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View Full Version : So, why arn't passengers kicked out of planes before they crash ?















JDarvall
4th May 2006, 12:03 AM
stupid question. yes ? :confused: .... I've been watching that show 'air crash investigations' a couple of times. Uno, on TV where they detail the reasons behind many of the major airline cashes.

Apart from putting up with being told the story, over and over again after every advertisement break it is kinda interesting, I think.

But it occured to me, that in many of the crashes, there seemed to be a lot of flying around waiting for the inevitable. Time better spent kicking people off the plane with parachutes...

Whats the reason behind there being no kind of passenger parachute system in commercial aircraft ?

- Can't the planes fly slow enough ?
- crowd control being too much with all the panic ?.....then why not just have a ramp out the back, lock the seat belts so they can't undo, and just wheel the passengers out the back on rails, with kinda automatic parachute deploy like paratroops in those WII war movies ? Who cares if they ##### themselves,,,better than dying.
- ejection seats ?

I know there must be plenty of major problems to overcome to work some kind of parachute system.....but, I'm guessing my chances of survival would be greater attempting to get me off than on the plane when it hits the ground. Surely its not all about money again is it ?

Millions of dollars are often spent in other fields to just save a couple of lives. How about the 300 odd lives in a 747, when all 4 engines stop.

Skew ChiDAMN!!
4th May 2006, 12:17 AM
I suspect it has more to do with cost/benefits than anything else.

It's cheaper for them to settle over the occasional accident than it would be to install & maintain some sort of parachute system AND pay the increased fuel costs for every flight. Weight = expense. Expense = less profits. Also, as with seat-belts when they were first introduced in cars (before legislation made 'em mandatory), they're not good PR and would probably cause loss of sales.

After all, they're in the business to make profit; passenger safety is only top priority when it can be done cheaply or is mandated.

Cliff Rogers
4th May 2006, 12:25 AM
Contrary to what you see on the tele, apart from the odd bomb without warning or an occasional hijacker flying into the side of a building, most problems actually happen during take off & landing & there is fugall time to do anything.

PS. BTW, what happens if you did have an automated eject system that decides to offload 300 passengers at 39,000 ft. at 800KPH in the middle of the Pacific?

That is about 11.7 Kms up, the human body needs oxygen about 14,000 ft. (about 4kms), 800KPH well rip your eyeballs out, & if you do make it down to sea level alive, how long will it take to find you still alive in the middle of the pacific if they don't stick an individual Eperb on every passenger?

Am I being too negative here? :D

JDarvall
4th May 2006, 08:59 AM
Am I being too negative here? :D

:D No, thats fine, just won't be taking too many trips to Disney land in a hurry.

echnidna
4th May 2006, 09:19 AM
So why don't they stick some HUGE chutes on the plane itself so plane & people all come down safely.:)

Bodgy
4th May 2006, 09:28 AM
Like everyone says, just not worth it. Air travel is the safest of all forms of transport. Its just that when theres a crash, a lot of people die in a fairly spectacular manner. Its about 100 x safer than driving a car.

Apart from the boring nonsense we sit thru every flight about passenger safety, with the hosties waving their arms around and the dreadfully earnest and sincere voice of the announcer, its all just a bit of PR.

The reality is that if there's a crash one simply prepares for ones anal sphincter to travel up thru ones cranium and briefly meet with all the other passenger body parts, somewhere near where the front of the plane used to be.

Groggy
4th May 2006, 10:23 AM
Here are a few reasons:

Most accidents occur below 5000 feet. This means for a commercial airliner it would not work as passengers could not egress in time. Also, you'd have to wait for that guy who must get his bag out of the overhead.:rolleyes: .

