BA B777 Incident @ Heathrow (merged)
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IIRC, the 777 MLG failed in exactly the way Boeing intended - it departed the mounts causing minimum or no fuel spill.
Hats off to a resourceful and disciplined BA crew; hats off to the Boeing structures people. All went according to their worst-case plan!
Now then: Recognizing fully that the approach checklist is the fruit of many decades of experience, might it not be prudent in light of Thursday's event to assure that engines have spooled up partway BEFORE lowering gear & landing flaps? That might have given them enough extra L/D to reach the piano keys. Configuring for high drag before assuring available thrust seems, in retrospect, a questionable process.
But then, this was a one-in-many-million case...
Hats off to a resourceful and disciplined BA crew; hats off to the Boeing structures people. All went according to their worst-case plan!
Now then: Recognizing fully that the approach checklist is the fruit of many decades of experience, might it not be prudent in light of Thursday's event to assure that engines have spooled up partway BEFORE lowering gear & landing flaps? That might have given them enough extra L/D to reach the piano keys. Configuring for high drag before assuring available thrust seems, in retrospect, a questionable process.
But then, this was a one-in-many-million case...
None but a blockhead
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The speculation about mobile phones and other handheld devices interfering with avionics has been visited many times on Pprune, so perhaps it might be better to continue it on one of the existing threads (such as this recent one in Tech Log) at least until and if some evidence for this being a factor in the crash comes up.
R
R
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For over 4 years I flew a Citation X, and we knew when someone had a cell phone turned on and on the aircraft because we could hear the "ping" or whatever it is through our headset/intercom.
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" Quote:
You could have a laptop running and a cell phone in every seat and you still would not affect anything on an airplane.
Really? Then how do you explain this?"
Would help if you posted just a small bit of what you're quoting to get even half an idea what you're talking about !
"Called cabin for a check of equipment that may have caused interference. Found passenger seated in first class with laptop on. Model HP6220 with wireless function enabled. The passenger closed the lid when we were boarding on the ground, putting the laptop into standby/hibernate mode.
Once he disabled the wireless function, all OK. The tech people should get a heads-up on this."
Yes, wireless networking may perhaps be more troublesome than cellphones.
You could have a laptop running and a cell phone in every seat and you still would not affect anything on an airplane.
Really? Then how do you explain this?"
Would help if you posted just a small bit of what you're quoting to get even half an idea what you're talking about !
"Called cabin for a check of equipment that may have caused interference. Found passenger seated in first class with laptop on. Model HP6220 with wireless function enabled. The passenger closed the lid when we were boarding on the ground, putting the laptop into standby/hibernate mode.
Once he disabled the wireless function, all OK. The tech people should get a heads-up on this."
Yes, wireless networking may perhaps be more troublesome than cellphones.
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Cell phone interference
The UK CAA ran a research programme into cell phone interference - results are in Paper 2003/3 available on CAA website, and followed by CAA CAP756 - PED's in large transport aircraft. The research showed definite adverse effets on compass and Nav systems under test in laboratory conditions. The worst problems were in the GSM band.
There have been quite a few reports investigated by AAIB etc of compass errors, nav display discrpencies etc attribiuted to such interference.
Not suggesting whatsoever that it has anything to do with this accident, but should alert those who don't believe their phones will have any effect to turn them off when advised by the crew.
There have been quite a few reports investigated by AAIB etc of compass errors, nav display discrpencies etc attribiuted to such interference.
Not suggesting whatsoever that it has anything to do with this accident, but should alert those who don't believe their phones will have any effect to turn them off when advised by the crew.
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Phones
If it is proven that a phone or laptop caused intereference and it crashed, can we be assured that they will be banned? I hear that Ryanair want to allow them. Turns my stomach thinking about it.
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Originally Posted by pasoundman
All software does NOT have bugs. It's entirely possible to write bug free code if the right methods are used.
We should didcuss that somewhere else....
Remember a Mars probe where somebody confused feet and metres?
