Final report on CX780 accident published

[hkgmjq]

English isn't perfect, but makes for interesting reading nevertheless.

Link to page:

Civil Aviation Department - Reports (http://www.cad.gov.hk/english/reports.html)

Link to report .pdf:

http://www.cad.gov.hk/reports/2%20Final%20Report%20-%20CX%20780%202013%2007%20web%20access%20compliant.pdf

[lomapaseo]

As usual an excellent investigation and report.

I sense three areas that might elicit discussion on this board since no design changes are anticipated to eliminate this type of failure.

The continued possibility that fuel contamination may occur in the future if the fueling recommendations are not adhered to.

The minimal actions that the crew may employ in some phases of flight if the contamination should cause a sudden onset of engine control problems.

The mechanism on how this type of contamination affects engine control systems.

The last item is probably only suitable in a tech forum.

[BARKINGMAD]

Refer to "B737 Smoking Brakes Scenario."

Then think of the casualties after this evacuation.

Fire dept attacking hot brakes with water, I think not! Classic formula for exploding tyres/wheels is NOT the environment in which to deposit the passengers.

Can we PLEASE think again on the criteria for chucking the pax down the slides and into hospital?!?! :ugh:

[hkgmjq]

I don't wish to get drawn into a wider discussion on when/when not to evacuate, but I think it's worth pointing out that while on paper 62 pax and crew were injured during the evacuation, only one of those required hospital treatment for a broken ankle.

[framer]

Wow that was a good outcome from a tricky situation.
Thanks for posting it.

[nitpicker330]

Yep, our boys did well. I could only hope to perform as well in the future and fingers crossed I won't have to. :ok:

[ExRR]

I'm curious as to the lack of any consideration or discussion in the report of the decision (however right or wrong) to have continued the flight to destination with faults showing on engines and one engine ineffective relatively early in the flight.

[Sqwak7700]

I'm curious as to the lack of any consideration or discussion in the report of the decision (however right or wrong) to have continued the flight to destination with faults showing on engines and one engine ineffective relatively early in the flight.


I'm curious about your lack of reading skills. Obviously you did not read the report, as those questions are addressed several times in the report.

Troll much? :hmm:

[Basil]

Phew! Reckon my pulse went up a bit as I read the History of the Flight.
I'd like to hear from the pilots themselves on the QT if, after years of hindsight, there's anything (or nothing) they'd have changed in the way they handled a not at all straightforward situation.
Well done - but, of course, that's what we expect from CX crew :ok:

[ROSUN]

Well handled by the crew from reading the report.
One surprising factor was the relatively high percentage of injuries to the crew from the disembarkation, who you would think would be more practised in this exercise. The report does not go into detail of the way the injuries were sustained but I suspect they were collision injuries due to a failure of the passengers to move away from the base of the slide after evacuating the aircraft, something that rarely occurs in training and currency checks.

[J.O.]

I know I'm swimming upstream but I really hope we can avoid the typical PPRuNe second guessing of the crew's actions that usually accompany such reports. Those boys did a whale of a job in a situation none of us has ever even contemplated, never mind being trained for it. :ok:

[Huck]

Tell me again about the coming wave of remotely-piloted airliners.....

[Killaroo]

Why didn't he shut down that one stuck at hi power?
Seems like a no brainer, duh!

[Morav]

Great flying, job well done!

[CodyBlade]

Superb bit of technical writing, even I understood it.

[noughtsnones]

Killaroo,
The earlier publication “Accident Bulletin 1/2011 (An update Bulletin to Accident Bulletins 1/2010 and 3/2010)”
includes a paragraph 5, copied below (my bold):
“5. At 0530 hr, the ECAM caution message “ENG 1 STALL” was annunciated. The commander moved the No. 1 thrust lever to idle position. He then tested the engines by gently advancing and retarding the thrust levers. However, only No. 1 engine responded with stepped increase in N1 and did not reduce when the thrust lever was retarded. No. 2 engine remained at idle during the test. In an attempt to recover No. 2 engine control, the crew carried out a shutdown and restart on No. 2 engine in accordance with the Flight Crew Operating Manual (FCOM) procedures. However, the engine could only operate at sub-idle condition for the remainder of the flight. The No. 1 engine was stuck at approximately 74% N1 during the approach and reduced to about 70% N1 at touchdown. The No. 2 engine remained stuck at about 17% N1 throughout the approach and landing.”


One can only speculate as to the engine delivered and aircraft required thrust behaviour and consequences that would occur if Engine 1 had also been shutdown.


J.O. said it rather well Those boys did a whale of a job in a situation none of us has ever even contemplated, never mind being trained for it.

[FANS]

When reading it one has to remember that if you were in that situation, you don't know what will happen next and No. 1 engine may have decreased down to 17% or lower at any point.

You've no idea why what's happened has happened, and you don't know how much worse it may get. Hand flying under that pressure is hard work, when you're so focused on the why and what next.

[BOAC]

required thrust behaviour and consequences that would occur if Engine 1 had also been shutdown. - not much to 'speculate' on, really - it would probably have crashed.

A great piece of flying in circumstances that must have been very difficult to determine.

[ExRR]

Sqwak7700

I'm curious as to the lack of any consideration or discussion in the report of the decision (however right or wrong) to have continued the flight to destination with faults showing on engines and one engine ineffective relatively early in the flight.
I'm curious about your lack of reading skills. Obviously you did not read the report, as those questions are addressed several times in the report.

