SQ makes emergency landing in Azerbaijan

[samh004]

Re: SQ's GYD A380 incident

What happens if you are flying in an area with 20,000 miles height restriction and you lose pressure?

You'd be in space... so you'd be a bit buggered!

 

[jb747]

Re: SQ's GYD A380 incident

These threads are all about questions and answers as well as discussion and speculation, of which you seem to be doing a fair bit yourself.

I've got no problem per se with speculation. But, when it's not actually based upon anything, then there seems little value. Whilst I'm not a fan of SQ, I see nothing to make me think they wouldn't have properly looked at the issue whilst on the ground.

Door seals occasionally have problems. I've never heard of one progressing beyond the nuisance noise stage. This door shows both external and internal damage. It's an event that is, at the very least, novel.

 

[jb747]

Re: SQ's GYD A380 incident

Thanks again. So that sounds to me like you might get a 'statement' from maintenance immediately pre departure that all known faulted items "comply / fixed / per manufacturer's standards" and you are entitled to rely on that?

The maintenance log is still paper. The A380 came with an electronic version, but it was terrible, and sensibly abandoned.

The book consists of a number of sections, but the relevant ones here are the maintenance chits, and the hold items. Any item we enter goes onto a chit, and the work done to clear the item is added by engineering. A copy of any of this stays with the aircraft, so that we can look back at what has been entered and cleared over the last few flights.

The pilots don't 'reply'. We can reject an item that the engineers have moved to the hold. That would normally be done if it either had operational implications that we couldn't comply with, or if you felt that the collective set of holds was becoming unmanageable. I've rejected them outright a few times, but it's quite rare. Our aircraft are generally quite clean, normally with a small number of holds.

In this case I expect the engineers would have inspected, cleaned and possibly reseated the seals. That should fix 99.9% of their problems.

 

[jb747]

Re: SQ's GYD A380 incident

What happens if you are flying in an area with 20,000 miles height restriction and you lose pressure?

I'll assume you really mean a little lower than that.

If the safely height is 20,000 feet, and you depressurise, then that's as low as you can go. You sit up there until you reach a point at which you can get lower. The route must be planned so that you'll reach these lower levels within the limits of your passenger oxygen. That has the effect of limiting the aircraft that use oxygen generators, as they normally provide just enough for a quick descent, plus a few minutes (10-20).

The A380 and the 747 have a gaseous oxygen system...which means that they have enough to enable the pax to remain on oxygen for some hours (3 hours at 14,000 ft is one standard).

You don't stay at altitude for any time more than necessary though. Passengers aren't breathing via coughpit masks....they are very limited in their abilities.

 

[anat0l]

Re: SQ's GYD A380 incident

The A380 and the 747 have a gaseous oxygen system...which means that they have enough to enable the pax to remain on oxygen for some hours (3 hours at 14,000 ft is one standard).

You don't stay at altitude for any time more than necessary though. Passengers aren't breathing via coughpit masks....they are very limited in their abilities.

Probably doesn't help when a few (or a few more) of them are hyperventilating thinking they are going to die!

 

[ermen]

Re: SQ's GYD A380 incident

I'll assume you really mean a little lower than that.

If the safely height is 20,000 feet, and you depressurise, then that's as low as you can go. You sit up there until you reach a point at which you can get lower. The route must be planned so that you'll reach these lower levels within the limits of your passenger oxygen. That has the effect of limiting the aircraft that use oxygen generators, as they normally provide just enough for a quick descent, plus a few minutes (10-20).

The A380 and the 747 have a gaseous oxygen system...which means that they have enough to enable the pax to remain on oxygen for some hours (3 hours at 14,000 ft is one standard).

You don't stay at altitude for any time more than necessary though. Passengers aren't breathing via coughpit masks....they are very limited in their abilities.

Ah yes - meant to say 20,000 feet.
Can't you descent to 10,000 feet and do VFR?

 

[ermen]

As an arm chair commentator - just looking at this map, presumably the aircraft was north of Afghanistan hence the decision to go to Baku instead of Dubai?

 

[markis10]

Re: SQ's GYD A380 incident

Ah yes - meant to say 20,000 feet.
Can't you descent to 10,000 feet and do VFR?

Not when there are a stack of mountains, the average altitude of the Hindu Kush is close to 15000ft.

 

[lc_461]

Re: SQ's GYD A380 incident

In regards to diversions, many airlines have agreements with ground handlers or other airlines at airports along their flight routes in case of emergency. An example would be Scoot would have a diversion agreement in place at BNE if unable to land at OOL. It probably also has others along the flight route (maybe DRW?) where it could land in case of a technical or medical emergency.

These diversion ports may not have any local staff available. In the SQ case, they don't fly to Baku, so wouldn't have any airport staff available that could make decisions. Everything would have been handled by whomever held the diversions contract.

Although I don't know for sure, I'm sure many nationalities would have required a pre approved visa to enter the country, and that is why SQ would have been unable to simply book hotels (even if available).

With the QF1 incident, it returned to SIN - so most nationalities probably entered visa free, or still had a visa current as they had just left a few hours earlier. Much easier to organise hotels etc..

 

[defurax]

Re: SQ's GYD A380 incident

I was searching the web to see if SQ or Airbus had explained what went wrong with the door on the SQ flight, but I only managed to find this Reuters article mentioning multiple times that the A380 has a "door problem" (UPDATE 1-AIRSHOW-Airbus reassures on A380 door problems | Reuters). No real insight into what the problem is though, but they don't seem too concerned. I feel the SQ incident was relatively serious, no? Anyone with more details?

