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View Full Version : SQ B772 returns to SIN after loss of cabin pressure


gonococcus
2nd Feb 2008, 13:05
http://www.channelnewsasia.com/stories/singaporelocalnews/view/326502/1/.html





SINGAPORE : A Singapore Airlines Boeing 777-200 plane flying to Beijing had to return to Changi Airport some 90 minutes after takeoff due to loss of cabin pressure on Saturday afternoon.

Officials say Flight SQ 802, carrying 232 passengers and 13 crew, suffered loss of cabin pressure at an altitude of 36,000 feet.

So the pilot sent the plane first to 32,000 feet and then to 10,000 feet.

Because of the rapid 6-minute descent, oxygen masks were deployed.

However these were safely removed once the plane reached 10,000 feet, and was stable.

SIA says the captain, in accordance with safety procedures, immediately initiated a return to Singapore - the nearest suitable airport.

The plane landed safely and without incident at 1.48pm local time.

Passengers were transferred to a different aircraft to continue their journey to Beijing.

SIA says a detailed investigation is underway and apologises to passengers inconvenienced by the delay. - CNA/ch

parabellum
3rd Feb 2008, 07:04
If you are at FL360 and 90 minutes out of Changi then the 'nearest suitable' airport isn't Changi, but, provided the condition was contained then I would have opted for a low level return to my base where sorting out the problem would have been a lot easier than, say, Dar Nang.

Wornout Rubber
3rd Feb 2008, 07:29
Parabellum,

If one or more of your passengers died during your low level return to base as a direct consequence of oxygen deprivation earlier, and you had elected not to proceed to the nearest airport, you would need a very good lawyer to get you out of charges of gross negligence and involuntary manslaughter.:* Passengers may seem "alright" after a rapid descent, but with 300 or so passengers on board, there will be some with heart ailments etc., who need to get on the ground fast. Why take the risk?

Capt Fathom
3rd Feb 2008, 08:22
Low Level returns to base may not be a problem in Australia, but overseas they could be a nightmare.

Cruising along in an airliner at 10'000ft is far from ideal.

High terrain, Military airspace, Restricted airspace, lack of communications, and controllers that probably have no understanding of what you are doing and where you are going.

As a first rule, it is generally best to land as soon as practicable! After that, anything is possible.

Sir Richard
3rd Feb 2008, 09:10
Nearest Suitable does not mean Nearest Usable ! (Unless you are on fire :eek: )

For example, LHR-JFK, pressure loss at 10W. Shannon may be nearest and suitable and usable, but availability of replacement aircraft, medical facilities, crews, engineering etc. means that the contained situation makes the return to LHR more Suitable.

hamil
3rd Feb 2008, 09:25
What’s the difference in terms of safety if an airplane (a SE or a WB) flies at FL100 or FL360 in a controlled airspace? It is safer only at higher levels, isn’t it? Ok, those fellows that died on a B737 collision in Brazil thought the same.
If there is not a medical urgency or any other situation that affects the aircraft performance, a pilot doesn’t need to rush looking for an immediate landing after a (rapid or slow) depressurization. Everyone knows that a jetliner can fly very well (nicely and safely) at FL 100 otherwise I can’t imagine how short sectors (including in congested airspace) can be made. Searching for options in that area it’s easy to find out that VVTS, Brunei or heading to HKG aren’t better than a 180 degrees returning to SIN, coincidently SIA home base, a place with a good support, several hospitals and an extra airplane as well.
Crews must not fly an airplane considering what a lawyer would say. They should consider first what is the appropriate option for everyone involved, including their company … this is part of their CRM I suppose.

Wornout Rubber
3rd Feb 2008, 10:18
Hamil,

A rapid depressurisation is a serious event. Not all passengers are able to put on their oxygen masks. Not all drop down as they should, and the elderly, young and infirm will not always put them on. To then put them through additional, unnecessary unpressurised flight at 10,000, exposing them to further oxygen depravation for the sake of keeping the Company happy, is not only irresponsible but dangerous.