Troll much?

Thank you for your concern. Well my reading skills aren't what they used to be when I worked on the design of the RB211 forty odd years ago, and I'm not trolling.

It's a long report, I've not read every word. I see the first maintenance engineer gave advice and based on that the crew made the decision to continue. By the time ME2 was involved VHHH was clearly the only possibility. I still haven't found any discussion - just a one liner "reasonable". Maybe no more needs to be said.

Much trust in one engine flying. Pleased to have been involved in the early stages of design of such a reliable power plant. However, for right or for wrong I would have been very tempted to head straight for Singapore. In hindsight the decision to continue to destination proved to be problematic. Maybe I'm being oversensitive living just a stone's throw from Kegworth.

[Dan Winterland]

I'd like to hear from the pilots themselves on the QT if, after years of hindsight, there's anything (or nothing) they'd have changed in the way they handled a not at all straightforward situation.

I think in hindsight, they would have landed ASPAP (Red!). However, they didn't know what was going on or how serious it was at the time, and I'm not sure I would have handled it any differently.



But, it was very well handled. Good show chaps! :ok:

[rick.shaw]

Killaroo. No - it wasn't a no brainer - duh.....

Barking mad. On the ground in an emergency situation, I would far rather risk a few injuries down the slide than having my passengers trapped on a burning or smoke filled aircraft. Just look at the video of the 737 at Naha some time ago. If they had rethought that for just a minute longer, there may have been a very different outcome. The downside risk of SERIOUS injuries during an evacuation is very small. So, no - I will not rethink my thinking on this matter.

[Ozlander1]

I wonder why other aircraft were not affected by the contaminated fuel.

[HDRW]

I wonder why other aircraft were not affected by the contaminated fuel.

Well the same flight the day before, was! Nowhere near as badly, obviously. They do seem to have discontinued use of that fuelling equipment as soon as the problem was suspected, limiting further possible problems. Maybe the vibration that happened while refuelling dislodged a lot of the spheres - many more than smooth flow would have. I remember years ago testing air filters, and just tapping them lets a lot of the trapped particles loose into the air, and having pulsed air flow really made them fly. Rather like the difference between placing a hammer on a nail, and hitting it repeatedly. It seems this is a very rare occurrance, and maybe the design of the affected parts makes them susceptible, while other engines may not have been affected as badly, or at all.

[tdracer]

I wonder why other aircraft were not affected by the contaminated fuel.

It could also be that also be that there is something about the A330 and/or the Trent 700 that makes it susceptible to that particular type of contamination. I doubt they get a lot of A330 traffic in/out of Surabaya

I know that the Rolls RB211-524G/H controls on the 767 and 747-400 were very sensitive to fine particle contamination.

[JPJP]

I thought the crew did an outstanding job. Some small details that showed some excellent skills:

1. When it became obvious that they had both engines indicating 'stall', the commander traded excess airspeed for altitude. A small detail, but an action that shows excellent situational awareness.

2. Turned off the flight director and hand flew the aircraft when appropriate.

3. Managed excess energy using 'S turns' on final.

4. Whilst hand flying under unusual circumstances, realized that he'd called for the incorrect bearing intercept for the ILS and corrected it.

A 35 year old Commander and a 37 year old F.O. that showed they weren't children of the magenta line. Nicely played.

[lomapaseo]

I know that the Rolls RB211-524G/H controls on the 767 and 747-400 were very sensitive to fine particle contamination.

and so are most of the new FADEC controlled engines on all model types.

It's the fuel metering concept that requires close clearances, not-too-tight and not-too-loose, just like a musical valve instrument.

Please don't open one up when not in a clean room.

Screens are fine, except when the contamination is created from a dissolved substances into a particle after it passes through the screen.

Nothing left but trust in the fuel as well as the crew.

[tdracer]

and so are most of the new FADEC controlled engines on all model types.

It's the fuel metering concept that requires close clearances, not-too-tight and not-too-loose, just like a musical valve instrument.

ALL fuel controls - FADEC and pure Hydromechanical - are sensitive to contamination - lots of moving parts with tight clearances. The RB211-524G/H was much worse due to even tighter clearances than is typical for most controls. Lucas (now part of Goodrich) liked to use much tighter clearances for their valves than the other guys, and it caused problems the others didn't see.

OTOH I know very little about the Trent 700 - I don't even know who supplies their Fuel Metering Unit (i.e. is it the company formerly known as Lucas, or is it someone else).

[Willie Nelson]

I was interested to read that Airbus revised the QRH to provide a suspected fuel contamination and a fuel contamination checklist for the the 330.

I operate the 320/321 IAEs and I wondered why said aircraft was not included in this style of checklist, upon looking at ENG 1(2) FUEL CTL FAULT I think I [I]may[I] have found the reason, I shall leave it for others to determine.

Worth a look in your Abnormal checklist.

[JammedStab]

I'm curious as to the lack of any consideration or discussion in the report of the decision (however right or wrong) to have continued the flight to destination with faults showing on engines and one engine ineffective relatively early in the flight.

I think it may have crossed the minds of the crew to divert based on the report. So they were making these considerations.

"During the climb, the flight crew noticed some abnormal Engine Pressure Ratio (EPR) fluctuations on No. 2 engine, with a range of approximately ± 0.015 around EPR target. No. 1 engine also had abnormal EPR fluctuations but within a narrower range."

