SQ B777 Engine destroyed during taxi

[Harbour Dweller]

A costly little mistake.

Seems "all clear left" was missed or miscalculated :eek:

Video (https://www.facebook.com/photo.php?v=10151839599552966)


News article (http://www.channelnewsasia.com/news/singapore/engine-of-singapore/928234.html)

[Heidhurtin]

A little embarrassing, but please allow some curiosity from a non-aviation engineering person; who would be ultimately responsible for something like this? I assume the aircraft would be guided into the slot by somebody on the ground, or do the crew roll up to the point without guidance? (I'm not advocating either, I don't have the knowledge to make any judgements here).

[deadcut]

I believe the receiving engineer (or ground handler in other airlines) does a walk around the gate area looking for FOD and I'm assuming ground equipment clearance.

But then again the PIC might be ultimately responsible since he's in command. It was on his side too!

[AndoniP]

if the gate has one of those automated taxi guidance indicators then I assumed it was up to the crew to check that the big area their aircraft is manoeuvring into was all clear? :confused:

[Rwy in Sight]

Fortunately, it was at base hence the disruption could be kept at a minimum.

[emergency000]

It was an empty ULD (Unit Load Device), basically an aluminium and/or plastic container used to transport luggage or freight on the aircraft.

Firstly, it shouldn't have been sitting where it was. The luggage dollies should have been cleared from the bay, for a start. So the baggage handlers are at fault.

Secondly, it should have been noted as a potential hazard before the aircraft arrived. The engineer receiving the aircraft should have carried out a FOD check of the bay, keeping in mind that even an item the size of a ULD is FOD is sucked into an engine or impacted by any other part of the aircraft. The engineer should then have ensured the aircraft didn't attempt to enter the bay until it was clear. I won't bore you, Heidhurtin, with details on how. Suffice to say there are various ways to warn incoming aircraft that the bay isn't clear. So the engineer is partly to blame.

Thirdly, the pilots themselves should make a visual assessment of the bay as they approach to ensure that it looks clear. So the pilots are partly to blame.

Who is ultimately to blame? My two cents is that, until the aircraft shuts down and the chocks are in, the aircraft is the responsibility of the pilot in command. Once its shut down and chocks are in, the engineer takes responsibility.

As we all learn in our human factors training, looks like the holes in James Reason's Swiss Cheese lined up that day.

[One Outsider]

Engine destroyedReally? The bin would have bounced around the intake and against the spinner, possibly also against fan blades, but that's about it.

[PH-Chucky]

Every parkingspot on an international airport should have lines showing which area should be clear of obstacles (cars, pushback equipment, loading equipment.

It is up to the pilots to check if their parkingspot is clear of obstacles when taxiing in. But then again this is dependant on aircraft-size and how well-marked the parking spot is.

I fly the A319/A320 and on many international airports there are loading-cars parked on the area between the parking positions. Within the markings, but well clear of the engines and wing. But again, these are WITHIN the markings.

Once the cockpit has passed the gate, there is no visual anymore with that side of the aircraft. You have to have good judgement on how big your aircraft is, incl distance and power of your engines. The ULD may have been clear of the aircraft, but maybe due some extra power was still sucked into the engine....

At LHR are some fixed bridges that can only move in one direction towards the aircraft. That means that our engines come really close to this fixed structure (1,5 m) without us having visual with it. We have to trust the guide-in system.

Could it be that the guide-in system was programmed for the -300 instead of the shorter -200???

Could it be that the aircraft rolled to far, and thus sucking the ULD into it's engine?

Could it be that the aircraft slowed down to early and needed some extra power on the engines to roll forward, sucking in everything that would normally be no factor?

I would'nt start blaming anyone at all! No-one would like to make this mistake on purpose. First let's find out some facts before bashing anyone.

[west lakes]

Just out of curiosity, should not the PF (or taxiing) or the Capt stopped the taxi, it isn't as if one of them is small and hard to see and is on the Capt's side so could (?) have been spotted (or is visibility that poor when on the ground)

[One Outsider]

should not the PF (or taxiing) or the Capt stopped the taxiWell hello, Sherlock! Is it monday morning there?

