View Full Version : Air Transat thread (cont)

Ranger One
2nd Sep 2001, 07:14
We reached the 100 mark... we left off the old thread here:

Old thread, final page (http://www.pprune.org/cgibin/ultimatebb.cgi?ubb=get_topic&f=1&t=015188&p=7)

Here's a thought, provoked by Airboeings post which mentioned the enormous proportions fuel leaks can assume: this wasn't a catastrophic situation, the crew had time to analyse the problem and gather data. If you had been on that flight deck, do you think it would have occured to you to call the cabin and ascertain whether there was a *visible* leak, and whether your actions had ameliorated it?

This, and the Concorde thread, have been some of the best I've seen lately - some very thoughtful contributions. I'll be very interested to hear the final verdict on this one, it definitely falls into the 'can't happen... but it did' category.


[ 02 September 2001: Message edited by: Ranger One ]

Flight Safety
2nd Sep 2001, 09:12
I find myself having to agree with the summary of events that Skybloke gave on page 6 of the previous thread. The events can be summarized in the phrase "they left the #2 engine running", which Skybloke used more than once in his summary. Clearly this was not good fuel management once they determined they had a fuel leak, and this explains the massive loss of fuel.

2nd Sep 2001, 09:18
One thing is for SURE, we can all learn from this incident, and as a bonus, no injuries or bent equipment.

2nd Sep 2001, 11:31
Ranger One....

I Think it would be pretty difficult to see a fuel leak at night coming from an engine.I'm sure it may also spark a bit of unrest with the pax with you poking your nose at the window.

With regards to the de-pressurization. I recall the pax stating that the masks dropped. Is there no help from the RAT for this system?

2nd Sep 2001, 12:13
Regarding pressurisation problems; The outflow valve/s would have driven closed under stanby electical power (Rat/battery)and the cabin leakage rate would then determine how long before cabin altitude equalled aircraft altitude. Depending upon the condition of door seals etc. it could take some time. It (cabin alt) obviously reached the mask trigger point (approx 13000ft ??on Airbus) but the leakage rate is probably a lot less than most might think, maybe 700 ft/min for example.

This is not like an explosive decompression and can be equated to the volcanic ash scenarios in Indonesia (BA747) and Alaska (KLM 747) where all 4 engines flamed out and the crews were faced with conflicting requirements of best glide speed versus high airspeed for windmill relight of engines and cabin pressuisation.

2nd Sep 2001, 18:04
AIRBOEING's statement that the probable positions of the fuel shutoff valves: null the LP by the wing spar (generally placed well away from the engine so that it can do some good in case of fire),
null the HP with the engine supports the pilots' action to restore/continue the crossfeed -- fine as long as the LP shutoff does not fail and how do you catch that in time?
So, we may have either: null two component failures -- pipe and LP valve (with invidious implications for maintenance)
pipe rupture above LP valve (less likely, but if so, a design shortcoming).
In either nasty case, a crossfeed valve is your last line of defense, as long as there's enough accessible fuel for the remaining engine(s) to get to an airport.

2nd Sep 2001, 18:39
Gulfer - I did say in my post that the 330 normaly does better than the 3nm/1,000', but obvoiusly the NORMAL slope would be degraded by windmilling engines and no residual thrust (though you would probably get this back by comming down at a more efficient speed)
CaptainX - sorry, but I would rather have enough fuel on ONE engine than insufficient on two, fine, start of that way, but then monitoring the situation should tell you it is NOT working and time to shut off the US side.
N.B. anyone tried dead stick in the sim?
not tried it yet, but I would probably aim for slightly high at 5 miles (say 1,600 - 1700') and clean, then drop everything and accept what I got on landing - probably fast, but safer that way than short and slow.

2nd Sep 2001, 21:13
Wouldn't the situation been a great deal easier if aircraft were equipped with a FF meter on the engine and another in the fuel line within the wing structure.

I am left with a feeling that the overcomplicated automatic fuel transferring on the A330 has contributed to any confusion that the crew may have had establishing whether they had an engine fuel leak or a wing fuel leak.

Nothing these days seems as simple as the checklist suggests, I suspect because the checklist was drawn up with both eyes on the product liability laws.

After every incident like this I question "how well would I do in that situation?" I have yet to find a situation where I know that I would have done any better and incidents like Soux City fill me with admiration for the guys involved.

No doubt the experts will tell us how to do it better; with the benefit of 20/20 hindsight.

2nd Sep 2001, 21:21
1.AirTransat employes convicted drug smugglers as captains??

2. Did the captain try and isolate the fuel leak or not (crossfeed off)?? Yes or No. There appears to have been plenty of time to "fly the airplane, analyze the situation, and take appropriate action."

This whole episode smells, and it's not getting any better as more facts get known.

What kind of airline is AirTransat???

2nd Sep 2001, 21:51
all right, my turn now :rolleyes:

"great job", "congratulations to all", "well done", etc????? Come on guys, wake up and remove your shades :cool:

It looks to me that this once more a case where pilots have endangered a flight and then saved it :o Call'em heroes if you want, but don't forget one thing, pilots are (still) here to save the day and not to make the situation worse. The same was true of the AC story. Those deadstick landings were good (and extremely lucky ;) ), but guess who first placed the aircraft in this situation:

- Air Transat, rumor has it of a fuel leak on one side, all the fuel dumped overboard thru the xfeed valve, great... :(
- Air Canada, aircraft refuelled with liters, indications in pounds and pilots not knowing how much they have... :(
- Aero Lloyd, gear down flight, fuel consumption relying only on the FMS (who cares about the fuel gages anyway?)... :(

Understand that those lines are not written to attack colleagues, but more to the point, to point out how quickly a highly trained group of professionals can be mislead by the circumstances, stress or just fatigue :eek:

Capt PPRuNe
2nd Sep 2001, 21:52
I believe the A330 arrived overhead the airfield at about 15,000'.

As this is a technical discussion I am moving this thread to the Tech Log forum.