"shortly after levelling off at FL390 (i.e. 39,000 ft AMSL at standard atmosphere conditions), Electronic Centralised Aircraft Monitoring (ECAM) message “ENG 2 CTL SYS FAULT” was annunciated. ECAM information “ENG 2 SLOW RESPONSE” was shown for crew awareness."

"The maintenance engineer (ME1) at the IOC asked the flight crew to check the responses of the engines to thrust lever movements. The flight crew advised that the EPR was fluctuating around an EPR target."

"As all engine parameters were considered normal other than the EPR fluctuations, the flight crew elected to continue the flight to Hong Kong."

"At 0316 hrs, ECAM message “ENG 2 CTL SYS FAULT” reappeared when the aircraft was levelling off at FL380. This time ECAM information “AVOID RAPID THR CHANGES” was also displayed in addition to the “ENG 2 SLOW RESPONSE”."

"The flight crew called MC again via SATCOM for further discussions. Another maintenance engineer (ME2) responded to the call and confirmed that he was aware of the earlier situation as they had been monitoring the engine parameters during the flight. The flight crew, with more concern this time, reported the ECAM message and the observed increase in EPR fluctuation (± 0.1 for No. 2 engine and ± 0.03 for No. 1 engine). The flight crew queried whether it was safe to continue the flight."

"Significant windshear was forecasted for both runways 07L and 07R."

[Sqwak7700]

It's a long report, I've not read every word. I see the first maintenance engineer gave advice and based on that the crew made the decision to continue. By the time ME2 was involved VHHH was clearly the only possibility. I still haven't found any discussion - just a one liner "reasonable". Maybe no more needs to be said.

Might be long, but this statement makes some pretty large assumptions:

I'm curious as to the lack of any consideration or discussion in the report of the decision (however right or wrong) to have continued the flight to destination with faults showing on engines and one engine ineffective relatively early in the flight.

Your questions are answered in the report. The engines where not "ineffective". They were both producing cruise thrust and the crew carried out several tests to ensure they were functioning normally. When they carried out the step descent, the engines responded normally as well. Being a fuel contamination problem, I think this sort of issue grew in severity as the flight progressed, and became a real problem only upon arrival at their TOD.

And the decision to continue was talked about in several parts of the report, and deemed completely safe and appropriate. That is what led me to question your insinuation that it was not.

You an I can sit here with the knowledge of "fuel contamination blockage caused by SAP spheres", but they did not have that knowledge at the time. All they had where some ECAM messages for which they followed their QRH and discussed with engineering for further insight.

[nitpicker330]

Ignore the "significant Windshear forecast,......" etc etc as that appears on most days in VHHH :eek:

[ExRR]

and one engine ineffective relatively early in the flight.

Apologies - that was a misread of the timing of events on skimming through.

[lomapaseo]

I believe that we're missing the essence of the event when we start discussing should-ofs, could-ofs regarding crew actions.

The threat from the contamination is not steady state cruise but any throttle dithering that exercises the valving in the fuel control to either stick up or down or in some cases advance on its own to max thrust without response to the throttle position.

[misd-agin]

JPJP -
A 35 year old Commander and a 37 year old F.O. that showed they weren't children of the magenta line. Nicely played.



A/P on at 1144'. Daytime departure. :{

[Tray Surfer]

Fascinating reading.

All be it, I don't understand a lot of the technical stuff, but still very interesting to read.

[avturboy]

An interesting thread for sure but among all the comments made I'm surprised that there is almost no mention of the root cause of the incident and what can be done to prevent re-occurrence, i.e. fuel contamination.

[JPJP]

A/P on at 1144'. Daytime departure.

Ha :p

Yeah. I noticed that. Perhaps the FO had been hand flying the aircraft so much he decided that some automation familiarization was in order ....

The point of the Magenta Line syndrome isn't the fact that familiarity with automation is inherently dangerous. It's the danger of a degradation of other abilities as a result of it. In this case, I think the Commander showed that there was no degradation of his ability to aviate. When 'push came to shove', he still knew what he was doing.

[Huck]

Widebody captain at 35? That's a fairy tale over here....

[Veruka Salt]

The F/O was previously an F18 driver then Learjet/Westwind target tow pilot prior to joining Cathay, so I don't doubt his ability to hand fly an Airbus.

[Sqwak7700]

I'm surprised that there is almost no mention of the root cause of the incident and what can be done to prevent re-occurrence, i.e. fuel contamination.

There is if you read the report. From what I understood, as in most accidents, it was a chain of events. Contamination of salt water from some relief ponds in the airport managed to get into the airport's refueling system when it was being worked on during a parking ramp extension.

The contaminants blocked the filters, and the fueling company just pumped up the pressure instead of investigating the reason for reduced flow. This pressure exceeded the inner metal structure design limits of the filtering cartridge, causing it to collapse and bulge slightly, creating more restriction.

The saltwater in the system affected the integrity of the filtering material, which then released the globules into the fuel flow. These spheres where small enough to not be detected during visual inspections, and caused FCU malfunctions after prolonged operation which allowed excessive buildups to block moving components.

There were plenty of recommendations to all parties, and the filter manufacturer improved the design of their system. Overall, I think the fault lies on the airport operator for sloppy construction practices followed by sloppy inspection and flushing of the system. The fueling operator also suffered from a bit of sloppiness in not investigating the blockage causing the pressure drop.