Weight. A 747ER max takeoff weight is in the vicinity of 900,000lbs. A parachute suitable for the entire aircraft would weigh thousands of pounds. The F111 currently in use by the RAAF has a module that ejects. It has a number of chutes that total about 150 pounds to hold a 3000lb module. This gives a ratio of around 1:20. Very rough application of the same ratio requires a 45000lb chute. Allowing a drop of 15000lb due to technology improving since 1970, there is a need for 30000lb of chutes (note this is without structural strengthening).

30000lb is the equivalent of 150 passengers. The cost of Oz to California just went through the roof.

Flaws.
A large chute over the aircraft would be susceptible to any fire that may have disabled the aircraft.
If the aircraft landed in water, the chutes (huge, football field size) would cover the plane and drown the passengers.

Individual chutes
Passengers are not trained, would panic and block exits - meanwhile the aircraft would crash. Assuming of course they are able to move at all due to rapid decompression, oxygen deprivation and induced 'g' forces from an out of control airplane. Note that during WWII a number of aircrew died wearing chutes because they could not physically get to an exit. Individual chutes are large and (all together) would weigh more than a single, large aircraft chute. They would need to be stowed near the passenger who will use it (like the life vest) but won't fit under a seat. To open the doors in flight would require re-design and more weight. Ejecting a door in flight would likely cause further damage to control surfaces, so the door would need to open inwards. Before that can occur the aircraft must depressurise. Now there really is a problem.

Scenario: Four engine failure at 28000 feet, cabin intact. Pilots not sure what problem is or if relight is possible. Pilot identifies problem as volcanic ash injestion and commences re-light procedures. Meanwhile pilot decides an evacuation is possible and commences decompression at around 16000feet. Cabin crew are trying to get parachutes and life preservers on passengers (over water).
Decompression is completed at 8000 feet and doors opened. Some pax refuse to jump, taking valuable time, most get out. Pilot manages to relight number one at 5000 feet, #2, 3 and 4 shortly thereafter. Surviving passengers sue the airline, pilot, crew, government, FAA, rescue agencies and anyone else they can think of. Families of the deceased sue everyone, including the survivors.

Basically, although a good idea, the weight added would make the aircraft uneconomical to fly. The risk of an accidental deployment of a chute would require a large inspection schedule for safety purposes. This means more down time and increased ticket costs to offset the maintenance costs. The ejection of passengers in flight may also require overboard venting of fuel to keep the planes balance (trim) manageable. All this takes time they do not have.

[looks up]

I've rambled a bit haven't I? Anyway, if it was simple it would have been done. Remember the pictures of the capsules returning from space? Now scale that up to a 747, remembering a capsule will fit inside a 747 cockpit.

Wongo
4th May 2006, 10:41 AM
So millions of aircrafts have to carry an extra several millions of kilograms of parachutes in the air every time, accidents happen and they might save a few lives or they might not.

To be fair, I don’t think it is a feasible solution.

CameronPotter
4th May 2006, 10:54 AM
One thing that is interesting though is the doors are very heavy (I think it was 40 kgs from memory).

Try holding 40kgs at arm's length. Some people can do it, most can't.

The result is that rather than putting the door through the hole like suggested, the instinct is to pull the heavy thing towards yourself. Then, as you try to get out of the plane, you put it out of the way (behind yourself), thus blocking everyone else.

I got this from an aircraft safety inspector who said that even the doors are more there for mental comfort - they certainly aren't a quick exit device...

Cam

HJ0
4th May 2006, 01:44 PM
Flying is for the birds, last I seen none of them hard parachutes:eek: . Unless it's a pet eagle sitting on gw bush shoulder on airforce 1;)


HJ0

kiwigeo
5th May 2006, 04:57 PM
So why don't they stick some HUGE chutes on the plane itself so plane & people all come down safely.:)

A chute system has actually been developed in USA for light aircraft. Wouldnt be practical for a large jet though.

kiwigeo
5th May 2006, 05:16 PM
Apart from the boring nonsense we sit thru every flight about passenger safety, with the hosties waving their arms around and the dreadfully earnest and sincere voice of the announcer, its all just a bit of PR.