[glad rag]

Commanders responsibility.

[Agaricus bisporus]

Simply staggering that anyone would continue to taxi onto stand with a box sitting right there.

OK, someone had left the offending article there so had a causal input, but responsibility for that incident?

100% the "captain".

[Tech_Log]

I would have said joint responsibility between the flight crew and the ground staff.


I would suspect it was getting guided in by an electronic system. As such the pilot was probably focused on this rather than observing the area around the aircraft.
As such yes the commander is responsible and should have stopped the taxi. If in doubt, stop and think.


However you can't attribute their blame without accepting that someone left the ULD there (and it certainly wasn't the flight crew), in a area where it poses a threat and shouldn't be in the first place - both unsafe practises.


Working in a ramp maintenance environment my understanding / belief is that safety is everyone's business and as such, blame can't be shifted because 'I wasn't the last one to touch it' or 'someone else should have seen it'.

[bvcu]

Normally on a stand like this you're following the guidance system. Whoever switched that on is responsible for clearance and should be in position to hit the stop button if something doesnt look right. Same if the guidance isnt working its the marshaller. Shouldnt be the crews fault as they dont have the visibility on most types to assure clearance on a stand with bridges.

[TopBunk]

Ultimately, it is the Captain's responsibility.

Whilst the company may delegate tasks to others, the Captain/flight crew are the only ones who can stop all the holes in the cheese lining up and causing the incident.

As a Captain, if I was unhappy about the positioning of items within the marked areas I would stop and question it, getting positive marshalling guidance if necessary.

On some occasions in a smaller aircraft (B737, A320) I would have been happy to continue with things in the marked area, but was forbidden by company/airport procedures - which I respected - albeit frustrated at times.

On other occasions, as a B744 Captain, I would insist that everything was clear, even if a random individual (ie not a qualified marshaller) told me it was ok.

It was my licence and livliehood at the end of the day.

[Out Of Trim]

Another possibility; is that, the container could have been blown into the Stand area just as the aircraft entered the stand.

If the empty container was not locked onto it's trailer properly, a gust of wind will easily dislodge it and it could go anywhere!

[phiggsbroadband]

I didn't understand the language on the video.. But there was mention of
'engein' quite early on. So they must have spotted the danger but not been in a position to do anything about it.

[hunbet]

They are not the first to do that.

Delta L1011 a few years back.

http://i25.tinypic.com/sf9u9k.jpg

[awblain]

It might have been nice if Mr Lian the videographer had tried doing a charade for "damn big box in the way" as the cockpit approached. Then again… said cockpit was clearly fitted with large windows.

I'm with One Outsider about "destroyed" - I'm sure it'll be very expensive, but even if the fan chipped off bits of box that flew through the fanciest bits of the engine, I'm sure there'll be plenty of bits and pieces that can be saved.

[ExSp33db1rd]

Heidhurtin

Parking at Aero Bridges can be done in various ways. Originally a marshaller would use little flags with recognised "International" signals, i.e. point at the left wheel if that was the one to be braked,(as in the days of tailwheel aircraft with no nosewheel steering i.e. brake the left wheel to turn left ) and eventually cross the arms over the head to indicate "Stop". In later years there was a system of marker boards, with vertical poles in the manner of "transit" lights that yachts can use to follow the centre line of a channel, were used, i.e. a pair of poles to keep on the centre line, and a pair at the side to indicate where stop, and these were occasionally lights showing through slots, these were on the co-pilot side of course, eventually lights were used, in the manner of traffic lights, and the pilot stopped when the red light showed.

Trouble was every Tom, Dick and Harry had invented their pet system, and so it was a lottery as to which system would be in use at ones' arrival airport - there were many variables. In my opinion the very best was used at Miami, it was just a large mirror positioned so that one could actually see ones' own nosewheel, and guide it easily along the centre line until reaching a stop line, which of course was at different distances in for different aircraft. The KISS method.(Keep It Simple, Stupid )

I imagine that Changi being a modern airport there would be a system that left the whole operation to the pilot, but there should still have been "someone" to leap out and manually stop the aircraft in case of failure of the "auto" system. Dunno.