[lomapaseo]

There were plenty of recommendations to all parties, and the filter manufacturer improved the design of their system. Overall, I think the fault lies on the airport operator for sloppy construction practices followed by sloppy inspection and flushing of the system. The fueling operator also suffered from a bit of sloppiness in not investigating the blockage causing the pressure drop.

A fair summary :ok:

my problem with all this is that the large transport aviation community doesn't really have a regulation in their books that covers all this, thus the recommendations are just that, no hope of being mandatory.

[avturboy]

Sqwak7700,

Sorry didn't phrase my point very well, I've read the report and yes there is a considerable content about how the fuel contamination occurred.

What I meant to say was that there hadn't been much comment in this thread.

[Sqwak7700]

What I meant to say was that there hadn't been much comment in this thread.


Would be interesting to find out how the same contaminant affects different engine types. There are plenty of other operators in Surabaya, I wonder if they had any issues. Plenty of 330s as well (I can think of a few of the top of my head like GIA, SIA, MAS, EVA, CAL).

You would think something so small to pass through on-board filters would just burn int he can instead of lodging and disturbing the peace inside the FCUs. Must be some pretty tenacious stuff, surely there is other material that can be used as a filtering medium?

[crwkunt roll]

The flight crew queried whether it was safe to continue the flight."
Oh come on...... Who do you think they asked???

[lomapaseo]

You would think something so small to pass through on-board filters would just burn int he can instead of lodging and disturbing the peace inside the FCUs. Must be some pretty tenacious stuff, surely there is other material that can be used as a filtering medium?

The stuff is all sizes and only partially dissolved depending on pressure, temp etc.. A very small amount may get through the last chance filter and afterwards morph into a minute egg with a hard enough shell to jam a valve.

FADECs are not prepared for sticky valves.

It's certainly not everyday stuff.

[JammedStab]

Oh come on...... Who do you think they asked???

According to the report, they asked a maintenance engineer at maintenance Control if it was safe to continue the flight.. So I think that is who they asked.

[Landflap]

First, apologies to all because I have NOT read the report. For some reason, I am unable to axis the link & then when I got into a second link the report looked like 217 pages ! I just need my own thinking cleared up please by those who have read the report. Looks from gleaning other posts that the aircraft wound up with thrust problems at top of climb which lead the crew to investigate and the upshot was one engine stuck at high thrust ( uncontrollable, then) and the other stuck at low thrust. Essentially, a 50% loss of available power. ICAO definition is that this would be a Mayday & divert to the nearest suitable alternate.

I am with the RR engineer on this. Continuing to destination on one engine is not a good decision if suitable en-route alternates are available. For those who don't get it, what if the remaining engine quits ? BOAC does get it, as usual.

I would be very worried about an engine stuck at high thrust and the other at idle. Nearest suitable alternate would be the longest runway available with fabbo weather. If the engine really was "stuck" at high thrust, what consideration was given to the landing. What config ? Shut it down on touch down ? Shut it down just before touch ? And, Lordy Lordy, if it is not your day and a GA is necessary, how are you going to do that ? I would certainly want an obstacle free GA area. Straight ahead to whatever alt you like would be something I would be working on very clearly.

I would be very interested in the influence Base Engineers had on the Commander's decision making.

Tough calls on all and a terriffic discussion on "What would YOU have done" type threads. I offer my thoughts for clarification & possible discussion and re-iterate that I have not read the report. Apologies if I have got anything wrong as a result.

[nitpicker330]

Landflap........mate, come on. I strongly suggest you READ the report. They did not continue on one Engine.......:D

Engage brain before opening mouth. ( or in this case before typing )

[BuzzBox]

As nitpicker said, get real and read the :mad: report.

They had some very minor EPR fluctuations during the climb followed by an ENG 2 CTL SYS FAULT ECAM message and an associated ENG 2 SLOW RESPONSE message shortly after top-of-climb. They contacted the engineers in Hong Kong for advice and checked the engines for control response to thrust lever movements, which they found to be normal. In the absence of any other abnormal indications they decided to continue to Hong Kong. The other problems did not occur until they were on descent into Hong Kong.

[J.O.]

It's one thing to read the report and then post a differing view on what transpired. It's another altogether to post a differing view while admitting that you haven't even looked at the factual information before making your (wrong) conclusions. :ugh:

[johnhb]

From the analysis of the report I don't see that the root cause was actually identified.

It is not clear that the metering valve piston was actually seized. It may has been tight due to the observed deposit of SAP material in the fit clearance so it would be difficult to move it with hand pressure but this does not mean that the torque motor - servovalve should not be capable of moving the stuck piston - if the servo valve was functional. I don't know the exact numbers but with a servo supply pressure difference of 1000 psi and a 2" diameter piston at least a few hundred pounds of operating force should be available to move the piston and maintain some kind of partial metering control.

I think it is likely that control was totally lost because the torque motor - servovalve was plugged and according to the report nothing was done to evaluate condition of this component.

[Sqwak7700]

It's another altogether to post a differing view while admitting that you haven't even looked at the factual information before making your (wrong) conclusions.

Actually, it is more like making up stuff because you are too lazy to do some reading on what actually happened, then blaming the crew as if they actually existed in this made-up alternate reality that exists only in your head.

