
Location: S.E London
Posts: 13,654
Likes: 0
Received 0 Likes
on
0 Posts
superb!Interesting that its seems like the injuries incurred were during evacuation! Goes to show seatbelts have their uses.
Makes me laugh the number of people who take them off and walk about when the light is on.......
18 January 2008, 05:14 PM
#132
Scooby Regular
Join Date: Dec 2006
Location: S.E London
Posts: 13,654
Likes: 0
Received 0 Likes
on
0 Posts
Excellent simulator demonstration just now. Not sure if they had it planned to end the way it did, but same model plane, same "believed" issue, and the plane came to rest, almost in the same place as in reality.
18 January 2008, 06:28 PM
#138
Scooby Regular
Join Date: Nov 2004
Posts: 2,317
Likes: 0
Received 0 Likes
on
0 Posts
prelim investigation confirms engine fault..
BBC NEWS | England | London | Engine fault caused crash-landing
BBC NEWS | England | London | Engine fault caused crash-landing
18 January 2008, 06:28 PM
#139
Scooby Regular
iTrader: (2)
Join Date: Apr 2000
Location: Bristol-ish
Posts: 2,085
Likes: 0
Received 0 Likes
on
0 Posts
Interesting images of the engines.
It looks like the stbd engine had run down and the port engine was running at low power (if at all) at the point of impact. The damage to the port engine doesn't appear to be consistent with bird ingestion. (Even in the event of a bird strike, the engine wouldn't be shut down by the pilot - the engine control system has surge recovery logic which should recover the engine.)
Thrust reversers cannot be deplyed without a valid weight-on-wheels signal from the aircraft, so that is extreemly unlikely, unless there was a mechanical failure.
From the news, it appears that the engines failed to respond to an increased demand in thrust. This seems very strange if both engines failed to respond, and would indicate either an aircraft control system problem (ie; the aircraft did not demand more thrust), or some problem with the delivery of fuel to the engines (the engines were trying to spool up, but there was insufficient fuel).
It looks like the stbd engine had run down and the port engine was running at low power (if at all) at the point of impact. The damage to the port engine doesn't appear to be consistent with bird ingestion. (Even in the event of a bird strike, the engine wouldn't be shut down by the pilot - the engine control system has surge recovery logic which should recover the engine.)
Thrust reversers cannot be deplyed without a valid weight-on-wheels signal from the aircraft, so that is extreemly unlikely, unless there was a mechanical failure.
From the news, it appears that the engines failed to respond to an increased demand in thrust. This seems very strange if both engines failed to respond, and would indicate either an aircraft control system problem (ie; the aircraft did not demand more thrust), or some problem with the delivery of fuel to the engines (the engines were trying to spool up, but there was insufficient fuel).
18 January 2008, 06:32 PM
#140
Scooby Regular
iTrader: (2)
Join Date: Apr 2000
Location: Bristol-ish
Posts: 2,085
Likes: 0
Received 0 Likes
on
0 Posts
prelim investigation confirms engine fault..
BBC NEWS | England | London | Engine fault caused crash-landing
BBC NEWS | England | London | Engine fault caused crash-landing
18 January 2008, 06:37 PM
#141
Scooby Regular
Join Date: Nov 2004
Posts: 2,317
Likes: 0
Received 0 Likes
on
0 Posts
Ok - the engines didn't respond to auto pilot and pilot demand..
The AIBB report in full quoted on the BBC
BBC NEWS | England | London | In full: AAIB initial statement
The AIBB report in full quoted on the BBC
BBC NEWS | England | London | In full: AAIB initial statement
18 January 2008, 06:49 PM
#143
Scooby Regular
Join Date: Aug 2006
Posts: 990
Likes: 0
Received 0 Likes
on
0 Posts
18 January 2008, 07:36 PM
#144
Scooby Regular
Join Date: Sep 2003
Location: No longer Japan !
Posts: 1,742
Likes: 0
Received 0 Likes
on
0 Posts
So they seem to have ruled out any climatic reasons, crew error and bird strikes. So that just leaves some sort of system malfunction.
They said the engines didn't respond, which suggests they were still spooling (as opposed to having stopped altogether). The pictures show the RAT, but was that because it had been deployed (either automatically or commanded by the aircrew) or is that just a result of the impact?
The engines have different power supplies, different fuel sources, different FADEC's, each with multiple channels, independent computer hardware supplied with independent electrical sources and independently derived software and commanded by the throttles which have multiple redundant RVDT's.
It shouldn't be possible to effectively lose both at the same time. Lot's of late nights in store for the engineers and investigators to find out the cause quickly, there's several hundred B777's in the air at any given time.
They said the engines didn't respond, which suggests they were still spooling (as opposed to having stopped altogether). The pictures show the RAT, but was that because it had been deployed (either automatically or commanded by the aircrew) or is that just a result of the impact?
The engines have different power supplies, different fuel sources, different FADEC's, each with multiple channels, independent computer hardware supplied with independent electrical sources and independently derived software and commanded by the throttles which have multiple redundant RVDT's.
It shouldn't be possible to effectively lose both at the same time. Lot's of late nights in store for the engineers and investigators to find out the cause quickly, there's several hundred B777's in the air at any given time.
18 January 2008, 07:40 PM
#145
Scooby Regular
Join Date: Oct 2003
Location: Runway two seven right.
Posts: 6,652
Likes: 0
Received 0 Likes
on
0 Posts
Purely guessing but I think may be a 1 in a million/billion ( pick any number you like ) system malfunction. Be interesting to see if the FDR has picked up the cause. If not, as B_in_J said, some long nights ahead for Boeing engineers.
18 January 2008, 08:47 PM
#146
Scooby Regular
Join Date: Feb 2003
Location: Zed Ess Won Hay Tee
Posts: 21,611
Likes: 0
Received 0 Likes
on
0 Posts
18 January 2008, 10:16 PM
#147
Guest
Posts: n/a
Heathrow BA 777 Plane Crash Pilot Tells What Went Wrong |Sky News|UK News
2 miles out both engines fail while on a normal descent rate, no wonder the 1st Officer is getting massive praise for getting it as close to the runway as he did
At that point there must be a very fine line between getting the nose up to prolong the descent and stalling it.
I just don't know how anyone in that situation can not have a brown trouser moment.
2 miles out both engines fail while on a normal descent rate, no wonder the 1st Officer is getting massive praise for getting it as close to the runway as he did
At that point there must be a very fine line between getting the nose up to prolong the descent and stalling it.I just don't know how anyone in that situation can not have a brown trouser moment.
