SQ B777 Engine destroyed during taxi
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Red Clearance Lines
The Red Clearance Lines ignored by both the ground staff and flight crew.
The old airmanship calls have slowly been disappearing over the years.
For Example, "Clear Left --- Clear Right & all equipment behind the Line."
I also check and point out in Command training to check the aerobridges are parked in their painter circles indicating correctly retracted. AGNIS or similar electronic guidance doesn't sense the aerobridge positions before activating.
The old airmanship calls have slowly been disappearing over the years.
For Example, "Clear Left --- Clear Right & all equipment behind the Line."
I also check and point out in Command training to check the aerobridges are parked in their painter circles indicating correctly retracted. AGNIS or similar electronic guidance doesn't sense the aerobridge positions before activating.
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Melbourne's aerobridges will inhibit the NIGS if not in their HOME box. More often than not, this leads to we engineers swearing at the bridge drivers because they park them BEHIND the box, meaning we have to marshal the aircraft in by hand. That being said though, obviously every airport is different.
As an engineer, not even one with engines as a specialty
As an engineer with 36+ years with turbine engines as a specialty....
Destroyed may be a bit strong, I probably would have said "trashed", but destroyed is not that much of a stretch.
Even at idle, a 777 fan is turning something around ~600 rpm (I'm guessing Trent here, it would be a bit lower if it was a GE90). At that speed, the impact with a zero rotation ULD is going to rapidly result in much of the container turning into aluminum confetti. The portion of the ULD that survives will bounce into the inlet/fan case, loose rotation, and go back into the fan resulting in more confetti, repeating until the ULD is, well, aluminum confetti.
That confetti will be flung into the fan nozzle/thrust reverser at high speed, doing considerable secondary damage.
If they are really, really lucky, that metal confetti will be centrifuged enough to miss the core inlet. Likely result - a set of fan blades, fan exit guide vanes, inlet, fan case, and thrust reverser will need to be replaced (some bits possibly salvageable, but with major repairs needed).
OTOH, if bits of the ULD went down the core, many of the compressor blades are bent or broken. Best case, secondary damage is minor and limited to the compressor - worst case multiple compressor blades broke off and corn-cobbed the entire core (compressor and turbine).
So, in short, the best case is $1-$2 million in damage, limited to the fan, fan case, and nacelle. More likely, if bits went down the core, the damage is extensive and it could easily be that the engine will cost more to repair than it's worth (sort of like a car - build one from spare parts and a $25k car would cost over $50k) and the undamaged bits will become spares.
BTW, absolutely no reason to replace the other engine. Operators routinely used 'miss-matched' young and old engines on the same airplane.
As an engineer with 36+ years with turbine engines as a specialty....
Destroyed may be a bit strong, I probably would have said "trashed", but destroyed is not that much of a stretch.
Even at idle, a 777 fan is turning something around ~600 rpm (I'm guessing Trent here, it would be a bit lower if it was a GE90). At that speed, the impact with a zero rotation ULD is going to rapidly result in much of the container turning into aluminum confetti. The portion of the ULD that survives will bounce into the inlet/fan case, loose rotation, and go back into the fan resulting in more confetti, repeating until the ULD is, well, aluminum confetti.
That confetti will be flung into the fan nozzle/thrust reverser at high speed, doing considerable secondary damage.If they are really, really lucky, that metal confetti will be centrifuged enough to miss the core inlet. Likely result - a set of fan blades, fan exit guide vanes, inlet, fan case, and thrust reverser will need to be replaced (some bits possibly salvageable, but with major repairs needed).
OTOH, if bits of the ULD went down the core, many of the compressor blades are bent or broken. Best case, secondary damage is minor and limited to the compressor - worst case multiple compressor blades broke off and corn-cobbed the entire core (compressor and turbine).
So, in short, the best case is $1-$2 million in damage, limited to the fan, fan case, and nacelle. More likely, if bits went down the core, the damage is extensive and it could easily be that the engine will cost more to repair than it's worth (sort of like a car - build one from spare parts and a $25k car would cost over $50k) and the undamaged bits will become spares.
BTW, absolutely no reason to replace the other engine. Operators routinely used 'miss-matched' young and old engines on the same airplane.
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BTW, absolutely no reason to replace the other engine. Operators routinely used 'miss-matched' young and old engines on the same airplane.
If it's a new fleet, this also can serve as an engine remove/replace training refresher for the hangar crew.
Mmmmmm, pretty sure we don't do that anymore. Airlines don't normally like Engine changes, costs money and time to change it out and we couldn't possibly do that could we!!
Besides, most Airlines lease the Engines from their manufacturer and "power by the hour" is the catch cry.