Some psychologists would label that insane. Such posts should be deleted and referred to a mental professional as they are clearly a cry for help. :O

[Herod]

Let's not get into a slanging match over this. The way I see it, the crew had some relatively minor problems which, in the opinion of themselves and the maintenance team, could be carried to destination. When it all began to turn to worms in a completely unpredictable way, the crew handled the emergency in a very professional manner. Hats off to them, and I would like to think I could have done as well: but thankfully never had to.

[slowjet]

Sq 77 and others of the same hot head brigade ; what an extraordinary knee jerk to Landflap but fairly typical of an antipodean. Hope you chaps are seriously NOT professional pilots because this is the sort of over-reaction we try to avoid on most flight-decks ! Landflap apologised at least twice for not having read the report but was commenting on the posts already offered. Some of these claim to have read the report and still publish opinions based on incorrect understanding. A bit more professionalism in puting people straight required here...............too much to expect from the lnee jerkers ! Shame but only to be expected.

[FANS]

After the recent BA divert to BHX, and then this incident I think we need to pay more attention to engine indications and even if there are consistent but slight EPR fluctuations, we need to question more despite engineering's assurance that it's OK to continue.

That is written with the benefit of hindsight of these two incidents.

[BuzzBox]

Thanks for the lecture on professionalism, slowjet. Here's one for you:

A PROFESSIONAL would take the time to read the report and form a PROFESSIONAL opinion before commenting, rather than making ridiculous statements based on ill-informed rubbish posted on PPRuNE.

[Sqwak7700]

Well put Buzzbox, I guess Slowjet overlooked that slightly major point.

Landflap apologised at least twice for not having read the report but was commenting on the posts already offered

So what you are saying is that as long as I apologize first, I can then say whatever I feel like, even if it is completely made up, and I can't be criticized for it? This is a professional forum, or at least, it is supposed to be. People jumping into the conversation to inject imaginary scenarios that clearly did not occur do not help the discussion. :ugh:

[Landflap]

Ah, good. Some calming down but Sqw77 still sqwaking a bit.Ease up, er, mate, & throw away your ameteur psycholgy books. There's a good chappy. Now, I have read the report. APOLOGIES to all offended. No offense intended.No imaginary scenarios dreamed up, only comment on posts previously made . Questionable but all good Pprune "rumours" and news stuff. Factually, to me, an outstanding job done by these guys. I reserve the right to comment but in all humility, accept the berating rained down on me. The lack of quality in the slap down leaves me bemused and more than a little worried.

[boofta]

A fantastic job by the boys in blue.
ATC getting info from IOC, what a crock of crap.
ATC gives a clearance for a mayday aircraft to use
either runway, then from the transcript " standby
for landing clearance"
A full emergency not declared by ATC and standby
for a landing clearance for a MAYDAY aircraft.
The worst aspects of an over-regulated rule driven
nonsensical ATC circus, whatever happened to common sense.
I wonder if the controllers would have given a more general
"track/speed as required cleared to land wherever you like"
if their relatives were on board?
Stand by for landing clearance my arse.
Idiots

[DessertRat]

MSD-AGIN and JPJP,

So you disapprove of the PF's use of autopilot at 1100' on departure.

Flown in Indonesia much? The most erratic ATC and RT in the world, combined with ever present TS and CB activity.

I think both pilots actively monitoring TCAS, traffic, wx radar etc in this case would be a much better option than having one head-in slavishly following the FD.

We weren't there. They were.

The PF obviously does not need more time 'hands on'. Or your condescension.

[bekolblockage]

I haven't had a chance to read the report yet but can tell you I witnessed the event play out on radar.

While not downplaying the issues of upgrading from local standby to full emergency in the latter stages and the usefulness of a landing clearance under the circumstances, I know for a fact that the Captain tracked down and personally thanked the Approach controller who provided an exemplary service in positioning the aircraft to become visual immediately off the western end of Lantau and in a position where a landing was basically assured.

I think the crew will confirm for you that "tracking as required" in IMC (which they were, or at least had little visual reference except for the Sokoes) may have resulted in a less than favourable outcome.

Nice to see you think so highly of us. You probably get a mention in our conversations about arse and elbow as well.

[slowjet]

Only just managed to read the report. Gosh, what a splendid job. Appears to me that they flew the book. This happened in 2010. Any info on how the crew were treated by CX and where they are now. Masters in their class.

[Clandestino]

I'm glad that there were no plot twists introduced since interim got out and the final tale remained to be one of excellent airmanship. This crew should be honoured just as Shornstheimer/Tomkins, Genotte/Michielsen/Rofail, and Sullenberger/Skiles are.

Can we PLEASE think again on the criteria for chucking the pax down the slides and into hospital?!?!It's simple: if it's more dangerous inside the aeroplane than outside; evacuate. Determination is the hard part. I'd say with extreme energy landing and confirming with rescue leader there indeed was fire around wheels, I'd just concur with CAD that the decision to evacuate was reasonable and suggest reading the CVR transcript as an example of stellar CRM.

Why didn't he shut down that one stuck at hi power?
Seems like a no brainer, duh! While report makes it clear why they made good decision not to shut it down, I'd agree it seems like no-brainers got abundant around here.

I see the first maintenance engineer gave advice and based on that the crew made the decision to continue.Correct advice as there was only EPR fluctuation at the time and that absolutely did not unequivocally point towards the trouble that was going to occur.

By the time ME2 was involved VHHH was clearly the only possibility. Yes, but by the time ME2 was involved engines were still operating, there was till no sign that they would become uncontrollable.