Ironic that the SIA aircraft had come from Bombay, I recall taxying in at Bombay one night, the “stop markers” for the airbridge were the ones at the side, not directly in front. I eventually asked the co-pilot where the ‘stop’ sign was, and then – “Christ ! we’ve passed it” !!

No damage done, but nearly drove No. 2 engine into the bridge ! The first person on the flight deck was a uniformed “official”. who looked out the side and said - with accompanying head wobbling - “ The lights were on, it wasn’t our fault “ . I agreed, but also told him that there was a whole ground crew waiting around the area, and not one had the sense to step forward and wave his hands. They weren’t meant to of course, so probably wouldn’t have in case they were blamed !!

There is no doubt that the rogue container shouldn't have been where it was, but that's a different issue.

[taildrag]

Many years ago at JFK, a Ransome Airlines Nord 262 was taxiing out one dark and windy night. A wheeled luggage cart suddenly surged out of another airline's ramp as they passed by, and struck the Nord behind the wing in the passenger area. I doubt the pilots could even see it. As I recall, there was lengthy litigation about who was responsible for the unsecured cart.
An "act of god?":sad:

[Piltdown Man]

Fault is a rather blunt instrument, even if you can bash a few people at once with it. Whilst it will satisfy the vigilante brigade, it's unlikely to prevent re-occurrence. To achieve that you have to understand what going through the minds of the parties involved. To get understanding, you have to speak with them. And who will speak if you might get blamed? It's like the half-witted public howling for a public inquiry to determine how Event XYZ occurred - so they can blame someone. Unfortunately, wherever and whenever there's blame there will be silence or subterfuge.

Emer000 has identified some of the players but there are bound to be more. If each and every one involved were granted freedom from disciplinary measures, which is does not mean no blame, the real reasons for the incident might be revealed.

[llondel]

That's got to suck :}

Another such incident was the JAL 747 at LAX which was taxiing and a baggage train went past a bit too close.

First hit I found was a Daily Mail story (http://www.dailymail.co.uk/news/article-1180751/Jumbo-Jet-carrying-hundreds-passengers-grounded-baggage-container-sucked-engine.html).

[ironbutt57]

Always refused to park when there was any sort of item inside the "foul line"...

[The FUB]

"Clear on the left everything's behind the line. " Guess this aviator has never flown freight, or looked out of the window to clear the area, with just lip service to calls and probably SOPs as well

[clark y]

Ouch. It's always the Captain's fault (unless he/she can prove otherwise).
As for the engine damage, I'd prefer it to be written off. I wouldn't want an engine on my wing that had history of converting a ULD to CHAFF. Birds do enough damage.
I liked the commentary around the 40 second mark. I only understood two words but I'm sure they were "engine" and "blender".

[Fris B. Fairing]

I couldn't understand most of the video commentary but two words stood out:

"container" and "blender"

Says it all really.

[Alycidon]

The ULD clearly moved toward the aircraft once the aircraft was parked and therefore was not situated a safe distance from the rotating engine. Ground crew were the first hole in the layer of swiss cheese, followed by flight crew being the next layer who may have thought the clearance was adequate but were unaware that the ULD was empty and would be sucked into the engine.

If the ULD had been loaded, it would no doubt have stayed put (assuming that it was parked where the groundcrew normally leave it) and we wouldn't be discussing it here.

Don't know why it was on the LHS though.

[giggitygiggity]

Assuming the captain was following the parking guidance, ignoring who was responsible and who would be responsible if it were to happen again, could the guidance system not scan the protected area to see if anything was there? I mean it is likely something big like a container or vehicle. The technology is surely available!

[Willit Run]

They put windows in these here flying machines for a reason!
This is twice in one week!

[SloppyJoe]

Really? The bin would have bounced around the intake and against the spinner, possibly also against fan blades, but that's about it.