Hospitals are not much help to you if you are already dead.:ugh:

bjkeates
3rd Feb 2008, 10:27
It doesn't say "rapid depressurisation" anywhere in the article - it might have been a slow loss of pressure due to a leak or faulty valve or something. If that was the case, surely an alarm would have sounded as soon as it started to become unsafe... it doesn't necessarily mean the passengers were being starved of oxygen for a period of time, as would happen in the case of explosive decompression and subsequent inability to put on an oxygen mask. It sounds to me like, in this case, there was very little drama.

itaintgoingtothemoon
3rd Feb 2008, 10:28
Just one man's opinon, but this looks very much like a commercial decision.

Knowing Singapore a little, I think it unlikely the commander made this decision without a fair amount of prior consultation to the company.

get-home-itis again?

EatMyShorts!
3rd Feb 2008, 11:33
Not all passengers are able to put on their oxygen masks. Not all drop down as they should, and the elderly, young and infirm will not always put them on....don't forget that these masks are mostly for decoration and "a good feeling" only, the positive effect in terms of O2 is very small, ask any doctor.

Flightsimman
3rd Feb 2008, 13:23
Personally I think it's wise to divert to a city that at least has some half decent restaurants!

:ok:

hamil
3rd Feb 2008, 14:09
A rapid depressurisation is a serious event. Not all passengers are able to put on their oxygen masks. Not all drop down as they should, and the elderly, young and infirm will not always put them on. To then put them through additional, unnecessary unpressurised flight at 10,000, exposing them to further oxygen depravation for the sake of keeping the Company happy, is not only irresponsible but dangerous.

Rapid descent can be a serious event but it is not a Russian roulette where some passenger will die or suffer severe injuries. After reaching a safe altitude F/A’s have to check cabin area and if medical assistance is required a decision to land as soon as practical should be considered. If the situation is under control there is absolutely no reason to put a loaded 777 in Ho Chi Minh or Brunei, for instance.


...don't forget that these masks are mostly for decoration and "a good feeling" only, the positive effect in terms of O2 is very small, ask any doctor.
Sorry man, if you are sure about it this is a premeditated crime. Therefore, Boeing, CAAS and SIA must be prosecuted.

get-home-itis again?
Not really. Air-ground coordination is one of the possibilities to use ACARS. That`s why airlines invest a lot of money to install it on every airplane.
Captain`s decision must be based on several aspects and returning to SIN, 90 minutes away, over the South China Sea can be considered as a good decision in this case ... or am I wrong?

Personally I think it's wise to divert to a city that at least has some half decent restaurants!
If someone likes spicy food or some strange broth SIN is a perfect place for a stopover :mad:

4PW's
3rd Feb 2008, 23:05
"I would have done it this way because I've sat in front of a mirror and pretended this very scenario happened to me. I made up my own words, and I didn't panic. And now, seasoned aviator or aviatrix that I am, though I've not actually flown a real airplane, I can categorically state without reservation or shred of humility that the SQ fellow, seasoned aviator, unlike me, made a grave error of stupendous proportions and he better watch out because, because, because..."

Wornout Rubber
4th Feb 2008, 04:39
Regarding a rapid depressurization and subsequent actions, we do not know the full details of the SQ incident, and indeed whether they suffered a rapid depressurization at all.

However, if we look at an event in detail, we can perhaps work out the best option if it really does occur.

1. There will be an initial loss of pressure, which may be very sudden, and may be accompanied by an increase in noise and sudden changes in temperature.
2. The oxygen masks should now auto deploy. Some, however will not. (As demonstrated in Air Tests).
3. The passengers, now probably in a state of mild, moderate or extreme panic will (perhaps) put their oxygen masks on. Some will take a considerable time to put them on, others ( especially the young, elderly or infirm), may not even put them on at all.
4. About 6 panic stricken minutes later the aeroplane levels out at say, 10,000 feet, and the passengers remove their masks.

