Final report on CX780 accident published

[bekolblockage]

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.

[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.

Originally Posted by BARKINGMAD

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.

Originally Posted by Killaroo

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.

Originally Posted by ExRR

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.

Originally Posted by ExRR

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.

Originally Posted by ExRR

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

Originally Posted by ExRR

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.

Originally Posted by ExRR

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.

Originally Posted by misd-again

A/P on at 1144'. Daytime departure.

So what?

Originally Posted by JPJP

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.

Originally Posted by Huck

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.

Originally Posted by avturboy

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.

Originally Posted by crwknut roll

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.

Originally Posted by Landflap

Looks from gleaning other posts that the aircraft wound up with thrust problems at top of climb

It does and bears no semblance to reality.

Originally Posted by Landflap

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.

Originally Posted by johnb

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?

Originally Posted by 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.

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

Originally Posted by slowjet

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]

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.

[JammedStab]

Originally Posted by Clandestino

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]

Originally Posted by JammedStab

... 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]

Originally Posted by ClandoRant

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).

[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]

Post 72

"Esse quam videri".

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

[Crabman]

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?

[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.