Really? I hope you don't fly planes for a living and are just one of the many uninformed people on this site who wrongly think they know something worth saying about aviation

[Spooky 2]

https://www.google.com/search?q=delta+air+lines+L1011+with+bacggage+container+in+en gine+inlet&biw=1280&bih=597&tbm=isch&source=iu&imgil=pdSf7X5ciWvMDM%253A%253Bhttps%253A%252F%252Fencrypted-tbn3.gstatic.com%252Fimages%253Fq%253Dtbn%253AANd9GcQtNKbDbp b0SbAc8npBLe38LVFC9tfwb39U9Uspy5YGr997X0el%253B640%253B480%2 53BC06GG0Aw3CMQRM%253Bhttp%25253A%25252F%25252Fwww.airliners .net%25252Faviation-forums%25252Fgeneral_aviation%25252Fread.main%25252F890769%2 5252F&sa=X&ei=fj66UsqJOdTpoAT8iICAAg&ved=0CJABEPUBMAw

[One Outsider]

I hope you don't fly planes for a livingOh no! The "I hope you're not a pilot" insult. I'm absolutely devastated now.

But anyway, being a pilot makes you an expert on ULD's in intakes does it? I guess it does since they seem to be the only ones who manages to put them there.
So as a member of the ULD sucking profession is it your expert opinion, based on your ULD sucking experience and a grainy video, that the engine is destroyed?

Then again most pilots know no more about engines than that they become noisier when the throttles go forward and that the little pretty dials then turn clockwise. And that they can be used to vacuum aprons, of course.

[llondel]

So as a member of the ULD sucking profession is it your expert opinion, based on your ULD sucking experience and a grainy video, that the engine is destroyed?

As an engineer, not even one with engines as a speciality, I'd want all the front fan blades checked for minute fractures, as well as the disc, plus a really good check of the rest of the blades for impact signs and a really good check on anything else with impact damage. Most of it will likely be intact, but the check and repair cost may well be rather large.

I might not be an engine expert, but I've read up and seen what can happen starting with the tiniest of cracks. If you're lucky you'll just have a blade come off, and it'll all stay in the casing. If you're unlucky, the disc will fracture and it's pot luck on which direction the high-energy debris will exit the side of the engine.

Then I'd let someone else be the first to run it up, both for the ground test and its first flight.

[phiggsbroadband]

To do a 'Really Good Job' on the engine repair, there is a case to be made for changing BOTH engines...


It avoids any asymmetric thrust problems, and would synchronise the maintenance schedule for the engines.


The plane was most likely in need of an engine change anyway, so do the both whilst it is in the engineering bay. It's a quick fix and the plane is soon back in service.. Any re-usable bits can be held as spares.


Well it is Christmas after all...

[Piltdown Man]

I think changing both engines is a bit over the top. And this won't just be an engine change. The front cowling/s and inlet duct are unlikely to have escaped damage. I also thought it was "an engineering thing" to adjust engines, old, new or in-between, so that that they deliver EPR/N1 values which are not only symmetrical engine to engine but also proportional to thrust lever position, thus avoiding throttle stagger. And is it not a "good thing" that engine maintenance schedules are out of sync? This would mean that similar processes would not occur simultaneously, thus avoiding duplication errors. Also time related failures would be minimised and less likely to occur on the same flight. I also can't see how any parts from a broken engine can be re-released as spares without a manufacturer's approval. But there again, I'm not an engineer!

[nitpicker330]

They WONT change both Engines for gods sake!!!

IF they placed a new/refurbished Engine on the Aircraft and the other is older it only means that the older Engine will suffer with regards to EGT margins. Therefore it will have higher fuel flow and EGT for the same EPR/N1.This will be trend monitored by Engineering data downlinks to stay within acceptable limits.

This happens quite a bit and is nothing we've not seen before on our A330's and 777's. :ok:

Engineering quite often place a notice in the front of the maintenance log for info.

[barit1]

If you're going to replace both jetmotors, replace both aviators as well. No sense taking chances. :rolleyes:

[Machinbird]

Once upon a time,
On a flight line long ago,
An ordnance man held up the safety pins he had just removed from the missile pylons,
And they were promptly sucked out of his hand and down the engine inlet
by the attached fabric streamers.

I had a chance to observe the resulting damage to the engine blading following engine removal.
By far the worst damage was done by the fabric streamers as they caused the blades to untwist as they interfered between rotor and stator blades.

