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

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.

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?

Originally Posted by Cliff Rogers

Am I being too negative here?

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

So why don't they stick some HUGE chutes on the plane itself so plane & people all come down safely.

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.

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. .

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.

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.

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

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

Originally Posted by echnidna

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.

Originally Posted by Bodgy

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.

Unless of course they know it verbatim... There is no point listening once you know exactly what they are going to say.

Originally Posted by kiwigeo

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......

Originally Posted by kiwigeo

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.