BA 744 Diversion to MAN (Merged)
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Engine has sparks coming out of the back, engine shutdown......no more sparks! I would far rather fly across the atlantic on a 4 engined aircraft with one shutdown, after all the 747 is certified to fly on 3, than undertake a 3hr plus ETOPS diversion on the one remaining engine (aka US airline across the Pacific). Personally, I would say thanks to the BA crew, better Manchester than an extra night in LA!
Warning Toxic!
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Carnage has raised a valid point. If the engine surges and the Exhaust Gas Temperature (EGT) stabilises itself, then it is operated normally, nobody gives it another thought! According to your 'expert NWA Mechanic', it should be shut down and the flight relanded! I regret to say he does not know what he is talking about (or he is aware his airline's long range ops rely on twin engined operations, and it isn't fair that 4 engined aeroplanes don't have to follow the same rules!). He shouldn't be let loose on an aeroplane without a helmet on!
A surge may look quite spectacular- at night it is amazing- flashes of light, sparks flying around- I witnessed multiple surges close up once, at night. If the EGT recovers itself, operate normally! If it doesn't, cut the thrust lever, then if still needed, cut the fuel. In consultation with Maintenance, it is possible they may even suggest relighting it. On the Classic, we used to relight them all the time.
All it means is that a pressure relief valve in the engine is not operating correctly- sticky or something, and suddenly, the engine 'burps'.
A surge may look quite spectacular- at night it is amazing- flashes of light, sparks flying around- I witnessed multiple surges close up once, at night. If the EGT recovers itself, operate normally! If it doesn't, cut the thrust lever, then if still needed, cut the fuel. In consultation with Maintenance, it is possible they may even suggest relighting it. On the Classic, we used to relight them all the time.
All it means is that a pressure relief valve in the engine is not operating correctly- sticky or something, and suddenly, the engine 'burps'.
DOVE
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First of all I’m not exactly a spotter (try to figure out!)
Second: Perhaps I am saying, among the others, the same thing like sombody else:
ETOPS are to be revised some way.
From the BIBLE:
In modern turbofan engines, compressor surge is a rare event. If a compressor surge (sometimes called a compressor stall) occurs during high power at take off, the crew will hear a very loud bang, which will be accompanied by yaw and vibration. The bang will likely be far beyond any engine noise, or other sound, the crew may have previously experienced in service.
Compressor surge has been often mistaken for blown tires, or a bomb in the airplane.
The flight crew, may be quite startled by the bang, and in many cases, this has led to a rejected take off above V1, which have sometimes resulted in injuries, loss of the airplane, and even passenger fatalities.
Compressor stall may be caused by engine deterioration, or may be the result of ingestion of birds, ice, or foreign objects. Its effects may be the final sound from a “severe engine damage”.
In a turbine engine compression is accomplished as the air passes through the stages of the compressor. The air flowing over the blades can stall just like the air over the wing. When this occurs, the passage of air through the compressor becomes unstable and the compressor can no longer perform its duty. This means that there is no more the correct relation between the fuel and the air in the the engine.
Engine surge can be accompanied by visible flames forward out the inlet and rearward out the tailpipe. Instruments may show high EGT, EPR or rotor speed changes.
Depending on the reason for the compressor stall, there many types of surges:
- A single self-recovering surge (the only one I have ever experienced a few times in 40 years, during landing on an MD-80 and the reverse was still deployed by 60 kts)
- Multiple surge prior to self-recovery
- Multiple surges requiring pilot action in order to recover
- A non-recoverable surge
When a compressor surge is not recoverable, the engine will decelarate to zero power as if the fuel had been chopped. This type of surge can accompany a severe engine damage.
Now I am asking:
Who told the crew of BA268, that:
1) There has not been an ingestion of bird/s, pieces of tyre or any other foreign object by the engine number 2?
2) The engine had not been severely damaged?
3) The flames (many feet long) and the sparks (incandescent pieces of metal) did not invest some vital part of the aicraft?
4) One or more of the tyres did not blow out?