 

[woodborer]

AFAIK only a preliminary report so far. http://www.mot.gov.sg/news/Airbus-A380-Diversion-to-Baku-Azerbaijan-Investigation-Update.pdf

 

[defurax]

AFAIK only a preliminary report so far. http://www.mot.gov.sg/news/Airbus-A380-Diversion-to-Baku-Azerbaijan-Investigation-Update.pdf

Thanks for that!
This must be frustrating for a crew: "The flight crew declared MAYDAY to Kabul Air Traffic Control (ATC) during the descent but did not get a response."

 

[jb747]

Thanks for that!
This must be frustrating for a crew: "The flight crew declared MAYDAY to Kabul Air Traffic Control (ATC) during the descent but did not get a response."

Nothing surprising in that. Contact with Kabul was always problematic on any of those routes. Getting the message out to the other aircraft near you is probably more important anyway.

I'd be very curious to see a time trace of the event. Just when did they notice that the cabin was climbing, and at what rate was it doing so? The hole was quite small, and with the packs pushing air into the aircraft, I'd expect the rate of climb (of the cabin), wasn't all that fast. And why drop the masks at all. They aren't needed, and the checklist won't call for them, unless the cabin exceeds 13,800'.

I'd always wondered why they flew past Ashgatbat. Nevertheless, very strange that they did not accept an aircraft that had declared a mayday. Equally strange, having declared a mayday, that you'd do so anyway.

As for the door itself, apparently the skin had cracked along the top strip. This is above all of its framework, so the integrity of the door was not an issue. I think the rubber weather strips along the top have been fluttering, and that's ultimately causing cracking. At the moment there is a constant inspection regime on the doors, which will continue until Airbus come up with a final fix.

 

[defurax]

Contact with Kabul was always problematic on any of those routes.

Do you mean contact with Kabul airport was problematic or all contacts with any Afghan ATC? I thought flights had to contact ATC in each country they are flying over or is there "regional ATC"?

 

[serfty]

AFAIK only a preliminary report so far. http://www.mot.gov.sg/news/Airbus-A380-Diversion-to-Baku-Azerbaijan-Investigation-Update.pdf

Not much more than the preliminary report. I find using the AvHerald site gives pretty up to date information but nothing since early March, a week after the MOT report: Incident: Singapore A388 near Baku on Jan 6th 2014, loss of cabin pressure

Had a good look at a door last night. The section that is bent out of shape on the SQ aircraft is a non structural item...basically a large rubber/ plastic panel. It's quite flexible, and looks to simply be part of the weather sealing for when the aircraft is on the ground. It could certainly make a lot of noise if it came adrift and started flapping in the breeze, but it couldn't affect pressurisation.

...
As for the door itself, apparently the skin had cracked along the top strip. This is above all of its framework, so the integrity of the door was not an issue. I think the rubber weather strips along the top have been fluttering, and that's ultimately causing cracking. At the moment there is a constant inspection regime on the doors, which will continue until Airbus come up with a final fix.

The door had been inspected a fortnight earlier:

...
door D3L had been inspected by maintenance on Dec 23rd 2013 following reports of noise from the door. No anomaly was found except for a slightly worn seal at the door's upper edge. The defect was deferred permitting rectification within 120 days. ...

Some images from the AvHerald site:

 

[MEL_Traveller]

i guess timely given recent events - SQ put down in Azerbaijan 9somewhat 'safe' i guess) - but for those flying over Ukraine... if there was a fire on board, requiring an immediate landing... where exactly were they planning to do a diversion in those sorts of areas?

 

[jb747]

i guess timely given recent events - SQ put down in Azerbaijan 9somewhat 'safe' i guess) - but for those flying over Ukraine... if there was a fire on board, requiring an immediate landing... where exactly were they planning to do a diversion in those sorts of areas?

It's not any different to flying over a large mass of water. I'd expect that if they'd really wanted to, Ashgabat would have been used. Beyond that, the next airports are in Pakistan. Next decent choice (along the route) is Delhi.

 

[MEL_Traveller]

It's not any different to flying over a large mass of water. I'd expect that if they'd really wanted to, Ashgabat would have been used. Beyond that, the next airports are in Pakistan. Next decent choice (along the route) is Delhi.

Agree flights over water are similar, and maybe there is nothing that can be done for those... but if flying over land, would airlines choose routes which could allow them immediate landing if required? (I'm thinking here of fires such as those on SR111 or AC797... those requiring immediate landing)

 

[jb747]

Agree flights over water are similar, and maybe there is nothing that can be done for those... but if flying over land, would airlines choose routes which could allow them immediate landing if required? (I'm thinking here of fires such as those on SR111 or AC797... those requiring immediate landing)

Well, if they went back to flying biplanes, then they could land on any paddock that happened to be around. The simple reality is that there are many occasions on which airfields that you can reasonably use are few and far between. The 380 cannot operate to the vast majority of runways (for many reasons), so unless you're prepared to throw the aircraft away, there is often quite a gap between useful bits of tar.

Choosing routes based on being able to land in a short period, is how things were done on twins before the advent of ETOPs. It was very restrictive, and meant that many flights were much longer than they otherwise needed to be.