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-   -   ETOPS and the ETP (https://www.pprune.org/australia-new-zealand-pacific/527390-etops-etp.html)

vincenzo vaughnetto 9th Nov 2013 01:29

ETOPS and the ETP
 
Fact or fiction?
Within the last month, an Australian registered Airbus 330, en route from Australia to Honolulu, had an engine roll back to idle prior to the CP for Honolulu and the Marshall Islands ETOPS segment, and continued on to destination.
The flight was completed safely. That is the most important point.
However, what caused the problem and what do we consider to be a critical system failure, if not an engine rolling back to idle?
There are many considerations. If the event occurred, can we have a fair and balanced discussion of all options?

AutoPilotA 9th Nov 2013 11:30

Hmmm

That would be either Jet* or QF ? Not sure if QF ever use the 330 on that route ?

unseen 9th Nov 2013 13:28

ETOPS and the ETP
 
What do you think they should have done and why?

Are you suggesting they should have diverted to the Marshall Islands because they were prior to the CP?

AutoPilotA 9th Nov 2013 13:47

Would be a brave man (or woman) to take take 300 odd pax to a little island in the middle of the ocean !..... in the dark !.... I reckon..... unless there was no other option that could be justified !

Wizofoz 9th Nov 2013 16:23

I'm not familiar with the route, but know a little about ETOPS.

Just because an airfield has been nominated as the ETOPS suitable in order to comply with ETOPS, this does not mean the aircraft must divert to that particular aerodrome in the event of a failure.

"Land at nearest suitable airport" (or AB equivalent) still applies- as does the decision making in determining what is and isn't the most suitable at that moment.

If it was clearly safer and not much further to continue, that is absolutely justifiable.

waren9 9th Nov 2013 16:25

etp and cp have different definitions.

suggest you reword your post to get the discussion you are fishing for

haughtney1 9th Nov 2013 17:13

Without knowing what is specifically contained within the relevant QRH et al, it is hard to do anything other than speculate.
A rollback as you suggest, would not, I assume, mandate diverting to the nearest piece of tarmac. You still have all the relevant services associated with the engine, so at least initially from a generic standpoint you have a little more time up your sleeve to think.
Its far more cut and dry when for example you have to secure the engine due to indications of further damage, no oil pressure/quantity etc etc.
But lets assume its just a rollback, what are the other engine indications showing? have you had any external confirmation/information regarding further damage to the engine airframe? Is the other engine performing as expected? Did you dispatch with an APU? (you can fly ETOP's without one)
Whats the weather like at your likely diversion airfields? navaid status etc etc etc, the list goes on and on.
Only then, with a decent amount of situational awareness can you realistically come up with a reasonable set of options, one of which might be continue to destination:E

compressor stall 9th Nov 2013 20:49

Out of interest - where does the company (which ever one it is) define the EEP on that route....

(I'm not trying to second guess the crews actions, but the unique Australianism of the rules' interpretation is worth discussing).

blueloo 9th Nov 2013 21:21

Would not the critical point re engine failure or rollback (other than severe damage considerations) be primarily concerned with drift down to E/O cruise altitude and being able to make the nearest suitable or adequate with the appropriate reserves.

If sufficient fuel is on board to make destination (plus required reserves) and assuming they have not gone past the nearest suitable then there probably shouldn't be an issue. (I think the actual requirement is that it can't be beyond the maximum diversion time or distance....)

Additional fuel ordered over flight plan fuel will in some cases change your ETOPS /DPA/CPE data. (Also depends on airport availability on certain routes)... It's just that many do not recalculate it.

Airmanship may ultimately dictate a different course of action.

gordonfvckingramsay 10th Nov 2013 00:16

From CAO 20.6, "Continuation with 1 or more engines inop":

3.2 The pilot in command of a multi-engine aircraft in which 1 engine fails or its rotation

is stopped, may proceed to an aerodrome of his or her selection instead of the nearest

suitable aerodrome if, upon consideration of all relevant factors, he or she deems such

action to be safe and operationally acceptable. Relevant factors must include the

following:

(a) nature of the malfunctioning and the possible mechanical difficulties which may
be encountered if the flight is continued;

(aa) the nature and extent of any city, town or populous area over which the aircraft is
likely to fly;

(b) availability of the inoperative engine to be used;

(c) altitude, aircraft weight, and usable fuel at the time of engine stoppage;

(d) distance to be flown coupled with the performance availability should another
engine fail;

(e) relative characteristics of aerodromes available for landing;

(f) weather conditions en route and at possible landing points;

(g) air traffic congestion;

(h) type of terrain, including whether the flight is likely to be over water;

(i) familiarity of the pilot with the aerodrome to be used.