5) The cause of the explosions had not been an explosive device?
And all of this is only regarding the beginning of the decision making.
To criticise the rest of the flight is like to shoot at an ambulance.
It is admitted all over the world that a Captain can only claim a stricter airworthiness of his airplane, when it comes to analyse the MELs, to refuel and refill the liquids, to decide if to de-ice or not, etc, than viceversa.
And excuse my ignorance, can I ask if the aircraft and it’s content were still granted by the insurance after the decision to continue to the destination with an engine out? And what about ETOPS license to BA? Safe flight!
Safe flyght to everybody
Second: Perhaps I am saying, among the others, the same thing like sombody else:
ETOPS are to be revised some way.
From the BIBLE:
In modern turbofan engines, compressor surge is a rare event. If a compressor surge (sometimes called a compressor stall) occurs during high power at take off, the crew will hear a very loud bang, which will be accompanied by yaw and vibration. The bang will likely be far beyond any engine noise, or other sound, the crew may have previously experienced in service.
Compressor surge has been often mistaken for blown tires, or a bomb in the airplane.
The flight crew, may be quite startled by the bang, and in many cases, this has led to a rejected take off above V1, which have sometimes resulted in injuries, loss of the airplane, and even passenger fatalities.
Compressor stall may be caused by engine deterioration, or may be the result of ingestion of birds, ice, or foreign objects. Its effects may be the final sound from a “severe engine damage”.
In a turbine engine compression is accomplished as the air passes through the stages of the compressor. The air flowing over the blades can stall just like the air over the wing. When this occurs, the passage of air through the compressor becomes unstable and the compressor can no longer perform its duty. This means that there is no more the correct relation between the fuel and the air in the the engine.
Engine surge can be accompanied by visible flames forward out the inlet and rearward out the tailpipe. Instruments may show high EGT, EPR or rotor speed changes.
Depending on the reason for the compressor stall, there many types of surges:
- A single self-recovering surge (the only one I have ever experienced a few times in 40 years, during landing on an MD-80 and the reverse was still deployed by 60 kts)
- Multiple surge prior to self-recovery
- Multiple surges requiring pilot action in order to recover
- A non-recoverable surge
When a compressor surge is not recoverable, the engine will decelarate to zero power as if the fuel had been chopped. This type of surge can accompany a severe engine damage.
Now I am asking:
Who told the crew of BA268, that:
1) There has not been an ingestion of bird/s, pieces of tyre or any other foreign object by the engine number 2?
2) The engine had not been severely damaged?
3) The flames (many feet long) and the sparks (incandescent pieces of metal) did not invest some vital part of the aicraft?
4) One or more of the tyres did not blow out?
5) The cause of the explosions had not been an explosive device?
And all of this is only regarding the beginning of the decision making.
To criticise the rest of the flight is like to shoot at an ambulance.
It is admitted all over the world that a Captain can only claim a stricter airworthiness of his airplane, when it comes to analyse the MELs, to refuel and refill the liquids, to decide if to de-ice or not, etc, than viceversa.
And excuse my ignorance, can I ask if the aircraft and it’s content were still granted by the insurance after the decision to continue to the destination with an engine out? And what about ETOPS license to BA? Safe flight!
Safe flyght to everybody
A guy I know is a maintenance engineer for United.
He claims to me that the mere characterisation of the engine failure (compressor stall, large flames with sparks, high EGT at idle...) should have been enough by itself to convince the crew to land.
He seems to posit that the crew could not know the aircraft was not suffering from some latent damage and that this is the basis of the FAA's ire.
I am interested to hear responses to this.
He claims to me that the mere characterisation of the engine failure (compressor stall, large flames with sparks, high EGT at idle...) should have been enough by itself to convince the crew to land.
He seems to posit that the crew could not know the aircraft was not suffering from some latent damage and that this is the basis of the FAA's ire.
I am interested to hear responses to this.
The pilot has access to his intruments, sounds and aircraft feel (continous vibration etc.) He is guided to make his judgements based on the symptoms in the cockpit and not some eyewitness imaginative descriptions from the ground.
