Airbus A320 Crashes in Alps

[FL630]

how plausible is this - the cabin depressurizes for whatever reason, the aircraft starts to descend immediately as you'd want it to do with a depressurized cabin... but unfortunately the mountainous terrain poses a bit of a problem with this immediate descent?

Would a plane automatically descend upon detecting that the cabin pressure had dropped or is it left to the pilots? If it does then how well does it take into account the terrain when performing this rapid descent?

A plane doesn't descend automatically with a decompression, it does require manual input. The first thing to do when faced with a pressurisation problem is oxygen masks on. Nothing else is important at this stage, at 38,000ft you'd have about 15-30 seconds of useful consciousness before you end up a blabbering, yet happy, mess. If it was a rapid decompression (e.g a blown window), you may have less than this as you'll force exhale any air in your lungs, probably along with bursting eardrums, contacts popping out, other "gasses" escaping from your body etc.

Each airline or operator has their own procedure for this, but it goes vaguely like this... masks on (they're horrible to wear and make you sound like Darth Vader), establish communications, diagnose the problem and announce to cabin "cabin crew prepare for emergency descent". If not structural dial a lower altitude into the autopilot window, press level change (a form of vertical navigation which adjusts rate of descent to maintain a set speed speed), deploy speed brakes, disconnect autothrottle, retard thrust levers and increase speed in the autopilot to your maximum limiting speed. This will cause a very rapid descent, easily 4000-5000fpm initially. Once you're in the descent you set your level off altitude, either 10,000ft or the minimum sector safe altitude (depending on the surrounding terrain, such as the Alps). After this is done, call mayday and set your transponder to 7700. Then it's a monitoring game really, just making sure everything is happy and stable, calling altitudes and reducing the rate of descent as you come closer to your level off altitude.

In the case of the GWI flight today, it seems the crew did this. The profile was perfect, the plane maintained track and it looked entirely in control. What happened to the crew after they initialised the descent is what we'll find out over the coming weeks, but from radar traces it looks like a very standard emergency procedure.

They were only over small foothills when they started the descent, but it does make me ask questions why they didn't turn from their track to avoid them as they got lower. However the mountain them impacted was ~8000ft tall, if they set and leveled at a standard 10,000ft they'd have been safe until they got to the larger hills further north east.

furthermore birds don't tend to fly at 38,000ft. They do get bloody close though. I was surprise to read the max altitudes for some:
http://en.wikipedia.org/wiki/List_of_birds_by_flight_heights

Tell you what I'd be bloody confused if I hit a bird up that high, 37,000ft is incredible!

+1 to the BS on the hydraulics too.

 

[dunker]

rip to all

what's the risk of hurtling 10 miles high at 500mph with no lifeboat if somthing goes wrong?

buses in the air plus human error is just wrong.

 

[Edinho]

rip to all

what's the risk of hurtling 10 miles high at 500mph with no lifeboat if somthing goes wrong?

buses in the air plus human error is just wrong.

When I read a book on aircraft safety a while back it said that that sort of looking at risk is false. Yes you can't jump out of a plane at 38,000ft at 500 mph if something goes wrong. People seem to think that on a boat you can swim to safety or on a bus or car you will somehow just survive a crash and walk away. Reality is on a boat you will drown and freeze to death, in a car or on a bus you will likely die from trauma not walk away.

 

[Diddums]

+1

I can't comment on the validity of the story, I can only go by what I've been told. He has loads of them though, mostly about Air Zimbabwe. If the safety inspectors in Zim are anything like their government, nothing will matter as long as a few palms are greased.

 

[Tefal]

No, it's not. An aircraft receives some sort of maintenance before every take off

yes but shortly after a major service its possible something was done incorrectly. the royal flight or Flight 5390 for some of the high profile examples.

 

[leaskovski]

A single engine failure doesn't mean that an aircraft will suddenly plummet ouf of the skies like a stone. They still have their momentum to carry them a bit forward and pilots are generally trained to use flaps / ailerons combined with the remaining engine (s) to generate forward motion to keep the plane airborne until such time that it is possible to land safely.

As for the engineering thing, a friend of mine is an aircraft technician for SAA and some of the stories he's told me would easily make some folks never want to fly again.

Like on one occasion using a hydraulic system from a completely different aircraft to power some or other moving bits, but only on one wing. The other wing had all the original gubbins, so they relied on the on-board systems to keep the aircraft stable during a long haul flight as the two systems had completely different calibration parameters.

I have similar stories from my old job about the passenger ferry industry as well.

 

[beachBOYken]

so sad this

It got me thinking, why don't airliners have camera's fitted inside the cockpits?

This could give air investigators a lot more insight in what could have gone wrong.

 

[MooMoo444]

Would be potentially grim viewing, but I do agree it would give a lot of insight into the final moments of the aircraft and what the pilots were doing at the time.

 

[Hyburnate]

It's being considered last I read.

 

[hellarda]

so sad this

It got me thinking, why don't airliners have camera's fitted inside the cockpits?

This could give air investigators a lot more insight in what could have gone wrong.

I suppose it could be to do with how much data the data recorders can store?

On a 14 hour flight, 14 hours of audio is a relatively small amount to store compared to 14 hours of video. However one would assume they'd be able to store more data in the flight recorders now?