The cabin attendants can now assess the state of the passengers.

However, how do say 14 cabin attendants, who are not doctors or qualified nurses make an accurate assessment of the medical condition of say 300 passengers,who have just experienced a rapid depressurization?

The passengers may appear to be alright, but what is their real condition?
How much have they been affected by the event?
Did some of them not have their masks on during the descent?
Do some of them have heart ailments, and are perilously close to having a heart attack?
The majority of passengers will also probably be in a state of shock.

So what is the best course of action for the Captain now? (Assuming of course, the aeroplane structure is sound, and the cause of the rapid depressurization has been identified),

A) Not land at the nearest suitable, and land somewhere else where they may be a replacement aeroplane. Fly there at 10,000 feet, which is in itself an abnormal cabin altitude to fly at, and exposes the passengers to even more oxygen depravation than what they are normally used to when they fly. (Cabin altitudes are normally in the 4,000-6000 foot range). Keep the passengers in a state of shock and pehaps panic for longer than necessary because you need to get the aeroplane to where the replacement is. Risk having someone perhaps dying as a consequence, but no matter, the aeroplane will get back to base, or

B) Land at the nearest suitable aerodrome. Panic over, passengers can breathe sea level oxygen again, and real doctors can attend to those who need attention. If someone dies on finals, you would have done the best you could.

On speed on profile
4th Feb 2008, 10:08
Wornout Rubber,

You werent the Captain! You didnt make the decisions! You most certainly dont have all the facts!

It sounds like this incident scared you and you werent even on the aircraft. If you are that bothered about it, I suggest you refrain from flying from now on!

OSOP

P.S. Amongst other things, on the aircraft I fly, the cabin regularly reaches 8000' and has been higher so I am afraid your arguments are wearing extremely thin!

Wornout Rubber
4th Feb 2008, 10:45
On Speed on Profile

I am not talking about what you would do on your Cessna 150 flying at 8,000 feet.

This is about us big boys flying the big jets.

It would help too if you read my first sentence:

"Regarding a rapid depressurization and subsequent actions, we do not know the full details of the SQ incident, and indeed whether they suffered a rapid depressurization at all.":ugh:

On speed on profile
4th Feb 2008, 12:34
Warnout Rubber,
Regarding a rapid depressurization and subsequent actions, we do not know the full details of the SQ incident, and indeed whether they suffered a rapid depressurization at all.

By that statement alone, you should just stop, pause and consider exactly what your opinion is before you go spouting off! Especially if you operate as one of the "big boys flying the big jets".

By the way, IMHO, trying to make your self more important by commenting on my credentials when you know nothing about me just makes you look more pathetic. I guess I better get back to my C150! :hmm:


OSOP

golfyankeesierra
4th Feb 2008, 15:17
Wornout rubber,
you don't need to fly a 150 for your cabin to reach 8000'.

From the A330 FCOM:
The cabin altitude is
limited to 7350 ft for flights longer than 2.5 hours, and 8000 ft for flights shorter than 2.5 hours.
It reaches these altitudes at F410

hamil
4th Feb 2008, 15:32
Hi Wornout,

I don’t know if you’ve already had in your career a real situation like you described. Anyway, it is your decision and based on few details about that incident IMHO initially that crew did what was the best option in terms of safety, because we don’t know how far they were from SIN, we have absolutely no idea about weather en route, in SGN, Brunei and other alternates, etc. And also we don’t know if those guys decided to stay at 10,000 ft or at 8,000 ft (the same cabin altitude maintained on a B737 on FL 370) after reaching a safe altitude. In short: only hypothesis and few facts.
But I’m sure: SIA is a serious airline not a kindergarten.
Meanwhile it’s time to sit back and relax waiting for more information :ok:

ACMS
6th Feb 2008, 16:25
Jesus guys take a breath.................I don't know exactly what happened on the SQ 777 that day, do you?

If the situation warranted it I see NO problems returning to SIN.