Second guessing by hear-say does a diservice to the proffesionalism of the flight crew.
Again, I am happy to hear the revelation of facts as discerened by the AAIB or CAA.
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Who told the crew of BA268, that:
1) There has not been an ingestion of bird/s, pieces of tyre or any other foreign object by the engine number 2?
2) The engine had not been severely damaged?
3) The flames (many feet long) and the sparks (incandescent pieces of metal) did not invest some vital part of the aicraft?
4) One or more of the tyres did not blow out?
5) The cause of the explosions had not been an explosive device?
1) There has not been an ingestion of bird/s, pieces of tyre or any other foreign object by the engine number 2?
2) The engine had not been severely damaged?
3) The flames (many feet long) and the sparks (incandescent pieces of metal) did not invest some vital part of the aicraft?
4) One or more of the tyres did not blow out?
5) The cause of the explosions had not been an explosive device?
2) Absence of vibration is a big clue. These things windmill at high speed, physical damage to the engine tends to lead to abnormal vibration levels.
3) Such as what? The engines are out on a pylon. Fuselage damage would lead to pressurisation problems. Fuel tank damage would lead to fuel loss. Hydraulic damage would be evident from EICAS. Damage to the flaps/slats would only be evident on extension, so does it matter whether that occurs at LAX or LHR?
4) See one. EICAS would indicate a tire blow out. Damage to the stab would only be revealed by stab/elevator control problems or fuel leakage from the stab tank.
5)Now you're stretching credulity. Multiple explosive devices? In the engine? Leading to repeated explosions? With no visible external damage to the engine? And no damage to engine probes so no loss of engine data to the EICAS? C'mon.....!
People need to be realistic here. Surges were commonplace in the past. They still occur. People are trained for them. Just because something is less common doesn't mean it's become more dangerous, nor does it give us a reason to start fantastic thought processes about sabotage, FOD, or other weird .
Warning Toxic!
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And excuse my ignorance, can I ask if the aircraft and it’s content were still granted by the insurance after the decision to continue to the destination with an engine out? And what about ETOPS license to BA?
DOVES- you need to read the definition of 'ETOPS', then go to www.Airliners.net and get a picture of a 747 and then count the number of large lumps hanging below the wing!
As the aeroplane was already operating under 3 engines, I don't expect any additional insurance problems occured!
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Clever, very clever indeed
Well, I was GOING to stay out of this as so many opinions have already been offered, but there is one thing I am not seeing.
Here's the deal: In all honesty, how many of you out there who actually leave the ground in control of an aircraft for a living would even THINK of continuing a flight of 10-12 hours after losing an engine just after rotation?
I mean really, just what would the conversation be?
Hmmm....
...Aircraft XYZ, Cleared for takeoff...
Roger, XYZ rolling...
V1....
V2....
Rotate..
KA-BLAM!
Positive Rate, Gear Up, what was that noise?
UM, looks like we lost number 2!
Engine failure checklist....
Hey, what say we see if we can continue home on three?
Hmm, well, if the base says it's OK, why not?
Do any of you see my point? Losing an engine on takeoff, this has to be the FIRST time I ever heard of anyone actually CONTINUING, let alone actually thinking about it.
To those of you out there who are banging the drum that the 747 is certified to fly on three, you have exposed the loophole that will get the crew off the hook.
Yes, the aircraft is certified to fly on three. Three scenarios.
Scenario 1: The aircraft loses an engine on takeoff and returns to the departure airport (after lightening the load).
Scenario 2: The aircraft loses an engine enroute and continues to destination.
Scenario 3: The aircraft has an unserviceable engine and is dispatched on three engines. This is called a ferry flight and requires regulatory approval and the carrier may not carry passengers.
So basically, these guys considered themselves "enroute" and continued after their ground people agreed it was a splendid idea.
Wonderful.
Ten years ago, these guys would have been taken out and keel hauled. Now they are being praised here for their ingenuity.