Cant agree with you there...people who take notice of safety briefings increase their chances of making a safe exit from a plane in a survivable accident scenario.

During pre flight safety briefings I take note of people around me who ignore the video and make a mental note to be as far away from them as possible in an emergency situation. Theyll be the people frantically trying to get through the emergency exit with their lifejackets inflated or clogging up the escape slide because they've decided to take all their duty free shopping with them.

These same people are the ones who think its cool to ignore the hosties instructions and whip of their seat belts as soon as the plane's tyres hit the runway.....not so cool when the pilot hits the brakes while taxiing and you go head first into the seat in front of you. Not an uncommon scenario....Ive seen it happen three times and on one occasion the person ended up with a blood nose.

CameronPotter
5th May 2006, 05:42 PM
Unless of course they know it verbatim... There is no point listening once you know exactly what they are going to say.

JDarvall
5th May 2006, 05:47 PM
Cant agree with you there...people who take notice of safety briefings increase their chances of making a safe exit from a plane in a survivable accident scenario.

etc...

Of course, your right.

But, I suppose though, its hard to want to remember whats being said....

If its incredibly unlikely being in an airline crash to begin with....then, the odds of surviving make it far, far more unlikely.....and even more unlikely (I'm only guessing) , if you do attempt to remember what the lady says, is remembering this important stuff ,amongst all the panic when its time to remember it. I think most would have to be well trained to be able to make good decisions in such situations; which rules out most of the passingers doesn't it.

Honesty, I've only taken a flight a couple of times, and each time they start describing these things, I switch off. But thats just partly cause I'm slowly ,mentally undressing the hostess closest,,,,,which is something that one ends up doing to all the hostesses by the time you land, I think. Good sorts arn't they. Makes me wish I'd became a pilot......:o

Skew ChiDAMN!!
5th May 2006, 05:48 PM
Cant agree with you there...people who take notice of safety briefings increase their chances of making a safe exit from a plane in a survivable accident scenario.

Errrmm... he did say "Apart from the boring nonsense we sit thru..."

And it is boring after a few performances... you're certainly not paying attention; you say you're looking around to see who else isn't listening. And I imagine that some of them notice that you aren't listening and consequently decide to avoid YOU in case of emergency. :rolleyes:

Bodgy
5th May 2006, 08:06 PM
But thats just partly cause I'm slowly ,mentally undressing the hostess closest,,,,,which is something that one ends up doing to all the hostesses by the time you land, I think. Good sorts arn't they. Makes me wish I'd became a pilot......:o

You obviously don't fly fly Quantas, American or BA, Apricot. Still its sort of comforting having yer Mum serve you dinner (thats dinner as a generally descriptive word for anything vaguely edible, served after 7PM)

Kiwi

You are describing potential chaos after the plane has regained the ground. A little optimistic I think. A more likely scenario is our mutual acceleration from zero to 1000 KPH or more, then back to zero, in a split second. We won't have to worry about duty free, cause it'll all come with us.

I just hope that the voice over man that does the "Ladies and Gentlemen, I MUST have your complete attention" is on board

havenoideaatall
5th May 2006, 10:12 PM
Contrary to what you see on the tele, apart from the odd bomb without warning or an occasional hijacker flying into the side of a building, most problems actually happen during take off & landing & there is fugall time to do anything.

PS. BTW, what happens if you did have an automated eject system that decides to offload 300 passengers at 39,000 ft. at 800KPH in the middle of the Pacific?

Am I being too negative here? :D
The only other technical reason I can think of, is, too many entanglements self or otherwise. We used to get pushed out port and starboard at 1 second intervals with half a second between each side.

We still had blokes getting their parachutes entangled occasionally.:p

At fast speeds, you really need to force out in to the slipstream, in a stable upright position, arms and legs by side, even as slow as 120 knots, or you get a faceful of rivets, or high low twists. This requires stamina and fitness and aggression. This is why paras spend ages drilling it, to get it right even with a 50kg container strapped to a leg.

kiwigeo
5th May 2006, 10:20 PM
Unless of course they know it verbatim... There is no point listening once you know exactly what they are going to say.