EDIT: Ignore me, half asleep obviously it wouldn't be recording all 14 hours, but still 2 hours of video is a lot more than 2 hours of audio

 

[Burned_Alive]

so sad this

It got me thinking, why don't airliners have camera's fitted inside the cockpits?

This could give air investigators a lot more insight in what could have gone wrong.

All round really, one in the cockpit, one forward facing, one facing each wing, one facing the tail. Would certainly help explain exactly what happened to the plane in its final moments. I assume its a cost versus risk debate, as the technology is already available. Most planes already have external video feeds into the cabin.

 

[Blinkz]

RIP to all those onboard. A very sad day in aviation.

It isn't helpful to guess at the cause. There really isn't enough information to make a good diagnosis of what happened. FL630s suggestion of an emergency descent gone wrong has a lot of holes in it to end up as a crash. I appreciate you are trying to inform people but sometimes a little information without the knowledge can lead to problems!

Once the FDR and CVR are examined we will be in a much better place to learn from whatever happened and make sure it never happens again.

One of the most important things in aviation and in and safety critical profession is a open reporting culture. If a mistake is made then everyone has to feel that they can put their hand up and say 'sorry I made a mistake' If people start pointing fingers and assigning blame, which ends up in punishment then mistakes start to get brushed under the carpet which leads to far greater problems.

 

[FL630]

I agree it's purely speculation, I did state this in both of my posts, I can only guess from the data given. There are holes in my theory; why were masks not put on by both crew? Were they possibly faulty? Why did they select 6400ft in the MCP? I can't get my head around this but I can't think of any other explanation for a perfectly controlled looking emergency descent profile with the data given by the likes of FR24. Lots of holes, but perhaps this time they lined up.

Given your name, signature, location and altitude, I'm going to guess you're a pilot for an operator flying North American wild horses, so it'd be interesting to hear your views too.

Speculation is a dangerous game in aviation, but going from my personal experience to say what I said is what I believe a possible cause. We'll no doubt see some answers in the next 48hrs, grim as they are.

I do agree with the open safety culture, sadly not all airlines follow this.

 

[Minstadave]

so sad this

It got me thinking, why don't airliners have camera's fitted inside the cockpits?

This could give air investigators a lot more insight in what could have gone wrong.

And also have a data link that sends black box data out in real time rather than trying to find them on the bottom of the ocean. I know this has been proposed previously, would make a lot of sense if the technology was available, which must be possible if you can get wifi on some flights nowadays.

 

[Blinkz]

I agree it's purely speculation, I did state this in both of my posts, I can only guess from the data given. There are holes in my theory; why were masks not put on by both crew? Were they possibly faulty? Why did they select 6400ft in the MCP? I can't get my head around this but I can't think of any other explanation for a perfectly controlled looking emergency descent profile with the data given by the likes of FR24. Lots of holes, but perhaps this time they lined up.

Given your name, signature, location and altitude, I'm going to guess you're a pilot for an operator flying North American wild horses, so it'd be interesting to hear your views too.

Speculation is a dangerous game in aviation, but going from my personal experience to say what I said is what I believe a possible cause. We'll no doubt see some answers in the next 48hrs, grim as they are.

I do agree with the open safety culture, sadly not all airlines follow this.

I appreciate you said that it was speculation, and I'm not trying to teach you to suck eggs so to speak. I'm just saying that on a public forum it pays to be careful with what information you share, as I said a lot of information without the appropriate knowledge or understanding can sometimes be more trouble then it's worth.

I just believe that guessing without all the information is inappropriate, we've all seen what rubbish can appear on the news from people guessing and sensationalising it all!

As you say I fly as well and have over 5000hrs flying different types of Airbus as well as a little time on Boeings. I'm more then happy to discuss the technical and human factor issues with colleagues and those who have the knowledge and can have an educated discussion about it. I just think a public forum isn't the best place for such a discussion.

 

[Third Opinion]

so sad this

It got me thinking, why don't airliners have camera's fitted inside the cockpits?

This could give air investigators a lot more insight in what could have gone wrong.

Sounds like a good idea. It apparently gave Virgin Galactic a head start on their investigation.

Be good to see the instruments too. I read (no idea if it is true) that the A320 crash in 1988 at the airshow had conflicting information between pilot and black box.

Although it was claimed at the time it was being flown by computer it was the captain at the controls. He apparently claimed the altimeter was reading 1000ft yet he hit the tree line.

 

[DJMK4]

Iv said this a few times, even in previous cases.

It would give you an insight as to what was visually happening with the general cockpit and crew at the time.

 

[DJMK4]

Although it was claimed at the time it was being flown by computer it was the captain at the controls. He apparently claimed the altimeter was reading 1000ft yet he hit the tree line.

Was supposed to be 100 ft flyover with landing gear down, and was supposed to throttle up and climb nearing the end, however it was actually flying at 30ft, I think it went in to alpha protection mode so didnt respond to any attemps in the small limited time they had.

 

[Felon]

Cockpit voice recorder;

Whilst it looks badly damage, apparently the data should be intact.

 

[Westyfield2]

Bent bit on the right is the power supply and circuit boards - data is in the big circle in the middle.
Kinda amazing what forces those things can survive!