Much trust in one engine flying. They were not flying on one engine, except briefly when trying to coax No2 to work above idle. Granted there was not much thrust from right side but at least

In hindsight the decision to continue to destination proved to be problematic. It was appropriate. There were no indications of how serious the situation would turn out to be until very well into descent.

In hindsight the decision to continue to destination proved to be problematic. Maybe I'm being oversensitive living just a stone's throw from Kegworth. Good you mentioned it as this incident is the exact opposite of Kegworth; here crew kept both engines running and while uncontrollable, they did provided them with means of reaching the runway. Kegworth was case of too-much-too-soon.

A/P on at 1144'. Daytime departure. So what?

The point of the Magenta Line syndrome isn't the fact that familiarity with automation is inherently dangerous.Exactly. There is line of ignorant opinion around here that magenta's children are folks lacking manual flying skills and that it can be cured by flying raw data manual departures and arrivals. The children of magenta are actually folks who were unable to remain calm, focused and reasonable under unusual circumstances (often of their own making) so: turned away 90° off course and hit the mountain, tried to climb aeroplane where it just wouldn't go, got so excited about gear problems they wasted all of their fuel preparing to land, took off with both IRS toppled, reextended the gear on 737 after failure just after liftoff as it were Seneca and they planned to land ahead etc. Some of them might have been lousy stick and rudder pilots, some were proven to be excellent but they perished anyway.
Widebody captain at 35? That's a fairy tale over here.... If this didn't prove him commandworthy, nothing will. It's just the matter of matching the seats to bodies. It differs from location to location and also from one temporal period to another.

What I meant to say was that there hadn't been much comment in this thread. Given the quality of the discussion we had so far, I wouldn't count it as a bad thing.

Oh come on...... Who do you think they asked??? Their maintenance. You know, those folks who can follow your flight parameters in real time nowadays and your aeroplane's health is their sole concern, they don't have to deal with aviation, navigation and comunication.

Looks from gleaning other posts that the aircraft wound up with thrust problems at top of climbIt does and bears no semblance to reality.

And, Lordy Lordy, if it is not your day and a GA is necessary, how are you going to do that ?Just like in a glider. Concentrates one's mind wonderfully.

From the analysis of the report I don't see that the root cause was actually identified.

(...)

I think it is likely that control was totally lost because the torque motor - servovalve was plugged and according to the report nothing was done to evaluate condition of this component.
Are you seriously suggesting a) there could be two one-in-a-couple-million FH events occurring simultaneously with contamination or b) actual mechanism of SAP affecting the FMVs is somehow of concern because we need to make them SAP resistant?

After the recent BA divert to BHX, and then this incident I think we need to pay more attention to engine indications and even if there are consistent but slight EPR fluctuations, we need to question more despite engineering's assurance that it's OK to continue. How do you propose to do that if no new probes and indicators are installed?

Appears to me that they flew the book.They absolutely did not. There was no book and they broke quite a few procedures and limitations so everyone onboard could be blessed with continued existence.

[bekolblockage]

Having just read the report to refresh my memory, your outrage at the handling by the Approach controller is exceeded only by your ignorance.

The Approach controller realized the crew were operating under extreme workload conditions and rightly refrained from issuing a frequency change to the Tower frequency. Instead the Approach controller (located inside the enclosed radar centre) selected the intercom line to the North runway Air Movement Controller and relayed the landing clearance on her behalf, as he was not in a position to determine 100% that the runway was clear himself.
Although the preceding landing was initially well ahead when CPA780 was cleared for a visual approach, the rate of closure was extreme with the ground speed at almost 240kts and as it turned out the preceding aircraft was only just clear of the runway when 780 approached the threshold.

[JammedStab]

Correct advice as there was only EPR fluctuation at the time and that absolutely did not unequivocally point towards the trouble that was going to occur.


Quite a wonderful job done to get everyone down as they did.

As can be seen, fuel contamination can affect both engines as seen by the EPR fluctuations on both engines. Is there anything else that could cause unusual indications on more than one engine. Maybe icing conditions where the anti-ice was not applied pops into mind. Volcanic ash. Anything else to consider in such a scenario.

[HDRW]

... As can be seen, fuel contamination can affect both engines as seen by the EPR fluctuations on both engines. Is there anything else that could cause unusual indications on more than one engine. Maybe icing conditions where the anti-ice was not applied pops into mind. Volcanic ash. Anything else to consider in such a scenario.

Large flock of birds?

[lomapaseo]

As can be seen, fuel contamination can affect both engines as seen by the EPR fluctuations on both engines. Is there anything else that could cause unusual indications on more than one engine. Maybe icing conditions where the anti-ice was not applied pops into mind. Volcanic ash. Anything else to consider in such a scenario.

Like you said ice-crystals at altitude or volcanic ash probe blockage.

All this is covered in the FCOMs.

If the fuel SAP problems become more frequent there is always the possibility that somebody could update the manuals. I'm not very keen on the crew trying to decipher it, but the FADECs probably could.

The problem, to me, is that there is not much the crew can do about it other than what these guys did.

What happens in the air is not the problem, it's what happens when you try and land. I would like to have the equipment standing by on a long runway being prepared for an excursion.

[boofta]

bekolblockage
Now even more outraged that at a 240 knot approach speed the fool
says standby for anything, get a grip, its not about checking with
any other section of ATC. Its a dire emergency, from the mayday call
its no frequency changes, do whatever to save the day.
Are you guys actually thinking your part of the solution with your
standby I'm not sure proceedures.