It comes down to this. Some truths are self evident. The 747 has 4 engines because that was the number that Bill Allen and Juan Trippe agreed on. It is the required number of engines that the engineers designed the aircraft to operate with on a normal basis.
Continuing on three is acceptable so long as one is within a certain envelope. Losing the engine on takeoff is within the envelope for a safe takeoff and subsequent landing at a suitable airfield, but NOT continuing to your destination 10-12 hours away.
Continuing on to your destination after that is bad MOJO. You have ten thousand pounds of sudden extra freight out there and I'm sorry, that just ain't in the plan.
So what it all comes down to is common sense. You lose an engine on takeoff, it's gone, don't work, possible not even there anymore, you return to the departure airport, unless of course, you're in Bahgdad, where these rules do not apply, but that's another topic.
Sorry for the rant folks, just trying to make sense of this one.
PB
Here's the deal: In all honesty, how many of you out there who actually leave the ground in control of an aircraft for a living would even THINK of continuing a flight of 10-12 hours after losing an engine just after rotation?
I mean really, just what would the conversation be?
Hmmm....
...Aircraft XYZ, Cleared for takeoff...
Roger, XYZ rolling...
V1....
V2....
Rotate..
KA-BLAM!
Positive Rate, Gear Up, what was that noise?
UM, looks like we lost number 2!
Engine failure checklist....
Hey, what say we see if we can continue home on three?
Hmm, well, if the base says it's OK, why not?
Do any of you see my point? Losing an engine on takeoff, this has to be the FIRST time I ever heard of anyone actually CONTINUING, let alone actually thinking about it.
To those of you out there who are banging the drum that the 747 is certified to fly on three, you have exposed the loophole that will get the crew off the hook.
Yes, the aircraft is certified to fly on three. Three scenarios.
Scenario 1: The aircraft loses an engine on takeoff and returns to the departure airport (after lightening the load).
Scenario 2: The aircraft loses an engine enroute and continues to destination.
Scenario 3: The aircraft has an unserviceable engine and is dispatched on three engines. This is called a ferry flight and requires regulatory approval and the carrier may not carry passengers.
So basically, these guys considered themselves "enroute" and continued after their ground people agreed it was a splendid idea.
Wonderful.
Ten years ago, these guys would have been taken out and keel hauled. Now they are being praised here for their ingenuity.
It comes down to this. Some truths are self evident. The 747 has 4 engines because that was the number that Bill Allen and Juan Trippe agreed on. It is the required number of engines that the engineers designed the aircraft to operate with on a normal basis.
Continuing on three is acceptable so long as one is within a certain envelope. Losing the engine on takeoff is within the envelope for a safe takeoff and subsequent landing at a suitable airfield, but NOT continuing to your destination 10-12 hours away.
Continuing on to your destination after that is bad MOJO. You have ten thousand pounds of sudden extra freight out there and I'm sorry, that just ain't in the plan.
So what it all comes down to is common sense. You lose an engine on takeoff, it's gone, don't work, possible not even there anymore, you return to the departure airport, unless of course, you're in Bahgdad, where these rules do not apply, but that's another topic.
Sorry for the rant folks, just trying to make sense of this one.
PB
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PB
So was I, but after your post...
Well - that shows how ignorant / unaware / nothing to do with aviation (or certainly this aspect of it) you may be - I do not know. It has long been an established SOP at BA to make a further evaluation after losing 1. Not only has this been done frequently after the last 5+ years, the CAA are fully aware throught the MOR system ands seem happy.
In addition, a long post here recently about a (non BA) -200 (or -300) from MRU that lost one on take-off, and continued to CDG (ORY?) - albeit nearly diverting to NCE for fuel.
And a well publicised CX flight LHR-HKG that lost one over Russia somewhere. Flew 5 hours back to LHR, because that was the best Maint option. Presumably they coud not make the 3 eng Altitude or Fuel reqts for destination, but they still flew past many perfectly good airfields to get back to LHR.