A dissassembled container frequently will contain fabric components, and there is nothing to stop those fabric components from following the airflow.
All you can do is hope that it is only the secondary airflow components that catch the bulk of the FOD because if the core engine catches the FOD, there will be really big $$$$ to pay.

[Capn Bloggs]

To do a 'Really Good Job' on the engine repair, there is a case to be made for changing BOTH engines...

It avoids any asymmetric thrust problems, and would synchronise the maintenance schedule for the engines.

The plane was most likely in need of an engine change anyway, so do the both whilst it is in the engineering bay. It's a quick fix and the plane is soon back in service.. Any re-usable bits can be held as spares.

Well it is Christmas after all...
Nice windup, Father Christmas!

[Mr Mugabe]

Sometimes they leave an empty ULD close to the airbridge for offloading oversized hand luggage, prams etc!

[Capt Groper]

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.

[CodyBlade]

'Get-There-Itis' can cause even Capt. Biggles to miss the Elephant in the room.

There but by the grace of God go I...

[emergency000]

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.

[tdracer]

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. http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/censored.gif 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.

[barit1]

BTW, absolutely no reason to replace the other engine. Operators routinely used 'miss-matched' young and old engines on the same airplane.

Not sure if this practice is still current - but new aircraft with all-zero-time engines will sometimes have a "convenience" removal after a few hundred hours. A perfectly good low-time engine is pulled for "time (cycle) stagger". This helps insure that two (or more) engines don't encounter a future overnight s/b or AD compliance issue at the same time. :ok:

If it's a new fleet, this also can serve as an engine remove/replace training refresher for the hangar crew. :ok::ok:

[nitpicker330]

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.

[JayGatsby]

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.

[Heidhurtin]

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!)

[scrappy1]

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:mad: around. Very unprofessional situation and completely avoidable.

[glbtrtr]

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 ?

[tdracer]

Before blaming everyone maybe you should know what has happened ?


You're obviously new here http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/evil.gif

[scrappy1]

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….

[Yancey Slide]

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."?

[sb_sfo]

Any of you teardown fanatics ever heard of a Borescope - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Borescope)?

[Reverb_SR71]

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

In other words destroyed :} . Bad day to be an insurance company :E .

[glbtrtr]

From the video it is self evident.

The video is showing the consequences of the incident .
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 ?

PS : Once the plane is taxiing in the parking spot it is too late ...
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 ...

[lomapaseo]

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?

not at all correct

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.

[ea306]

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.

[JammedStab]

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.

Now there is a great post. How to prevent such a thing. It is very easy to get very focused on the taxi in. Monitoring ground speed and the marshaller and the centreline. Remember that many times it is the FO taxiing in so the non-taxiing crewmember should be taking extra time to look around.

[767 Super]

In regards to replacing both engines, which I am positive wouldn't happen, the airline I worked for, would require a test flight of the aircraft after a double engine change, on a 2 engine acft.

[Bard39]

Ah! The famous 'head wobbling'.
You were in the right town as the local airline always chose "to fix it in Bombay" as presumably the costs were cheaper ??:ok:

[southern duel]

There is best practise when it comes to aircraft arrivals on stand.

1. the stand entry guidance is only activated once a sweep of the stand/ramp is completed. The guidance systems indicate to a pilot the stand is clear at that time. The correct aircraft type should be visually checked once activated.
2. The pilot should not enter the stand if the guidance is not on or is showing the incorrect aircraft type.
3. the ground handler or a person named by the airline should be in close proximity to the "Emergency Stop" button which is at ramp level.
This is to safeguard the aircraft should anything happen during the aircraft arrival. ALL new guidance systems including Safedock and Apis have this facility. Even the Old Agnis stands can have this fitted and indeed a lot of airports do. Best practise dictates this manned by a nominated person.

The question that needs to be asked are.
1. why was the guidance turned on ?
2. If it was on why does the airline not have a procedure that enables activation of the "Emergency stop"

[grimmrad]

i'd be so pi@#$d if my luggage had been in there. What is the legal situation for the passengers I wonder? Sorry can't find your suitcase, only bits and pieces?