Most airlines employ some sort of decision making model. I assume the crew took all of these items into account and made the call based on that.


1a sound asleep 10th Nov 2013 01:14

MAJ has no ATIS only a unicom. No idea how long it takes to wake somebody up there. I think I would continue to HNL assuming everything else seems ok

PPR FOR NGT LNDG BY ARPT MGR/DIST ADMIR, EXCP EMERG, RPRT WI 48 HOURS.

200' TWR LCTD 07-06-15N & 171-22-22E OBSTN LGTD.

PARTIALLY PAVED WATER CATCHMENT AREA BOTH SIDES OF RWY WITH VENT PIPES 1' ABOVE SFC.

swh 10th Nov 2013 01:32


Originally Posted by gordonfvckingramsay
3.2 The pilot in command of a multi-engine aircraft in which 1 engine fails or its rotation is stopped

Excuse me if I am pointing out the obvious, I would think an engine operating at idle has not failed or stopped rotating. Otherwise I have multiple engine failures every flight.

compressor stall 10th Nov 2013 01:43


MAJ has no ATIS only a unicom. No idea how long it takes to wake somebody up there.
IF - and I repeat IF - MAJ was one of their nominated EDTO alternates, then according to the regs they would be ready in 30 mins.

(That, however, still doesn't mean you must head there).

FYSTI 10th Nov 2013 02:59

SWH beat me to it.

which 1 engine fails or its rotation is stopped
This is the key clause, in the case of roll-back, did either of those conditions occur? A malfunction yes, a failure or its rotation stopped, hmm? Airbus go to great lengths in their FCOM bulletin to give guidance for the avoidance of unnecessary in-flight shutdowns. More info directly from Airbus.

Splitting hairs, yes, but there are subtle differences between the regulations & the manufactures guidance creating a large grey area in the case of reduced thrust operation - which is Airbus policy unless a checklist directs the engine to be shutdown.

gordonfvckingramsay 10th Nov 2013 06:49

Was thrust restored or available? If not, it is little more than an APU.

Either way, CAO 20.6 allows the crew to make a decision to continue to a suitable alternate based on all those criteria and not just the closest one. That was my point :ok:

The Green Goblin 10th Nov 2013 06:56

Sounds like another faulty thronomeister.

Unless you were on the FD, then the decision making is not your business.

Capt Fathom 10th Nov 2013 08:11


Unless you were on the FD, then the decision making is not your business.
It is of interest if you happen to be a passenger on that flight!

aveng 10th Nov 2013 11:03

How long ago was this? Because QF fleet have been modified to prevent this. The dedicated generator is used to supply power to the engine computer when running above 15%, since the mod - aircraft power can supply the EEC if dedicated gen supply fails.

clark y 10th Nov 2013 19:25

Failed/rolled back what's the difference? Splitting hairs. As Gordon said it's little more than an APU. Your basically in a 200 ton single engine aircraft in the middle of the Pacific. As for the incident in question I was not on the flight deck so will not comment on the decision making process.
Manufacturers and airlines do not like inflight shutdowns because it may affect ETOPs/ETOPs approvals and makes the media. I'd like to know what caused the roll back and how to rectify it. Shame you can't have direct law on the engines like flight controls.

The Green Goblin 11th Nov 2013 01:17


Quote:
Unless you were on the FD, then the decision making is not your business.
It is of interest if you happen to be a passenger on that flight!
That's why the crew are paid the big bucks :hmm:

To keep the Trents and Shazzas of this world oblivious. After all, modern aircraft fly and fix themselves. We are glorified bus drivers who just sit there, push buttons and drink coffee.

:ok:


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