Bug didn't matter....until the crunch
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For all those that are looking at theories such as lack of fuel or windshear etc. Please stop.
The AAIB have produced a preliminary report, at 600' the engines did not respond to a selection/demand for more thrust. As to what caused that we will continue to speculate.
I personally think the crew did an amazing job.
As for whether 27L was was better than 27R, doesn't 27L have a displaced threshold (LGW operator so don't know)
Hey Shaka Zulu, is that your own personal 777 (just kidding, agree with your post)
The AAIB have produced a preliminary report, at 600' the engines did not respond to a selection/demand for more thrust. As to what caused that we will continue to speculate.
I personally think the crew did an amazing job.
As for whether 27L was was better than 27R, doesn't 27L have a displaced threshold (LGW operator so don't know)
Hey Shaka Zulu, is that your own personal 777 (just kidding, agree with your post)
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Mobile Phone interference
Having lived and flown round China, I always thought the sound of the undercarriage coming down was a cue for all Chinese passengers to turn on their mobile phones.
(Like touchdown is a cue to release seatbelt get up and retrieve handbaggage!)
So, mobile phones are highly unlikely to be connected with this incident else there'd be B777s landing short everyday in the Far East.
I hope I'm right. Else think of the implications...
(Like touchdown is a cue to release seatbelt get up and retrieve handbaggage!)
So, mobile phones are highly unlikely to be connected with this incident else there'd be B777s landing short everyday in the Far East.
I hope I'm right. Else think of the implications...
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Originally Posted by Sallyann1234
GPS is a receiver only - it doesn't transmit.
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Seeing as no one has attempted to answer my question as to exactly where along the runway the glideslope is targeted...
I'll ask it again, please....?
Also, doing a few sums, and taking the figures quoted above, for final (landing) flap setting by 2nm. circa 1000 ft, that leaves approx 20~25 seconds from touchdown...
To the leyman, having to re-adjust (or at least confirm) thrust for new drag/descent rate as late as 20 seconds from touchdown seems these new(?) noise abatement profiles (or are they fuel saving profiles) leave little margin for problems arising after configuration changes...
True/false?
I'll ask it again, please....?
Also, doing a few sums, and taking the figures quoted above, for final (landing) flap setting by 2nm. circa 1000 ft, that leaves approx 20~25 seconds from touchdown...
To the leyman, having to re-adjust (or at least confirm) thrust for new drag/descent rate as late as 20 seconds from touchdown seems these new(?) noise abatement profiles (or are they fuel saving profiles) leave little margin for problems arising after configuration changes...
True/false?
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Some random thoughts:
The press event: I'm sure that the crew didn't enjoy appearing in front of the ravening horde, but I think it was necessary and useful. It has (largely) quelled the 'pilot error' speculation, it has bolstered public confidence and it gave the press something positive to write about. Also, I'd expect it to help morale within BA - who wouldn't want to be associated with such paradigms of aviation excellence?
Ideally, of course, everyone would be happy to wait quietly for information while the professionals went about their business, yet that's not human nature. Press management is a pretty unlovely affair to be engaged in, but it's there for a reason. In passing, I think the crew played their part perfectly and I hope that's inspired at least some of Fleet Street's more unruly element to give them proper respect. That may be an empty hope, but at least it's there.
The flying: Someone mentioned back in the thread the original Captain Prune's advice on taking a prang, find the softest and cheapest object in the vicinity and endeavour to strike it as slowly and gently as possible. I can't think of a better example. From what we know so far, this was consummate airmanship under extreme conditions, when any decision taken another way could and most probably would have resulted in tragedy. I very much look forward to reading the flight crew's own accounts of what happened and their thoughts as they saved the bacon.
The lack of an emergency call: given that the purpose of such a call is to alert everyone to what's happening and get things moving, I don't think it mattered (if it was even an option). If you're about to pancake a 777 into the edge of Heathrow, it's rather likely that you'll be noticed in short order and the correct deductions made! Getting on the blower would have been one of those decisions that could have made things worse.