[DaveReidUK]

I think it counts as the airline having lost your bag. :O

[phiggsbroadband]

I think the main points about replacing both engines is..


It does not take twice as long to replace two engines as it does one engine, so the airplane can be back in service sooner.
If there is any performance improvement package available then a matched pair is obviously the way to go.
An engine does not loose its value by being taken off the plane, it is still worth exactly the same in the engineering bay as it is on the pylon.
A spare engine is an asset to the airline, it is an additional economic utility.

[barit1]

Hmmmm.

Twice the labor.
Twice the paperwork (even though paperless)
Test flight required.

Now, I've been away from the industry for a while, but I HAVE NEVER HEARD of any airline changing both engines as a matter of routine practice! :ouch:

But I'm open to updating...

[Airmotive]

It's an SQ 777.
Rolls-Royce and SQ have a joint-venture overhaul facility right there in Singapore (SAESL).
Rest assured, the engine is already torn down and every rotating component is being NDT'ed. Depending on which gas path the FOD took, most likely all the compressor blades are trash...LP, IP and HP. Along with the VIGVs. Each fan blade costs $60K US, BTW.
Turbine blades...who knows. Each one will be FPI'ed to determine if they're "serviceable-used" or scrap. Depending on how many hours are on the blades, some may not be worth keeping in the rotable parts shelf, simply because their life limit would mandate another engine overhaul just to remove the time-expired parts. Ditto all the major bearings.
The inlet duct is part of the basic engine. It will have it's own overhaul and be fitted to another engine when needed.


No double engine changes for crying out loud. For one, it's an SMS issue. Do you really want BOTH engines being replaced on a two-engine aircraft? Never do the same maintenance to both engines at the same time. If, for some reason you MUST do the same mx to both sides, the same person absolutely cannot perform the mx on both sides. In order to reduce the risk of the same mistake being made to both engines and a resulting dual flameout. Basic ETOPs SMS.
Old engines/new engines...they just run at different temperatures to produce the same thrust. Don't they teach that in pilot school?

[r75]

""No double engine changes for crying out loud. For one, it's an SMS issue. Do you really want BOTH engines being replaced on a two-engine aircraft? Never do the same maintenance to both engines at the same time. If, for some reason you MUST do the same mx to both sides, the same person absolutely cannot perform the mx on both sides. In order to reduce the risk of the same mistake being made to both engines and a resulting dual flameout. Basic ETOPs SMS.""
Absolutely,thats been procedure since time began.

[tdracer]

A buddy who works 777 tells me the event engine was a GE90-115B, not a Trent.
Rather amazingly, he says that based on the borescope, there is minimal damage to the core (fan and nacelle were pretty trashed though) .http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/evil.gif
However it sounds like they're going to do a completely overhaul regardless...

[DaveReidUK]

A buddy who works 777 tells me the event engine was a GE90-115B, not a Trent.
Rather amazingly, he says that based on the borescope, there is minimal damage to the core (fan and nacelle were pretty trashed though) .http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/evil.gif
However it sounds like they're going to do a completely overhaul regardless... If your pal has been examining a GE90, it would be amazing if he found any damage at all, given that the aircraft in question was a Trent-powered 777-200ER (9V-SRP, msn 33369).

[tdracer]

Yep, I stand correct - I should have checked the 21.3 report first: Trent 884. http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/puppy_dog_eyes.gif
Obviously my buddy was mistaken...:ugh:

[lomapaseo]

Yep, I stand correct - I should have checked the 21.3 report first: Trent 884. http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/puppy_dog_eyes.gif
Obviously my buddy was mistaken.

How about the damage part? was your buddy right about that part :confused:

[phiggsbroadband]

Was that the same buddy that replaced just one tyre, one sparking plug and one disk-brake pad on your car?

[parabellum]

, it is an additional economic utility.