Try reversing the scenario. A 4 Eng aircraft needs 4 Engines to takeoff, because only in that way can it afford to lose 1, and still fly (because basically a 4 Eng aircraft losing 2 on takeoff is not certified to make it in all circumstances). Having got airborne, the situation changes according to weight / speed / altitude / MSA. At this stage, 1 of your engines becomes almost superfluous - because you can go to 2 Engs and maintain a safe altitude, and plan a suitable approach and landing.
It is a "fundamental" of multi engine flying that you always "plan to lose 1" (except in very special circs e.g. 3 Eng ferry) - one which I trust you follow. They followed this. Having "lost 1", the situation was re-assessed, and they could still comply with this basic rule.
The events at MAN were entirely unrelated to the engine failure, or the principle of continuing. They might be interesting, worth evaluating / investigating. However, they do not back up, or denigrate, the decision to continue. However, what they did do was "publicise" the policy, so that people like yourself, and DL at FI, suddenly became aware of something that you previously were not. Whether either you or him you qualified to comment is a moot point.
I am more than happy to debate sensibly such things, and might be convinced that such decisions are not wise. However, after many pages of rants here, I have yet to see 1 decently construted argument as to why they should not have continued... and your post is typical:
Well - most 4 Eng pilots...
Well - what other position did they find themselves in?!*!
Agreed.... and my definition of the envelope is above.
So at what exact point on an LHR-LAX flight does the envelope suddenly become acceptable, in your opinion? 1 hour? 2? 4?
As I say again, there may be good reasons not to have this option / SOP. But nobody has yet presented them here, rather a series of personal "instincts", "insults", "accusations" and uninformed rants, which largely show an ignorance of ULH Ops, but worse, also some blinkered approaches to the basic concepts of multi engine aviation.
Maybe you could just add your qualifications and recent 4 Eng ULH experience... (me - A340 rating some 8 years ago, more recently twin LHS). I note that the airline I flew the A340 for (not BA obviously) had a similar policy - on a transatlantic e.g. ex JFK, if we lost one, the decision to continue or not was based on MSA (not critical) and fuel (maybe critical) on losing a second...
Well, I was GOING to stay out of this as so many opinions have already been offered,
Losing an engine on takeoff, this has to be the FIRST time I ever heard of anyone actually CONTINUING, let alone actually thinking about it.
In addition, a long post here recently about a (non BA) -200 (or -300) from MRU that lost one on take-off, and continued to CDG (ORY?) - albeit nearly diverting to NCE for fuel.
And a well publicised CX flight LHR-HKG that lost one over Russia somewhere. Flew 5 hours back to LHR, because that was the best Maint option. Presumably they coud not make the 3 eng Altitude or Fuel reqts for destination, but they still flew past many perfectly good airfields to get back to LHR.
Try reversing the scenario. A 4 Eng aircraft needs 4 Engines to takeoff, because only in that way can it afford to lose 1, and still fly (because basically a 4 Eng aircraft losing 2 on takeoff is not certified to make it in all circumstances). Having got airborne, the situation changes according to weight / speed / altitude / MSA. At this stage, 1 of your engines becomes almost superfluous - because you can go to 2 Engs and maintain a safe altitude, and plan a suitable approach and landing.
It is a "fundamental" of multi engine flying that you always "plan to lose 1" (except in very special circs e.g. 3 Eng ferry) - one which I trust you follow. They followed this. Having "lost 1", the situation was re-assessed, and they could still comply with this basic rule.
The events at MAN were entirely unrelated to the engine failure, or the principle of continuing. They might be interesting, worth evaluating / investigating. However, they do not back up, or denigrate, the decision to continue. However, what they did do was "publicise" the policy, so that people like yourself, and DL at FI, suddenly became aware of something that you previously were not. Whether either you or him you qualified to comment is a moot point.
I am more than happy to debate sensibly such things, and might be convinced that such decisions are not wise. However, after many pages of rants here, I have yet to see 1 decently construted argument as to why they should not have continued... and your post is typical:
how many of you out there who actually leave the ground in control of an aircraft for a living would even THINK of continuing a flight of 10-12 hours after losing an engine just after rotation?
