Why don’t commercial airliners install emergency parachutes underneath each seat in case an unfixable problem occurs at 30 000 feet?
Suppose you have the chute… how do you get out? How do 400 people get out FAST?
Not to mention that at 30000 feet you can´t breath…
The same reason that they don’t make passengers wear a 5 point harness and helmut. Very high cost for minimal benifit.
The vast majority of aircraft accidents just don’t accur up at 30,000’. Most accidents involve a few seconds of surprise as the pilots realise something is wrong and then they hit the ground. In fact many accidents involve the aircraft hitting the ground before anyone realises something is wrong.
Just what do you think is going to happen at 30,000’ other than running out of fuel?
Because if “something happens” at 30,000 feet, it’s unlikely the plane’ll be controllable enough to aim for the kind of slow, straight-and-level flight that you need to jump out without an ejection seat?
Aside from inability to breathe, how do you manage to avoid getting your chute knotted up with the hundreds of other chutes being deployed at the same time and same place?
Not to mention, it is -60 degrees outside, and you’re moving at 500 mph. You wouldnt survive more than a matter of seconds without a pressurized oxygen delivery system and thermal suit all built into the seat, and in use the instant you eject.
A Cirrus SR20 and 22, a 4 seater single engine aircraft, has a parachute that you can deploy in an emergency. The best feature is that Cirrus will replace the aircraft if you should need to deploy the chute because of a manufacturer malfunction.
Yeah, sure… try pulling that trick on a 747. 
400 rocket propelled ejection seats.
With little oxygen bags that pop out, but don’t inflate.
If the system ever seployed successfully, it’d make an awesome sight!
There would have to be some significant redesign of the airplane to allow a door or hatch to be safely opened during flight to allow people to jump out. As well, a serious problem which cannot be handled by the pilots well enough to land the airplane is almost always going to be such that there would be very little chance for anyone to be able to get out. The plane would need to be going fairly slowly and in more or less straight and level flight at low altitude for untrained passengers to be able to exit without hitting some part of the plane, being immobilized by acceleration/centrifugal forces, frozen/asphyxiated or otherwise unable to safely exit.
In most cases, if the pilots can control the plane well enough for a safe parachute exit, the passengers would be at less risk in an emergency landing. This is assuming that there is even time for everyone to react, find and correctly put on the parachutes, and line up to jump out, as modern airliner accidents tend to be minor enough to allow at least an attempt at landing, or to be suddenly catastrophic with the plane almost immediately breaking up or becoming uncontrollable. The majority of fatal accidents also happen on takeoff or landing, when the plane is too low and things are happening too fast for parachutes to even be an option.
One of the reasons why military combat aircraft have ejection seats is that they are the only way to guarantee that the pilot and crew will have a reasonable chance to escape when the plane is fast/low/uncontrollable. For “non-combat” aircraft (recognizing that any military aircraft in a war zone may be shot at), there is a very realistic view of the chances of sucessfully parachuting from a stricken aircraft, and there normally aren’t any parachutes carried. (I believe that loadmasters - the guys who stand by the back ramp and control the drop of cargo and paratroopers from tactical transports like the Hercules - do wear them in case they fall out of the open ramp by accident.)
This spawns an ancillary question: did they ever provide passenger parachutes on commercial air? Not anytime recently, but back in the wilder and woolier early days.
Ignoring all other factors (good ones), there’s a basic one that’s being overlooked.
It takes training to learn to use a parachute. You have to take lessons and learn what you’re doing. Otherwise you run the risk of being hurt very badly when you reach the ground. The amount of time and money it would take for either you or the airline to make sure that you’re qualified to do it would be unreal.
And what about passengers who aren’t physically up for a jump? I’m thinking of my 82-year-old grandma who just had heart surgery. She’ll be flying to Hawaii in a few months. There’s no way she could jump. Trust me.
Last week I returned to the US from London via a 777 (the kind of plane where everyone has an individual screen on the seatback in front of them?) Anyway, during most of the flight, the inflight information screen said the outside temperature was between -60 and -90F outside. That’s enough to kill you itself, not taking the lack of O2 into account.
To learn the sport of parachuting takes lessons. To be capable of an emergency jump, it’s generally sufficient to say, “This here is the ripcord handle. Get out of the aircraft, look at the handle, and pull it.”
In other words, if you know you’re going to be using it, it makes lots of sense to get training. If it’s simply a case of might possibly use it, you tend to skimp on the training and trust in the fact that parachutes are very reliable.
You are correct that the landing can be dangerous - sprained and broken ankles are not uncommon on emergency jumps. The jumpers don’t seem to be troubled as much as you might think by these injuries - they tend to be thinking that they are rather lucky.
This question comes up every couple of years, it seems. I know there are at least two threads on it, but I’m being lazy tonight. (Slow connection, been creating web pages, etc.)
Basically, providing parachutes to untrained passengers wouldn’t work. Whole-plane recovery systems for aircraft the size of airliners wouldn’t work. And so on.