R
The press event: I'm sure that the crew didn't enjoy appearing in front of the ravening horde, but I think it was necessary and useful. It has (largely) quelled the 'pilot error' speculation, it has bolstered public confidence and it gave the press something positive to write about. Also, I'd expect it to help morale within BA - who wouldn't want to be associated with such paradigms of aviation excellence?
Ideally, of course, everyone would be happy to wait quietly for information while the professionals went about their business, yet that's not human nature. Press management is a pretty unlovely affair to be engaged in, but it's there for a reason. In passing, I think the crew played their part perfectly and I hope that's inspired at least some of Fleet Street's more unruly element to give them proper respect. That may be an empty hope, but at least it's there.
The flying: Someone mentioned back in the thread the original Captain Prune's advice on taking a prang, find the softest and cheapest object in the vicinity and endeavour to strike it as slowly and gently as possible. I can't think of a better example. From what we know so far, this was consummate airmanship under extreme conditions, when any decision taken another way could and most probably would have resulted in tragedy. I very much look forward to reading the flight crew's own accounts of what happened and their thoughts as they saved the bacon.
The lack of an emergency call: given that the purpose of such a call is to alert everyone to what's happening and get things moving, I don't think it mattered (if it was even an option). If you're about to pancake a 777 into the edge of Heathrow, it's rather likely that you'll be noticed in short order and the correct deductions made! Getting on the blower would have been one of those decisions that could have made things worse.
R
but it looked strikingly similar to G-YMMM albeit with different reg.
The instrument touch down point (where the PAR or ILS is designed to make you touch down) is a distance in from the actual threshold of the runway (and for a displaced threshold it's from that)
I don't know the exact distance, and it'll vary depending on the glidepath angle (assume LHR is 3 deg?) but it's about 1000 ft in for a 2.5 deg glidepath - although I'm not normally looking at the distance to go markers at that stage of an approach!
I have the utmost respect for the entire crew of BA038 - they did a fantastic job. Another good reason to fly with a major carrier as opposed to a tin pot one.
I don't know the exact distance, and it'll vary depending on the glidepath angle (assume LHR is 3 deg?) but it's about 1000 ft in for a 2.5 deg glidepath - although I'm not normally looking at the distance to go markers at that stage of an approach!
I have the utmost respect for the entire crew of BA038 - they did a fantastic job. Another good reason to fly with a major carrier as opposed to a tin pot one.
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Harry:
2nm does not equate to 1000 feet. 2nm is 600 feet. 3nm is 900 feet.
2nm/600 feet still leaves 40-50 seconds to touchdown.
There is nothing new about these profiles, nor are they noise abatement nor they fuel saving. They are just bog standard flying.
For the layman, you do not set the thrust a distance X and leave. It is constantly adjusted all the way down to touchdown to compensate for changes in the wind, thermal activity, up and down draughts, turbulence and many other things. To need to go from a low power setting to a higher power or vice versa along the approach path is entirely normal.
2nm does not equate to 1000 feet. 2nm is 600 feet. 3nm is 900 feet.
2nm/600 feet still leaves 40-50 seconds to touchdown.
There is nothing new about these profiles, nor are they noise abatement nor they fuel saving. They are just bog standard flying.
For the layman, you do not set the thrust a distance X and leave. It is constantly adjusted all the way down to touchdown to compensate for changes in the wind, thermal activity, up and down draughts, turbulence and many other things. To need to go from a low power setting to a higher power or vice versa along the approach path is entirely normal.
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As for whether 27L was was better than 27R, doesn't 27L have a displaced threshold (LGW operator so don't know)
An earlier poster also speculated on inset aiming points at LHR for noise purposes. This was also suggested about 2 years ago but thrown out. Perhaps there is now a safety case, as especially 27R has a massive excess LDA over LDR for all types?
Cheers,
TheOddOne