So basically, these guys considered themselves "enroute"
Continuing on three is acceptable so long as one is within a certain envelope
but NOT continuing to your destination 10-12 hours away.
As I say again, there may be good reasons not to have this option / SOP. But nobody has yet presented them here, rather a series of personal "instincts", "insults", "accusations" and uninformed rants, which largely show an ignorance of ULH Ops, but worse, also some blinkered approaches to the basic concepts of multi engine aviation.
Maybe you could just add your qualifications and recent 4 Eng ULH experience... (me - A340 rating some 8 years ago, more recently twin LHS). I note that the airline I flew the A340 for (not BA obviously) had a similar policy - on a transatlantic e.g. ex JFK, if we lost one, the decision to continue or not was based on MSA (not critical) and fuel (maybe critical) on losing a second...
DOVE
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Rainbowe:
quote:
DOVES- you need to read the definition of 'ETOPS'.
This is exactly what I’m meaning (as you have written so many times: “Now I ask you again to examine flying 3+hours over the Pacific on one engine- and this is accepted as a normal risk of ETOPS (twin) over water, with 300 passengers. What is your opinion of a comparison of the risk?”):
Perhaps time has come to review ETOPS rules”.
Carnage Matey!:
quote:
1)No visual sighting of birds on the take off roll
How do you know? Were you there?
2)Absence of vibration is a big clue. These things windmill at high speed, physical damage to the engine tends to lead to abnormal vibration levels.
I don’t know if tey had vibrations, but for sure it was a ‘non-recoverable surge’ otherwise they didn’t have 1200° EGT and the need to shut down the engine.
3)Such as what? The engines are out on a pylon. Fuselage damage would lead to pressurisation problems. Fuel tank damage would lead to fuel loss. Hydraulic damage would be evident from EICAS. Damage to the flaps/slats would only be evident on extension, so does it matter whether that occurs at LAX or LHR?
You are shooting so many autogoals! What happened if one or more of those problems (a failure to the adjacent engine, a severe fuel or hydraulic leak, a separation of a section of flap, a depressurization) would have happened in the middle of nothing: by the point of ‘non return’ ?
And I have to ask everybody why nobody has commented my assertion:
… that a Captain can only… RISE THE MINIMA, NOT LOWER THEM
DOVE
quote:
DOVES- you need to read the definition of 'ETOPS'.
This is exactly what I’m meaning (as you have written so many times: “Now I ask you again to examine flying 3+hours over the Pacific on one engine- and this is accepted as a normal risk of ETOPS (twin) over water, with 300 passengers. What is your opinion of a comparison of the risk?”):
Perhaps time has come to review ETOPS rules”.
Carnage Matey!:
quote:
1)No visual sighting of birds on the take off roll
How do you know? Were you there?
2)Absence of vibration is a big clue. These things windmill at high speed, physical damage to the engine tends to lead to abnormal vibration levels.
I don’t know if tey had vibrations, but for sure it was a ‘non-recoverable surge’ otherwise they didn’t have 1200° EGT and the need to shut down the engine.
3)Such as what? The engines are out on a pylon. Fuselage damage would lead to pressurisation problems. Fuel tank damage would lead to fuel loss. Hydraulic damage would be evident from EICAS. Damage to the flaps/slats would only be evident on extension, so does it matter whether that occurs at LAX or LHR?
You are shooting so many autogoals! What happened if one or more of those problems (a failure to the adjacent engine, a severe fuel or hydraulic leak, a separation of a section of flap, a depressurization) would have happened in the middle of nothing: by the point of ‘non return’ ?
And I have to ask everybody why nobody has commented my assertion:
… that a Captain can only… RISE THE MINIMA, NOT LOWER THEM
DOVE
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No obvious vibration
2)Absence of vibration is a big clue. These things windmill at high speed, physical damage to the engine tends to lead to abnormal vibration levels.
I don’t know if they had vibrations
I don’t know if they had vibrations
But please bear in mind that, as I said in my first post (on page 27), I was sat over the right wing, not the left wing where the affected engine was. From my side I could neither feel nor see evidence of unusual wing or fuselage vibration, but I don't know for sure about the evidence from the other side of the plane.