I believe it’s pretty routine for highly trained, in great shape pilots to break various limbs when they eject. Now imagine the liability involved in 400 untrained souls hurting themselves when they rocket out of a 747.
Considering that if a plane were about to crash, I’d take my chances learning to use a chute on the way down…
Wouldn’t you have to blow the top off of the plane in order to get 400 seats to safely eject?
How could you possibly hold the plane together long enough for ejection to be effective.
Plus, as was stated, low O2, lack of air pressure, low temps…
Be happy your seat doubles as a flotation device.
Actually, all things considered, it’d probably be easier and more effective to install ejection seats in automobiles. The roof would be easier to blow out of the way, you wouldn’t have to worry about air pressure or low temperatures, and you’d be more likely to need it in a car than an airliner. (More car accidents than airliner accidents.)
Of course, you’d have your problems, too. For starters, the driver couldn’t control the ejection himself…too much room for error or accidental deployment, not to mention the fact that an average driver’s reaction time probably wouldn’t be fast enough to save himself in an emergency. You’d have to have it controled automatically, like an airbag. And even then, you run into problems…like, if you get in an accident while you’re in a tunnel, or if the car has flipped on it’s side before the seat is triggered. Or if the driver, not expecting to be suddenly ejected, hasn’t tucked his arms and legs in…meaning they might get broken (or torn off) as the seat deploys. Not to mention what would happen to the other passengers in the car, who get left in a crashing vehicle that’s had a rocket motor burn it’s way out of. (Unless you give everyone ejection seats…in which case you have four or more ejections taking place simultaneously, less than a foot or two away from each other.)
I’m sorry, I think I’ve forgotten the original question.
That’s true. Even a trained agent never uses the car ejection seat properly [/Get Smart, Agent 86]
Let’s see if I can sum up the major objections to what, initially, seems a very good idea - parachutes for airliners at 30,000 feet:
First, how do you get out of the airplane?
Airplane doors are designed to be held shut not just by mechanical locks but also by the air pressure inside the cabin. There are literally tons of force holding those doors closed. The only way to open those doors is to equalize the pressure between the inside and the outside (see “surviving the environment outside”). This will take time, unless the airplane is already breaking apart. In which case you will not need to open the doors to get out.
But, assuming you are using the doors, you now have the problem of ushering scared/terrified/panicked people out of those doors in an efficient manner. I think the odds of pushing and shoving are quite high. Not to mention that, once the doors are open and the pressure equalized you will have cold scared passengers, struggling with the 'chute and oxygen tank. If they don’t have portable oxygen they’ll be unconciousess. I suppose you could have the flight crew drag the passngers to the door, shove them out, and rely on automatic canopy deployment devices to open the chute at an appropriate altitude, but that will take considerable time.
Second, how do you survive the environment outside?
Baby, it’s cold outside. VERY cold. As someone has already noted, -60 to -90 F is normal. You will also have to contend with that wind - the airplane is going to be going plenty fast. However, let’s assume the airplane is able to slow down (already we’re slanting this heavily in favor of survival here - in a real accident you may be going at any of many very fast speeds). A jet is not going to slow much below 200 mph true airspeed. As soon as you reach the door you will be contending with a 200 mph breeze, temperatures of the Antartic winter during a cold snap, and a windchill that would make dry ice look warm in comparison. And, oh yes, not enough air.
OK, you step outside. Be careful not to get slammed against the fuselage, wings, or tail of the airplane - not that you have any control over where you’re going - because the impact may break or tear off limbs, or just be outright fatal. Don’t get sucked into a jet intake. Without protective gear, you’ll get some very nasty windburn and probably frostbite within minutes, if not seconds. But that’s a minor problem, really.
You see, there’s not enough air. Without an oxygen supply you won’t be concious long enough to get this far, but even with 100% oxygen to breathe you are still in deep doo-doo. The human respiratory system relies on pressure differentials to help drive air into the lungs, and then to exchange gasses across the cell barriers. At 30,000 feet there’s not enough pressure to make the system work effectively, or perhaps at all. Folks who climb Mt. Everest are in great physical shape, spend weeks aclimatizing, and many of them never reach the top because they’re stopped by such maladies as pulmonary and cerebral edema, strokes, and heart attacks. You will not have weeks to acclimatize to this altitude. I’m currently reading a book by Kenneth Kamler (Surviving the Extremes) who has become an authority on medicine in extreme environments. He was wathcing a helicoptor rescue from Everest in 1996 and feeling dread because, if the pilot couldn’t lift off the mountain he didn’t think he could keep the pilot alive more than a few hours - the pilot wasn’t acclimatized, and he would die before he body could adjust, even with 100% oxygen and a full supply of medications to alleviate the worst symptoms. In our hypothetical airplane emergency you’d be at least a mile higher and without medical care.
So… even with 100% oxygen you’d probably suffer from some visual effects like tunneling of your vision. Your brain will also be starved for oxygen, which means your thinking will be flawed. Your muscles will be starved for oxygen - you won’t be as strong and you won’t react as quickly as you would at sea level. And that’s assuming you’re physically fit. The frail or those with cardiovascular problems might simply die, or perhaps “just” suffer some brain damage. Diminished judgement, strength, and reaction times are bad things in a life-or-death emergency.