Try telling that to the bean counters phiggsbroadband, to the bean counters spares on the shelf are a waste of capital and space, particularly if the space is leased. Only bean counters could calculate an 'Allowable time AOG' awaiting spares. According to the BC the money is better off in the bank earning interest than sitting on shelves in the form of spares, even if it does mean the a/c is grounded for a day or two. The engine may be part of a 'power by the hour' agreement anyway in which case SQ will simply want shot of it and a replacement ASAP.


It may turn out to be an interesting insurance claim though, it will hinge on weather the offending baggage container is legally classified as F.O.D. or not. Difficult to call it F.O.D. when it is simply misplaced on the tarmac but still a part of the necessary equipment for the ground handling of that aircraft. Unless the insurance industry has pre written agreements on such incidents, (this won't be the first!), then I see two sets of underwriters possibly going head to head there.

[tdracer]

Was that the same buddy that replaced just one tyre

So, if you get a flat tire on your car, do you routinely replace all four before continuing on? :ugh:

[phiggsbroadband]

Hi Parabellum, I was just thinking that if the engineering crew did not have a spare engine sitting on their shelves, which they could soon put onto the aircraft, then that aircraft is going nowhere for a very long time whilst they replace individual HP turbine blades.
Perhaps some techy types could give us some figures about the time taken to replace an engine, as opposed to testing and replacing internal parts.

[tdracer]

Perhaps some techy types could give us some figures about the time taken to replace an engine, as opposed to testing and replacing internal parts.

Depending on the operator and engine (777 engines, due to their size, tend to take a little longer), an engine change is somewhere between 8 and 24 hours. Some operators routinely do engine swaps during an overnight.
I've never heard of an operator opening up an engine core 'on wing', in a shop it's typically a few weeks, depending on the extent of the work. The newer engines can be broken into modules - fan module, compressor module, hot section module, that sort of thing. If only one module needs work, they'll replace that module (day or two) and return the engine to service while the module in question will go into the shop for overhaul.
If the operator doesn't have an available spare, the engine manufacture typically has several 'lease pool' engines available as spares (although it may take a couple days and a very expensive Antonov charter to get it to where its needed).

[etudiant]

Rebuilding the engine in situ is not happening.
RR has very specific maintenance procedures and doing HP turbine work outside of the shop is not ok.
So an engine replacement seems unavoidable here.
It would be nice to get an update on this from someone on site.

[lomapaseo]

It would be nice to get an update on this from someone on site.

If it was going to a shop for repair it's more than likely that it has already been removed and transported away.

If it's only fan damage (not internal stuff like HP turbine) many engine repairs are often made on wing after a bird strike.

If the shroud casing bits around the fan blade tips are heavily damaged then it just may end up replaced anyway.

Since I haven't seen a photo it aint worth guessing, about the only thing one might hear from the grapevine is whether it was replaced or not.

tdtracer's unreliable friend :E had a very believeable story about the damage so take your pick :)

[phiggsbroadband]

Well guys, if it was aircraft sn 33369 9V-SRP, that aircraft is currently doing SIA 965 Jakata to Singapore, descending past 31,775ft at 433kts.
Perhaps all it needed was a wipe with an oily rag.


See details...
9V-SRP Singapore Airlines Boeing 777-212(ER) - cn 33369 / ln 448 - Planespotters.net Just Aviation (http://www.planespotters.net/Production_List/Boeing/777/33369,9V-SRP-Singapore-Airlines.php)

[DaveReidUK]

Well guys, if it was aircraft sn 33369 9V-SRP, that aircraft is currently doing SIA 965 Jakata to Singapore, descending past 31,775ft at 433kts.It was back in service four weeks ago. And yes, it was 9V-SRP.

[Airmotive]

8 hours to swap a Trent with a good crew. Easy peasy.


Rest assured, SQ would have a 'good crew' at their home base, as well as spare engines. If not, RR is really good about getting engines moved anywhere in the world at any cost to support their big customers. I've witnessed an AN124 get diverted mid-flight to go fetch a Trent from Texas and deliver it to India for a Delta 777. I think they have a 72-hour contractual commitment to get their power-by-hour planes back into the air.


The Trent is the only 777 engine that can fit into a 747F without taking the fan case off. Saves a LOT of time. It slides right in with almost a full inch to spare.
It's fun to watch.