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Considerable thread this....
Damage sustained during a full power engine surge does not limit itself to rotating assemblies in the engine, items may be damaged that do not register on vibration measuring equipment.
It should not be assumed that all engine casing damage would exude flames or even gases hot enough to register on the fire/overheat system
A surge at high power after take off is a more considerable event to the engine than a throttle up surge and is rarely caused by compressor bleed valves not opening - at high power they would be closed.
Engines that experience a surge, are subject to internal examination (& external if EGCC) prior to further flight, that is, a surge is not an insignificant event.
Damage sustained during a full power engine surge does not limit itself to rotating assemblies in the engine, items may be damaged that do not register on vibration measuring equipment.
It should not be assumed that all engine casing damage would exude flames or even gases hot enough to register on the fire/overheat system
A surge at high power after take off is a more considerable event to the engine than a throttle up surge and is rarely caused by compressor bleed valves not opening - at high power they would be closed.
Engines that experience a surge, are subject to internal examination (& external if EGCC) prior to further flight, that is, a surge is not an insignificant event.
Yes Terra, there would certainly be too many unanswered questions for my liking!
As the saying goes...I would prefer be on the ground wishing I was in the air, rather than be in the air, wishing I was on the ground!
As the saying goes...I would prefer be on the ground wishing I was in the air, rather than be in the air, wishing I was on the ground!
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As the saying goes...I would prefer be on the ground wishing I was in the air, rather than be in the air, wishing I was on the ground!
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vibration
i would liken the vibration to going over a cattle grid or rumble strips in a car - about 1 or 2 seconds worth of deep vibration. This happened 2 or 3 times over the course of a few minutes and was accompanied by loud bangs.
Warning Toxic!
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Right time to stop this nonsense! Terra, if you are going to talk like an engine expert, I'm afraid you have to put in your profile exactly what your expertise is please and where you obtain such specialised knowledge. I lay my cards on the table as an 34 year airline pilot and 747 Captain. You are just letting us know you are 'UK'!
Where does all this 'wobbliness' come from all of a sudden? According to some of this nonsense here, even a birdstrike anywhere on the fuselage can do some damage 'you might not be aware of', damaging flaps, slats, engines....whatever, so in any birdstrike event we should all dump fuel and re-land? Mr. Boeing makes tougher aeroplanes!
This sounds very convincing until you know more about them:
By the nature of operating a jet engine nearer its limits, surges are more likely. In my experience, they have almost always occured at high power settings, and they have always been absolutely harmless in that although the valve problem may preclude further ooperation, nothing has ever broken during the event. It is simply a 'backfire', 'burp', 'cough' or whatever you wish to describe it! I wouldn't pretend to know whether valves were closed/open when they should have been open/closed- it is immaterial.
If this crew was quite happy to continue, I would place my confidence in them. In exactly the same circumstances, I would continue if the self same happened to me. What we have is a lot of people who don't understand piloting horrified that such things happen (they do), and many twin/trijet pilots with experience of being prepared what a high drama it is losing an engine (especially in a twin, and less so in a trijet) being ready for urgent diversions.
Listen to this- a 747 on 3 engines is equivalent to a trijet. It probably has even more than the standard redundancy of a trijet. It is a positive luxury. We know surges and how to handle them. Why is everyone getting so wobbly about nothing? I'll tell you what would make me wobbly- 1200 miles from a dry landing on one engine working a max power! There is a reason why some airlines operate certain routes with less fuel efficient 747s, and we a have been examining one of them minutely here! Direct your anxiety to operating twins across the Pacific! Do you think it right to fly 300 people on one engine for 3+ hours? Is it acceptable to licence ETOPS operations knowing this will be the outcome of losing just one engine? I tell you, I will never travel that distance from diversions on a twin- that is where the FAA should be examining sensible risk, not a 747 flying on 3 engines. But then I think we understand that the FAA has a very vested interest! 747s are 'old hat' now. Built with strength and redundancy for long ranges like this. The fashion now is twins for everything because they are more fuel efficient. When the first one takes a swim with 300 people, people will be demanding to fly on 4 engine safety. ETOPS is getting beyond sensible risk now....but then it is far more fun to tease here, isn't it?