Wait! We’re not done yet! You might also be suffering from the bends. Yes, you might. The bends are triggered by a sudden drop of pressure, and people have suffered the bends in high altitude flight when the pressure was abruptly reduced and the nitrogen they absorbed breathing at sea level came out of solution and started to really mess up their bodies. Basically, your blood gets fizzy like a shook up bottle of carbonated soda. People have suffered mild symptoms of the bends as low as 20,000 feet in unpressurized aircraft - you’re two miles higher. The bends cause horrible agony, and can cause direct nerve damage to both peripheral and central nerves. Your joints won’t work properly, and you may lose feeling in your limbs. Your vision and hearing will also be affected. The bends can also cause heart attacks or strokes Anyone who has been scuba-diving in Maui will be particularly hard hit - every year the airlines have to deal with tourists who are suffering from the bends at normal cabin pressures. Fortunately, these cases are typically not severe enough to kill, but they can cause prolonged hospital stays. When they say leave at least 24 hours between diving and flying they mean it - better to leave 2-3 days.
Therefore, at best you will be half-concious with stiff, weak, half frozen limbs and plummeting towards the ground at 120+ mph. In this state you will have to locate, grip, and pull a ripcord. Do you even know what a ripcord looks like? I don’t. I just know it’s a thingy you pull to make the parachute open, I couldn’t draw or describe what it looks like, though. Which bit on the harness is the correct bit to pull? It would take me some time to figue it out on the ground when I’m warm, well-oxygenated, and under no pressure - free-falling half concious in panic mode will not make this puzzle easier to solve.
A lot of folks, of course, will be worse off than the best case due to pre-accident physical condition, panic, injuries suffered prior to airplane exit, and so forth.
This is all assuming good weather - if you’re jumping out in a thunderstorm, well, things can get even more exiciting. There was an air force pilot who ejected above a thunderstorm and fell through it. The air currents didn’t let him down for over two hours. He rode up and down, up and down. Despite his g-suit and oxygen, by the end he had cold injuries and was bleeding from nose, mouth, eyes, and ears, and had suffered internal injuries from pressure changes. He survived and recovered, but we’re talking about a young man in excellent physical condition. In WWII there were some gruesome situations where people bailed out into storms and came down encased (and dead) in coccoons of ice over an inch thick - basically, they were turned into human hailstones. You could be struck by lightning. Rain could soak you to the skin and cause hypothermia. Those are just the problems I can think of off the top of my head, I’m sure there are others I haven’t thought of because I’m not an expert at this sort of thing.
Good luck. You will need it.
Third, how do you survive the landing?
As already mentioned, emergency jumps often result in broken ankles or legs. Given the alternative, most survivors do, indeed, view themselves as fortunate. We can assume in our hypothetical scenario that we will have the same - broken lower limbs. That’s assuming there’s even a place to land.
What if you’re over an ocean? Water jumps are hazardous, even for trained and experience jumpers. What if you’re over trees? You’ll probably survive hitting the top, but then how do you get down without getting killed? Particularly if you’ve already suffered injury in exiting the plane and on the trip down? What if you’re over mountains and there’s no flat landing space, or you come down on top of a mesa with sheer cliff walls and no way down without mountaineering equipment?
But let’s, just for the sake of argument, say you’re down and able to walk. There’s no gaurantee help is nearby, or even human habitation. You now have to stay alive until rescue arrives. You could be in a desert in the Australian Outback, in the middle of the Great Plains during a winter blizzard, on the Serengeti being eyed by hungry lions, or on an island in the Pacific. Urban areas aren’t safe, either - what if you landed on an American Interstate or the German Autobahn? Would be a shame to survive an emergency exit from 30,000 feet only to get nailed by a BMW in a traffic accident.
So, you see, the problem is not as easy as it looks. You have to deal not only with the problem of a truly serious in-flight emergency, but also an extremely hostile exterior environment, a dangerous trip of about 5 miles straight down, a potentially difficult (or even impossible) landing site, and perhaps even the problem of suriving with minimal or even no equipment until help arrives. This would be difficult even for the young, healthy, and prepared. Your average tourist is going to be in a world of hurt over this one.
Combine this with the fact that very few accidents occur in “cruise flight” - that’s the high altitude portion - and the cost way, way outweighs the benefits. Run out of fuel at 30,000 feet? It’s happened, more than once, and landings have been made safely by gliding them to the ground. Granted, this is not an experience I’d seek out but hundreds of people have survived this without injury. The vast majority of fatal airplane accidents happen too low for effective evacuation and parachute deployment, and happen too rapidly for much to be done. Better to spend the money building more reliable airplanes, and investing in maintenance and crew training to avoid problems, which is what has been done and has helped to make air travel exceedingly safe in comparison to other methods of transportation.
So, you’re saying it would be a bad thing?