Why are airplanes equipped with lifejackets, but not with parachutes?

Answer 1

Well, it's really a false sense of security. When a commercial jet is about to ditch in the water , chances are that it will be ripped to shreds rendering your life vests useless. Better off crash landing on the ground - despite the possible fire. As for parachutes..... - do you really think that most people will know how to put them on? Also, how do you expect to disembark a troubled plane during flight??? Even if you could, you'd probably lose consciousness instantaneously as soon as the cabin is depressurised - and if the plane were at an altitude where pressurisation were not an issue, you'd probably be ripped to sh reads once you jump (if you had the guts to do so - which most passengers don't). Remember , you'd be going from zero to a couple of hundred miles an hour MINIMUM - in an instant, not to mention the wake turbulence caused by the engines. Not feasible - just a wasted expense.

Answer 2

There seems to be this very popular idea that passengers are flying along at 35000 ' minding their business and all of a sudden something goes terribly wrong with the A/ C they're in. Now they are trapped and they know they are all going to die. If only the cheap airline company had spent a few dollar more on parachutes these poor doomed people would have had a way to save themselves.
I guess it makes for a nice story but it's not true. Airplanes don't fall out of the clear blue sky.
Almost all commercial air crashes happen within the first two minutes of taking off or landing . Ignoring all other reasons for not having parachutes on A/C , High speed and low altitude is the absolute worst environment for using a parachute.

Answer 3

Interesting question and one I hadn't thought of. After some thought I imagine a situation where there is an in flight emergency and there are three hundred or so passengers on a plane. People screaming and crying and trying to put on parachutes and the tiny isles are jammed with people and their parachutes some too scared to jump, hysterical women, children, people trying to climb over the hesitant ones to get to the door. Not a pleasant scenerio. I suppose the idea of parachutes for everyone was ruled out long ago for these same reasons.

Answer 4

Parachute jumping from a commercial airliner is not practical or even possible in most cases. Jumping above 10,000 ft. would lead to hypoxia and/or thermal exposure. The speed would need to be less than about 150 MPH. The parachute harness is relatively complex for a beginner to put on and adjust properly. On most airliners the doors cannot be opened when the cabin is pressurized.

The exception of course was the rear ramp door on the Boeing 727 that D.B. Cooper used when he hijacked the aircraft for ransom. He had the pilot descend to under 10,000 feet and slow to 150 MPH before he parachuted from the airplane, and it's still a subject of controversy as to whether or not he survived the jump.

The seat cushions on most airliners now double as "flotation devices" which means less equipment to carry, but still offers individual passenger bouyancy in the event of a water landing.

Answer 5

I agree with Scottish Soldier, in that the fitting of them would be problematic, but to me, the biggest drama would be the speed and altitude of the plane.

Your average sport jumps are from 10 or 15 thousand feet. Planes are much higher than that when cruising, at least double. The air temperature would be close to freezing too.

Then you have to consider jumping from a plane that is moving at over 600kph (or way faster if you are plummeting to the ground!). The shock to the body of such an exit would be a real drama for your average passenger and most likely knock you out.

The last thing that comes to mind is the time it would take to get 200-300 people (on a large trans Atlantic passenger jet) to an exit and out safely...considering they would have to use the exits behind the wing to avoid the distressing sight of passengers being sucked through the turbines....

Answer 6

The dorrs aren't designed to be opened in flight, the doors aren't designed to be exited in flight, and you stand a better chance of surviving a water landing than you do a skydive into water. Can you imagine the search requirements needed to recover 200+ people scattered out over the literally hundreds of miles of water the plane would cover while everyone got out? At cruise, a typical airliner covers about 100 miles every 14 minutes. Even if the pilot slowed to just above stall, you would still cover almost three miles a minute. How long would it take to make sure everyone had their harness on right, and knew what to do on exit? The Coast Guard would lose their minds.

Answer 7

No you shouldn't be an engineer. plane gas is such as diesel gas, that's rather not straightforward to ignite, it would not basically randomly explode. If it did not burn at the same time as compressed and heated jet engines would not artwork. commercial plane crashes are so uncommon that any type of pricy and complicated "protection function" isn't worth it. there's a really particular problem the position this can be sensible, understanding of gas or engine failure, which at the same time as that occurs pilots are able to worst case crash land the plane and its superb. in case you open a parachute at cruising speeds for most planes it may rip it aside and kill the occupants. What in the international do you recommend by ability of non electric powered button? Do you recommend a lever or some thing hydraulic?

Answer 8

A parachutist cannot exit an aircraft at any speed faster than about 80 knots without severe damage to him (her)self.
Commercial airliners travel at speeds in excess of 300 knots. Anyone trying to exit a plane flying at that speed would have their parachute torn to shreds immediately on exit, to say nothing of their body . The life jackets are there for those people who survive an aircraft crashing into the sea. At the very worst, floating bodies would be recoverable. I tend to think that inflating the life jacket just before impact might give you the same protection as an air bag in a car. Maybe, but they land normally at speeds over 100 knots.

Answer 9

As a skydiver I would assume that the altitude commercial jets fly in is incompatible with skydiving.

The air is too thin and the temperature is below zero at any altitude above 15,000 feet. Commercial Jets fly at two and three times that altitude and anyone who evacuated an airplane at that altitude would pass out due to lack of oxygen and also freeze to death before falling to a livable altitude.

A person in free fall falls approxiamtely 1000 feet in 5 seconds. At 37,000 feet a person would fall for 85 seconds in freefall before even reaching 15000 feet and the person would passout or perhaps even die in that amount of time and that would be even a healthy person.

Also a commercial plane travels too fast to be outside of it. The wind pressure would very likely break and perhaps even tear off arms and legs. The big jets can't stall to slow their speed or they will drop like a rock. Parachutes wouldn't do anyone any good.

Answer 10

It takes quite a bit of training to learn how to use a parachute properly. Especialy a free fall chute. Also if a plane is going down you probably will be to low to the ground to get eveyone out of the plane and still have time to deploy your chute. Most people would be to scared anyway to jump out of the plane even thought the plane is going to crash. There isn't really a one size fits all parachute harness either and you probably wouldn't have enough time to get it on and safely jump out the door.