I spend half my life flying out to offshore oil rigs in helicopters. Every 2 years I have to tavel to Perth and do a 2 day Helicopter Underwater Escape and Fire Training course. Ive done 6 of these courses over the years but I still watch the pre flight videos prior to going offshore.... complacency is one of the things that can reduce your chances of survival in an emergency situation.

The Qantas safety video is the same each time you watch it..but is your escape route the same each time you fly?

kiwigeo
5th May 2006, 10:40 PM
You are describing potential chaos after the plane has regained the ground. A little optimistic I think. A more likely scenario is our mutual acceleration from zero to 1000 KPH or more, then back to zero, in a split second. We won't have to worry about duty free, cause it'll all come with us.



Bodgy,

Most air crashes occur during take off and landing where the aircraft is travelling alot slower than 1000km/hr. Accordingly a surprising number of air crashes involve survivors. The key factor in surviving such a crash is getting out of the plane as quickly as possible.....people who know where the exits are and how to get out of the plane quickly generally survive and those who don't.....die.

You're obviously a person who has decided there's no chance of surviving an air crash so theres no point paying attention to the pre flight safety videos. I take a different approach and choose to maximise my chances of survival in an air crash situtation by having a plan and an escape route...in fact I usually have two plans and two escape routes. Sounds paranoid but its the way Ive been trained to fly in my work.

Like I said....ignoring safety briefings looks cool....being in an emergency situation and not having a plan or escape route isn't cool.

havenoideaatall
5th May 2006, 10:56 PM
surely looking around and actually looking for the exits, and or reading the safety card is more important than listening to the video or the trolley dolly which often is repeating something you have heard before?

Groggy
5th May 2006, 11:29 PM
Back in another lifetime I was part of a helicopter crew (Iroquois). When training with a particular unit, the Warrant Officer asked one of his trainees to repeat a procedure I had just briefed, he couldn't. The WO directed him to return to camp (on foot), then politely asked me to repeat the briefing. I did so, and he asked a question of each man in turn. Not surprisingly they had the answers.

I'd dearly love to see the hosties able to remove those who can't answer the basic safety questions. Not because I'm bloody minded, but because I don't want to have to go past, through or over them on my way to an exit.

Bodgy
6th May 2006, 11:02 AM
Kiwi

You are correct, I reckon my chances of surviving the impact are next to zilch. However, I do always check where the exits are.

I wish I had the stats, I would mount an argument that goes; chances of the (first world) aircraft crashing 1,000,000 to 1. Chances of it being a survivable crash 300 to 1. Total odds against listening to the 1,223,443,725th repetition of the safety briefing being of use - astronomical.

I have a strong suspicion that these safety things are only to mitigate against damages come any event. The airlines knew about DVT issues for years and only put that stuff about getting up and walking around and exercise up once the courts started awarding damages.

Can you imagine if even 10% of a 747 passenger load actually tried to follow this advice? Chaos.

Hence my cynicism.

Incidentally, cool does not come into it.

Eddie Jones
6th May 2006, 12:42 PM
All the discussion about pre-flight briefings ignores the fact that the hosties are only giving the briefing because legislation says they have to. Just look at their faces. Fixed, wooden smile, far away glazed look in eyes. If you interupted and asked for a point to be clarified, I wonder what they'd do?

My point is they are just blindly following procedure. A case in point:

At Alice Springs airport some years ago, I was waiting for my flight when it became aparent that an incoming F27 (Friendship, propjet of the 60's - 70's) had landing gear problems -ie one main wheel stayed partly up. They circled the tower for a while. then landed with fire crews etc along the runway. Pilot did a great job and no crash. The plane stopped ASAP and everyone disembarked through the rear stairs. Then I realised they all had no shoes on. One of the hosties appeared with garbags full of shoes. They all proceeded to put their shoes back on. Odd you may say? Then I discovered (on the news that night) that the hosties were following their laid down emergency procedures, requiring passengers to remove shoes before going down the escape slides. Makes sense? But the F27 didn't have escape slides!