Besides, most Airlines lease the Engines from their manufacturer and "power by the hour" is the catch cry.
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tdracer said it perfectly. Mismatched engines are used when required. The same N1 fan speed is commanded, so thrust will be nominally the same (almost all the thrust comes from the fan airflow on a big modern engine). However to achieve that fan speed the core has to work harder in the older engine, because its less efficient - more fuel must be pumped in so the tell tale signs of the old motor are higher temperatures, N2 / N3 core speeds and fuel flow.
Not going to write the usual drivel about 'feel sorry for the guys' etc etc or make worthless guesses about their airmanship - as with the BA incident in JNB - let he who is without sin cast the first stone. We take responsibility for the aircraft even when others are working against us - this happens more often than many outsiders would imagine. Observers only see the occasional dropped ball in this game, but none of the catches.
Not going to write the usual drivel about 'feel sorry for the guys' etc etc or make worthless guesses about their airmanship - as with the BA incident in JNB - let he who is without sin cast the first stone. We take responsibility for the aircraft even when others are working against us - this happens more often than many outsiders would imagine. Observers only see the occasional dropped ball in this game, but none of the catches.
Thanks for all who attempted to answer my (seemingly) simple question. I'm not part of a blame culture - I was only comparing it to my groundside experience - if we have a vehicle which strikes something while being guided (usually reversing), the person doing the guiding is always held to be responsible. The driver/operator is following instructions and it's accepted the "guider" has more awareness and visibility of potential obstacles etc (whether or not the obstacle should actually be there). The "guider" can also move around to look beyond blind spots etc; if he's not sure he stops the vehicle until he is. I've seen marshallers around aircraft, but didn't think of automatic systems at airport gates.
(Before I get trolled - yes, I know large jets are more complicated, harder to manoeuvre etc than a ground vehicle. Also a little more expensive to fix!)
(Before I get trolled - yes, I know large jets are more complicated, harder to manoeuvre etc than a ground vehicle. Also a little more expensive to fix!)
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There were several stages that went awry here.
Firstly the contracting ground handling agent should have done a FOD check and ensure any equipment is outside gate area marking lines.
Secondly the engineering company representative should also have done a quick check and pulled up the ground handling staff who "missed" the equipment or was just too lazy/sensible enough to see the hazard.
Thirdly the pilot should have stopped when approaching the gate and wait until the stand was correctly cleared.
Seems like a complete cluster
around. Very unprofessional situation and completely avoidable.
Firstly the contracting ground handling agent should have done a FOD check and ensure any equipment is outside gate area marking lines.
Secondly the engineering company representative should also have done a quick check and pulled up the ground handling staff who "missed" the equipment or was just too lazy/sensible enough to see the hazard.
Thirdly the pilot should have stopped when approaching the gate and wait until the stand was correctly cleared.
Seems like a complete cluster
around. Very unprofessional situation and completely avoidable.
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For sure someone messed up ...
Mostly an airline does not subcontract in her mainbase ,
Don't know about SQ .
Engineering is in charge of the technical side , not the ramp handling .
Could be different in some stations .
Pilots could have been little tired especially after flying SIN/BOM early morning then not easy to get a good rest .
Before blaming everyone maybe you should know what has happened ?
Mostly an airline does not subcontract in her mainbase ,
Don't know about SQ .
Engineering is in charge of the technical side , not the ramp handling .
Could be different in some stations .
Pilots could have been little tired especially after flying SIN/BOM early morning then not easy to get a good rest .
Before blaming everyone maybe you should know what has happened ?
Before blaming everyone maybe you should know what has happened ?
You're obviously new here
You're obviously new here
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Before blaming everyone maybe you should know what has happened ?
From the video it is self evident.
No one has done anything to stop that situation.
Every station I have worked at normally has a 3rd party ground handling company. They clear the stand and do FOD inspection before the A/C arrives.
The engineer awaiting the A/C, either working directly for the Airline or 3rd party, will ensure the ground handling have done their job correctly and if not, make sure they do. The last thing the engineer wants is an AOG.
Then the A/C can be marshaled onto the stand and parked.
After engine shutdown and beacon off the A/C can be turned around, simples.
This is how a stand should be prepared for the inbound flight.
Of course if this hasn't happened then ultimately the Flight crew should not enter an area they feel is not clear. Swiss cheese and holes syndrome….
From the video it is self evident.
No one has done anything to stop that situation.
Every station I have worked at normally has a 3rd party ground handling company. They clear the stand and do FOD inspection before the A/C arrives.