Where does all this 'wobbliness' come from all of a sudden? According to some of this nonsense here, even a birdstrike anywhere on the fuselage can do some damage 'you might not be aware of', damaging flaps, slats, engines....whatever, so in any birdstrike event we should all dump fuel and re-land? Mr. Boeing makes tougher aeroplanes!
This sounds very convincing until you know more about them:
A surge at high power after take off is a more considerable event to the engine than a throttle up surge and is rarely caused by compressor bleed valves not opening - at high power they would be closed.
If this crew was quite happy to continue, I would place my confidence in them. In exactly the same circumstances, I would continue if the self same happened to me. What we have is a lot of people who don't understand piloting horrified that such things happen (they do), and many twin/trijet pilots with experience of being prepared what a high drama it is losing an engine (especially in a twin, and less so in a trijet) being ready for urgent diversions.
Listen to this- a 747 on 3 engines is equivalent to a trijet. It probably has even more than the standard redundancy of a trijet. It is a positive luxury. We know surges and how to handle them. Why is everyone getting so wobbly about nothing? I'll tell you what would make me wobbly- 1200 miles from a dry landing on one engine working a max power! There is a reason why some airlines operate certain routes with less fuel efficient 747s, and we a have been examining one of them minutely here! Direct your anxiety to operating twins across the Pacific! Do you think it right to fly 300 people on one engine for 3+ hours? Is it acceptable to licence ETOPS operations knowing this will be the outcome of losing just one engine? I tell you, I will never travel that distance from diversions on a twin- that is where the FAA should be examining sensible risk, not a 747 flying on 3 engines. But then I think we understand that the FAA has a very vested interest! 747s are 'old hat' now. Built with strength and redundancy for long ranges like this. The fashion now is twins for everything because they are more fuel efficient. When the first one takes a swim with 300 people, people will be demanding to fly on 4 engine safety. ETOPS is getting beyond sensible risk now....but then it is far more fun to tease here, isn't it?
Last edited by Rainboe; 16th Mar 2005 at 10:13.
Rainboe - well said.
At this rate we will be consulting the tea lady about surges and flying on 3 engines in a 4 jet.
I have been getting more and more concerned about ETOPS operating 3 hours from an airport - in my opinion, it is only a matter of time before somebody gets their feet wet!
At this rate we will be consulting the tea lady about surges and flying on 3 engines in a 4 jet.
I have been getting more and more concerned about ETOPS operating 3 hours from an airport - in my opinion, it is only a matter of time before somebody gets their feet wet!
Too mean to buy a long personal title
DOVES: What happened if one or more of those problems (a failure to the adjacent engine, a severe fuel or hydraulic leak, a separation of a section of flap, a depressurization) would have happened in the middle of nothing: by the point of ‘non return’ ?
I'm happy with that. Flying is safe enough to allow for some things to go wrong and still be safe enough to carry on. I'd really rather have my flights interrupted only when necessary, thank you.
Rainboe: Why is everyone getting so wobbly about nothing?
- It's fun to sex up air safety incidents even when they're nothing to write home about. Some journalists even have to scratch a living out of it.
- It's fun to kick BA. If it had happened on a VS, you can bet that the media would have portrayed the crew as heroes, and it would have been a "story" that never got off the ground.
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The other point I don't think I've seen here is that before they were 'in the wild reaches of the Atlantic/Polar regions etc" the a/c would have been in the air for the considerable time it takes to overland west --> east USA during which time if any problem manifested itself there were multiple diversionary options.
Having flown that far for that long without the "fan damage/bird ingestion/explosive damage" causing any symptoms, they, I presume, felt 100% safe to continue.
Having flown that far for that long without the "fan damage/bird ingestion/explosive damage" causing any symptoms, they, I presume, felt 100% safe to continue.