Groggy
6th May 2006, 01:03 PM
Makes sense? But the F27 didn't have escape slides!Maybe not Eddie, but I guarantee there is a barbie-doll on there with high heels and a knee hugging skirt. She'll move along a bit better without shoes.

Why not just get the high heels off you may ask? Because the hosties are trained across multiple aircraft and you don't want to have confusion, so standard procedures work best.

Finally, you never know when the aircraft will slide off a runway and come to rest in water, so, shoes off, it's easier to swim. I'm sure there are other reasons too.

kiwigeo
6th May 2006, 03:49 PM
All the discussion about pre-flight briefings ignores the fact that the hosties are only giving the briefing because legislation says they have to. Just look at their faces. Fixed, wooden smile, far away glazed look in eyes. If you interupted and asked for a point to be clarified, I wonder what they'd do?



If you interrupted them halfway through the briefing theyd probably get p*ssed off. A normal person would wait untill the safety briefing had finished and then ask any questions.

kiwigeo
6th May 2006, 03:57 PM
What I'd really like to see is all Qantas passengers put into of these, turned upside down and dunked into a 6' deep pool of water. If you can't get the exit doors off and out in 20 seconds you dont get to fly.

Eddie Jones
6th May 2006, 05:09 PM
What I'd really like to see is all Qantas passengers put into of these, turned upside down and dunked into a 6' deep pool of water. If you can't get the exit doors off and out in 20 seconds you dont get to fly.

Oh come on Kiwi! Even I can see it has no rotors, so it won't fly anyhow!

Just joking mate! I did the escape training too in the Navy. Bags of fun, but glad I never had to do it for real!

kiwigeo
6th May 2006, 06:19 PM
Oh come on Kiwi! Even I can see it has no rotors, so it won't fly anyhow!

Just joking mate! I did the escape training too in the Navy. Bags of fun, but glad I never had to do it for real!

The HUET even more fun when one of your fellow passengers decides to throw up his lunch....when that mock up cabin fills with half digested food there's an extra incentive to get that hatch off and get out of there fast!!

kiwigeo
12th May 2006, 08:50 PM
Classic footage on the TV news of a Russian chopper hitting the water and doing what 90% of choppers do when they land on water.....roll over. Think the pilot copped it but the passengers all survived.

Groggy
12th May 2006, 10:11 PM
Classic footage on the TV news of a Russian chopper hitting the water and doing what 90% of choppers do when they land on water.....roll over. Think the pilot copped it but the passengers all survived.The pilots are trained to settle the aircraft in the water, then pull the remaining pitch to slow the rotors as much as possible. They then roll over to use the water to take the remaining rotor energy. If you are lucky the transmission won't tear free and mix in with the passengers. If you are even luckier the rotor won't behead the pilot as they thrash themselves to pieces.

kiwigeo
13th May 2006, 03:47 PM
The pilots are trained to settle the aircraft in the water, then pull the remaining pitch to slow the rotors as much as possible. They then roll over to use the water to take the remaining rotor energy. If you are lucky the transmission won't tear free and mix in with the passengers. If you are even luckier the rotor won't behead the pilot as they thrash themselves to pieces.

Looks like something went horribly wrong.....chopper hit the water with nose down and rotors under full power....you can see why the pilot copped it. Cant see any floats deployed either (assume theyd have 'em fitted) so pilot cant have had much time to deal with the emergency. They were on a safety training flight so I guess most of the passengers would have had a bit of training and possibly done a HUET.

I cringe every time I board a chopper and see the carbon fibre beheading device spinning above my head.