The engineer awaiting the A/C, either working directly for the Airline or 3rd party, will ensure the ground handling have done their job correctly and if not, make sure they do. The last thing the engineer wants is an AOG.
Then the A/C can be marshaled onto the stand and parked.
After engine shutdown and beacon off the A/C can be turned around, simples.
This is how a stand should be prepared for the inbound flight.
Of course if this hasn't happened then ultimately the Flight crew should not enter an area they feel is not clear. Swiss cheese and holes syndrome….
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Not sure on turbine engines but Lycoming and Continental have sudden-stoppage teardown inspection procedures for the piston stuff. I would presume that GE, PW et al would have FOD inspection procedures for their equipment. What's the alternative, "oh, sucked in a metal box? Too bad, $5m for a new engine please. Don't forget to put what's left of the old one in the recycle bin."?
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Any of you teardown fanatics ever heard of a Borescope - Wikipedia, the free encyclopedia?
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if bits went down the core, the damage is extensive and it could easily be that the engine will cost more to repair than it's worth
. Bad day to be an insurance company 
.
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From the video it is self evident.
Not the causes ...
There is nobody shown , neither engineer , marshaller or ramp people .
Could you say if someone is try to stop the crew from the front side ? no.
Could you say if someone is around the plane ? no .
Could you say what happens in the cockpit ? no .
My previous remark is still valid :
Before blaming everyone maybe you should know what has happened ?
Crew could be set to reach the gate and could little less receptive to a
stop order form the ramp .
Also noone will run to remove the container with mixer grinders on ...
Presumably establishing how lucky they've been means a complete disassembly of then engine down to individual components anyway; that sounds pricey.
And then there's working out a way of properly checking each blade, bearing, shaft, etc. I don't suppose RR or GE have manuals with titles like "How to Check Your Blades/Shafts/Bearings After Throwing Many Kilos of Debris At Them in an Out Of Spec Way". For instance I presume that the shafts have a maximum don't exceed torque rating on them. Can they reliably confirm that hadn't been exceeded in this event?
So presumably there's going to be a large fraction of the engine that will have to be scrapped anyway because it's been operated too far outside of expected operating conditions?
And then there's working out a way of properly checking each blade, bearing, shaft, etc. I don't suppose RR or GE have manuals with titles like "How to Check Your Blades/Shafts/Bearings After Throwing Many Kilos of Debris At Them in an Out Of Spec Way". For instance I presume that the shafts have a maximum don't exceed torque rating on them. Can they reliably confirm that hadn't been exceeded in this event?
So presumably there's going to be a large fraction of the engine that will have to be scrapped anyway because it's been operated too far outside of expected operating conditions?
The manufacturers provide for all manner of inspections and repairs as necessary.
Sure the inspection will go just a tad father than the fan and a nil finding in the front of the aft compressor often means OK to keep it on wing.
About the only time you start worrying about bearings and shafts is if you get an unbalance condition of the size of very large piece of fan blade at high power.
I'm not saying what the exact procedure is for this model, but presumptions in some of these posts is way over the top.
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Not implying any blame on any individuals involved by making the following comment:
More than once when years ago operating as an FO on both wide body and narrow body aircraft I have managed to help us as a crew avoid such collisions with ground equipment by looking both right and left as we approached the gate. The Captain on at least three occasions I can recall was focused on the Docking Guidance System and aligning the aircraft. At the end of long duty days mistakes can and do happen. Not making excuses...but just saying...FO's can be a big help during those last couple minutes of the day.
More than once when years ago operating as an FO on both wide body and narrow body aircraft I have managed to help us as a crew avoid such collisions with ground equipment by looking both right and left as we approached the gate. The Captain on at least three occasions I can recall was focused on the Docking Guidance System and aligning the aircraft. At the end of long duty days mistakes can and do happen. Not making excuses...but just saying...FO's can be a big help during those last couple minutes of the day.
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Not implying any blame on any individuals involved by making the following comment:
More than once when years ago operating as an FO on both wide body and narrow body aircraft I have managed to help us as a crew avoid such collisions with ground equipment by looking both right and left as we approached the gate. The Captain on at least three occasions I can recall was focused on the Docking Guidance System and aligning the aircraft. At the end of long duty days mistakes can and do happen. Not making excuses...but just saying...FO's can be a big help during those last couple minutes of the day.
More than once when years ago operating as an FO on both wide body and narrow body aircraft I have managed to help us as a crew avoid such collisions with ground equipment by looking both right and left as we approached the gate. The Captain on at least three occasions I can recall was focused on the Docking Guidance System and aligning the aircraft. At the end of long duty days mistakes can and do happen. Not making excuses...but just saying...FO's can be a big help during those last couple minutes of the day.