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.

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.

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?

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

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.

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.

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.

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 )

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.

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:

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.

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

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.

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.

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.

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.

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

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:

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.

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

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.

boofta
 

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.

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.

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.

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.

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.

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.

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

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

It was appropriate. There were no indications of how serious the situation would turn out to be until very well into descent.

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.

So what?

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.
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.

Given the quality of the discussion we had so far, I wouldn't count it as a bad thing.

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.

It does and bears no semblance to reality.

Just like in a glider. Concentrates one's mind wonderfully.

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?

How do you propose to do that if no new probes and indicators are installed?

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.

Boofta
 

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.

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.

Large flock of birds?

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.

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.

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.

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.

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" ?

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.

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

''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.

None of which have anything to do with The Magenta (apart from possibly the first). :cool:

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.

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.

Post 72
 

"Esse quam videri".

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

Question
 

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?

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.