[ExRR]

Is it not particularly unusual to have irregularities showing on more than one engine?

and

Is it not particularly unusual to have indeterminate irregularities (even if minor) showing on all engines?

Just basic questions that I see from my perspective - no vitriol necessary.

You guys might fly every day with a number of issues over which a decision is made to continue and monitor. On the other hand I see press reports of flights returning to base because a warning light was showing that on examination only proved to be a faulty sensor.

[tdracer]

All current FADEC engine control systems are dual channel, fault tolerant systems (the exception being they all use a single fuel metering valve, so if it seizes it's game over). Single faults are typically no more than an annoyance - on Boeing airplanes the flight crew is not even notified of FADEC faults in flight (significant or serious faults set Status messages, but there are no procedures that tell the pilots to check Status - it's intended for maintenance use). Seeing a minor EPR oscillation and ECAM fault on one engine wouldn't be expected to be a significant concern. The worsening of the EPR oscillation and the problems with the second engine didn't occur until late in the flight - at which point a diversion was probably pointless since the destination was nearby.

Fuel contamination is typically indicated by fuel filter bypass - procedures for gross fuel contamination are based on getting fuel filter bypass on multiple engines. To the best of my knowledge, this is the first time there has been a significant event due to gross fuel contamination that didn't have an associated fuel filter bypass indication.

[slowjet]

CLANDESTINO : Cripes ! Careful ! You will have the likes of Sqwak 7700 self imploding into a frenzy for coming in here, with professional pilots, and commenting on, er, comments ! As you are Head of Pprune Air Accident Investigations Dept & we all value your' epic hindsight & one line comments, answer this pleeze ; What part of not flying the book are you referring to ? Good diagnostic efforts by the Commander, great CRM (even though I hate CRM), excellent Command decisions, excellent situational awarenes, excellent managerial skills & then faced with a possible single engine scenario, then; ooops, no engine scenario, then; oops, SE but stuck at high thrust...................oh, the list goes on. But do tell us why the guy "Absolutely did not fly the book" ?

[CYRILJGROOVE]

These young guys delivered when they had to, the Captain was not long in the left hand seat and a great result was achieved. No loss off life and no hull loss.

The thing that strikes me most is that 99% of the staff in Cathay don't know his name and he and the FO do not seek fame and adulation. A far cry from other tossers who got an opportunity to strut their stuff and sought out crass television interviews by the dozen, wrote books and sought individual glory without giving credit to other crew members....and even did not actually pass the line check he was on....Warren comes to mind, and apologies to the hundreds of good pilots in that mob. Even Sully soaked it up a bit too much IMHO

Whilst internally, in CX the Chairman of CX did show class and has spent some time with our young man who performed on the day and to Capt XX and FO XX well done you have the universal respect of 100% of your co workers you do deserve an award for distinguished flying skills.

[Herod]

you do deserve an award for distinguished flying skills.

I second that. How about 1% of the hull value?

[CodyBlade]

''1. When it became obvious that they had both engines indicating 'stall', the commander traded excess airspeed for altitude. A small detail, but an action that shows excellent situational awareness.'' [A la Cessna 172 basics]

In times of extreme stress we revert to early training, that's why having a great instructor is crucial who beds down SA/Airmanship is paid-up insurance.

[Capn Bloggs]

The children of magenta are actually folks who were unable to remain calm, focused and reasonable under unusual circumstances (often of their own making) so: turned away 90° off course and hit the mountain, tried to climb aeroplane where it just wouldn't go, got so excited about gear problems they wasted all of their fuel preparing to land, took off with both IRS toppled, reextended the gear on 737 after failure just after liftoff as it were Seneca and they planned to land ahead etc.
None of which have anything to do with The Magenta (apart from possibly the first). :cool:

[johnhb]

Re; Clandestino,

"Are you seriously suggesting a) there could be two one-in-a-couple-million FH events occurring simultaneously with contamination or b) actual mechanism of SAP affecting the FMVs is somehow of concern because we need to make them SAP resistant?"


The contamination test (Ref. pg. 212 of report) requires that the system operate with a mix of particles 0 to 1500 micron size. This failure was caused by contaminant 25 micron nominal size, albeit substantially different from the quartz, road dust, etc. of the test.

When the FMUs were taken apart the report does not show which components were actually non functional. Thumb pressure is not adequate to determine if the metering sleeve was really stuck as a much larger force is available to operate it if the metering valve servo control is working.

I ask about the torque motor - servovalves because the report says nothing about their condition. Since with low operating force and small flow passages they are likely to be more sensitive to effect of contamination than the other FMU components.

[JPJP]

MSD-AGIN and JPJP,

So you disapprove of the PF's use of autopilot at 1100' on departure.

Flown in Indonesia much? The most erratic ATC and RT in the world, combined with ever present TS and CB activity.

I think both pilots actively monitoring TCAS, traffic, wx radar etc in this case would be a much better option than having one head-in slavishly following the FD.

We weren't there. They were.

The PF obviously does not need more time 'hands on'. Or your condescension.


No, I don't disapprove. As I said in my first post, I thought they did an excellent job. Perhaps you should read it again. My second post was tongue in cheek. Hence the funny little face after it.

What I do disapprove of, is your apparent inability to read. If English isn't your first language or Indonesia is messing with your head, I apologize.

[Methersgate]

"Esse quam videri".