Give the guy a break.

faheel
6th Feb 2008, 21:29
He was passing through 32000 on climb out of Singapore it was more like 90 nm not 90 mins, he did the right thing and went back to Singapore, case closed (with the exception as to why the a/c depressurised):ugh:

Akali Dal
6th Feb 2008, 23:42
Had it been BA or other western airline, skinheads would been falling over their heads congratulating the crew on what a great job they had done. Alas, it's an Asian carrier and a damn successful one, so the worn outs are all over to skin the crew, hoping the skipper might have been an Asian too...so they can have a great time laughing and making monkey jokes in the bars and crew rooms. Pathetic!!!

Look at the BA incident at LHR; notwithstanding that the crew did a great job, there remain questions on their debriefs regarding the fuel X-feeds etc, yet ppruners remain cool and gentlemenly ...no overt aspersions cast on the crew; why? BA is western and crew presumably caucasian!:ugh:

Balthazar_777
7th Feb 2008, 00:07
How do you know the Captain on the SQ flight wasn't caucasian?

With the armchair critics on the first page decrying the captains decision to divert to SIN and now this gem of racial frustration trying to derail the conversation, this is definitely one of pprunes crappier threads.

Down to the bottom we go.

212man
7th Feb 2008, 00:16
"I would have done it this way because I've sat in front of a mirror and pretended this very scenario happened to me. I made up my own words, and I didn't panic. And now, seasoned aviator or aviatrix that I am, though I've not actually flown a real airplane, I can categorically state without reservation or shred of humility that the SQ fellow, seasoned aviator, unlike me, made a grave error of stupendous proportions and he better watch out because, because, because..."

God, there are some weirdos on this forum. Please moderators step in and remove them! This isn't what we all signed in for all those years ago when Pprune was new and vibrant. I know you're busy.:{

Bushfiva
7th Feb 2008, 00:38
hoping the skipper might have been an Asian too

Not so much a chip on your shoulder, as an entire serving of french fries.

preset
7th Feb 2008, 01:06
Jesus guys take a breath.................I don't know exactly what happened on the SQ 777 that day, do you?

If the situation warranted it I see NO problems returning to SIN.

Give the guy a break.


First sensible comment I've read on this thread. :D

mohdawang
7th Feb 2008, 06:04
Balthazar; note A. Dal wrote ".......hoping the skipper might have been an Asian too... " So he he/she had surmised that he could be a poor caucasian working for an Asian carrier. And I thought that I have a dodgy understanding of English, coming from a 3rd world basket case!

cargo boy
7th Feb 2008, 06:50
So... we have a newspaper report about a depressurisation incident. As is typical of most newspaper reports, it is extremely inaccurate and full of sensationalist fiction.

Now we have a whole bunch of armchair 'experts' who latch on to the sole report from the newspaper and spout off with their theories of what did and didn't happen as though the report was accurate and factual. It even descends into a a racially motivated slagfest which is based on assumptions too. :ugh:

90 mins turns out to actually be 90NM. The whole lot of you should be ashamed of yourselves. You waffle on here as though you actually know what you are talking about when it becomes perfectly clear that none of you have ever actually experienced a decompression and if you did it would most likely be because you programmed it in to your flight sim PC game!

Apart from the few who have pointed out that there was a typo and that you shouldn't assume anything until you have all the facts, the rest of you are obviously not real pilots but pretenders who would like all and sundry to believe that you are skygods. It is pathetic to watch and read a bunch of fantasists trying to make out they are knowledgeable pilots when in fct all they do is make arses of themselves to those of us who know better. :rolleyes:

Barney Rock
7th Feb 2008, 07:12
What Akali Dal wrote may be unpleasant but there is a grain of truth there. Skygods and self professed God's gifts to aviation are constantly prowling Pprune to cast our fellow aviators from the third world in bad light. Having worked both in airlines in the West and the Orient, I fully understand the frustration of our less fortunate, but highly professional and proficient, bethren trapped in third world airlines especially when blanket, sweeping statements are made.