One of the best companies in the world, in my day, and clearly it still is.

[Crabman]

In reading the analysis section of the report, I notice that different adjectives (or sometimes adverbs) are used to describe the actions of various parties during the evolution of the incident. Sometimes an action is described as "appropriate" (or done "appropriately"). Sometimes the adjectives "reasonable" or "understandable" are used.

My question is, in investigative jargon are there qualitative differences among the different adjectives? I.e., is an "appropriate" action deemed better than a "reasonable" action? Is a "reasonable" action better than an "understandable" action? Or is the author (or translator) of the report just varying his words?

[DingerX]

Well, to do that, you'll need to do some textual analysis. but generally, style is not an issue with these things.
I didn't have a problem reading it, so what I'd expect to be the case would be:

Appropriate: the proper action for external reality* and the SOPs envisioned for it (*as argued for by the report).
Reasonable: an action that, giving the data available to the agent at that moment, would be correspond to a normative model for appropriate actions.
Understandable: an action that, while contrary to the normative model for appropriate actions, falls within the range of deviation considered normal for human actions.

Make sense?
Okay, how about:
Appropriate: the right thing to do.
Reasonable: should have been the right thing to do (and maybe was).
Understandable: seemed like the right thing to do.

[lomapaseo]

My read of the text, is that some items are still open to be addressed in future recommendation without prejudice to any of the parties.

[Machinbird]

There is no doubt that this crew did a fabulous job. They were thinking pretty far ahead considering the number of surprises that the aircraft threw at them.

In my reading of the accident report, there is one thing that stands out to my tactical pilot eye, the use of the speed brakes.
Since I've never flown the type, I figured I'd ask some of you who have experience in the type.


From the accident report:
m. At 0540 hrs, Hong Kong Approach cleared CPA780 for a visual approach for Runway 07L. Flight crew deployed the speedbrakes when the aircraft was at 5,216 ft AMSL descending with a CAS of 234 kt at around 8 nm from VHHH. Flight crew selected landing gear down shortly afterwards.

n. The Commander aimed to fly the aircraft at a CAS as close as possible to the Minimum Selectable Speed (VLS), which was 158 kt at that time. The aircraft went through the runway extended centreline and recaptured the centreline from the north in order to manage altitude and airspeed. Landing checklist was actioned. At around 0541 hrs, with the Maximum Allowable Speed (Vmax) at 240 kt and actual CAS at 244 kt, an overspeed warning was generated by the onboard system. A short while later Hong Kong Approach cleared CPA780 to land on Runway 07L and advised that the current surface wind was 150 degrees at 13 kt. Flight crew stowed the speedbrakes when the aircraft was at 984 ft AMSL and armed the ground spoilers at 816 ft AMSL.
I can understand the pilot's wish to keep the aircraft in a configuration that he had experienced before, thus retracting the speed brakes and arming the ground spoilers, but in this case, given an aproach ~95 knots faster than the usual, with the Flaps 1 selection aerodynamically limited, was it necessary to retract the speed brakes?

If the speed brakes had remain deployed, is it likely that the aircraft would not have had such an ungainly bounce which delayed activation of the spoilers and commencement of braking (as well as overstressing the nose and left main landing gear and scraping the #1 pod)?

I am not asking these questions with any intent to be critical of this crew, who handled a difficult situation with great professionalism. I am asking to see if there is anything else from this accident that might be learned, and to at least answer my own curiosity.

Prior to the date of this incident, had anyone received training in a similar type of dual engine problem scenario? It seems to me that a training scenario like this would likely be considered low probability and thus not given training emphasis.

[nitpicker330]

What he did seemed to work out just fine.

[BOAC]

No type experience and extreme reluctance to 'unpick' an excellent piece of flying from the benefit of my armchair in a situation I would have dreaded to find myself. However, since you have asked, my take:-

Yes, speedbrake would have helped dissipate the excess energy

I suspect it was 'stowed' for 2 reasons:-

1) We do not practice flaring and touching down with them deployed, so that would be an 'unknown', and the potential sink rates, possible change in pitch response and the buffet would have been dramatic and possibly disconcerting

2) It is driven into us that speedbrake must not be deployed below 1000', and with everything else they were handling at that time, it could have been an 'automatic' understandable reaction.

[Hand Solo]

If the 330 is like the 320 then you can't arm the ground spoilers whilst keeping the speed brakes deployed. It's the same lever but in two different positions.

[J.O.]

Landing with speed brakes deployed is a very bad idea and I believe it's also prohibited in the AFM.

[DessertRat]

JPJP - you said:

"A/P on at 1144'. Daytime departure.
Ha

Yeah. I noticed that. Perhaps the FO had been hand flying the aircraft so much he decided that some automation familiarization was in order ...."


JPJP, you were being condescending. Nice try wriggling out of it though.

[JammedStab]

I know some aircraft types have had tailstrikes when accidentally landing with speedbrakes deployed. However, if this situation were to happen on a shorter runway, it might be better than an overrun.

[ZAGORFLY]

Dont they are hinibited to deploy if you have power setting above idle?
Then my question is why engine one was not takent out the line by arming and eventually discharging the fire extinguish system? Asymmetric reverse thrust is recommended in similar events?
Good job crew anyway . A good happy ending story

[J.O.]

That engine was still supplying hydraulic power to the green system, so why on earth would you shut it down in a situation where control of the aircraft was already compromised by "stuck" thrust on # 2.