Aviation safety plane crash question/idea

[girts]

So you know I've been wanting to ask this question for some time now.
Everytime you hear about an aviation disaster it is usually a plane that has had some trouble either with technical stuff or less often due to pilot error or otherwise, but what I want to say with that is that a big commercial jetliner never falls out of the sky like a rock but usually loses altitude gradually over some period of time after everything fails like in the worst scenarios where all engines fail and maybe even the system that control the aircraft's flying position.
Now surely there are sometimes moments like terrorist attacks or a plane being shot down by a missile like the recent Malaysian jet over Ukraine using the Russian Buk surface to air missile, in those situation my idea would not work because the plane and its fuselage is damaged and blow to pieces and it then falls almost like a rock in free fall.

So the idea is this, in normal technical problem situations where the plane descends as it loses power or maneuverability, why can't we equip every passenger with a parachute that has also special vest built in so that the person wearing it could float above water and not sink, as many flights cross oceans and large volumes of water where in the case of the plane falling help is far away.
So the question that rose to my mind while watching plane documentaries and disaster ones is this. Now at the cruising altitude of modern jetliners it would be impossible to open the doors due to the difference in air pressure and lack of oxygen but as the plane descends to lower altitude , something like 3/4 km it becomes perfectly fine to open the doors and the passengers could just jump for their lives.
Now normally when a plane falls there are almost never any survivors because the speed of impact is so large than both the plane and the people within get killed instantly so I think that jumping while the plane is still descending would have 90% or so higher chances of surviving.
What do you think why hasn't this been done given how relatively simply it is and inexpensive?

 

[sophiecentaur]

That escape method is used by the military but they do not use it for more than a very few crew numbers. I would bet they don't use it for military transport. It's basically not practical to get hundreds of passengers out of the plane, two at a time during the short time window (a couple of minutes, perhaps) between having a low enough airspeed and altitude and, say 100m minimum opening height. Parachute escape routine is something that needs to be practiced first and the general public can't even use escape chutes reliably. Many passengers couldn't even be relied on to put the parachute on properly.
It is April 1st today?
"inexpensive"? Litigation over how the escape had been managed and the resulting fate of each passenger would be unbelievably costly and suitable parachutes would be bulky and need expensive checking very regularly.

 

[girts]

No sophie not a yoke this time, Ii thought this for real.

Well you say that litigation and court cases for some passengers etc, but remember the other option is to sit and die, hopefully instantly sometimes a longer painful death with "fire and fury"...
Well if you ask me if I would be in a situation where a plane is surely about to crash and the pilots realize that I would be the first to try jumping with a parachute instead of sitting and waiting for my death.
Now normally maybe people would be a bit slow and afraid to jump and hesitate but I think in a case of real danger and emergency people would do it rather quickly with maybe some exceptions, because the basic instinct to survive is in there in all of us and given a chance where the hopes of surviving is like 100 to zero you really think people wouldn't use that chance as quickly as possible?I personally would feel much safer in a plane if I had a parachute and if I would know that in case things go badly wrong I can just run for the door.
After all for those who love danger and have done jumping before it would maybe even be a delightful experience.Why would it be costly? I just did a quick google search and it seems that an average sports parachute costs somewhere between 2k and 8k dollars, now imagine having say a 5k usd parachute for each passenger and crew member in a plane, still in case if the plane falls and everyone dies and it is determined that it was a technical fault or even worse the company neglect there are millions of dollars in court settlements for the relatives of the perished folks not to mentioned the grief and loss of trust and company reputation. I think such an investment if technically feasible would outweigh the cost.
Just look at Malaysian airlines, in one year two of their planes were destroyed with all passengers, and one case wasn't even their fault (Ukraine rebels shot it down) the second is still missing without any clue. The Malaysian government had to buy the company because it was literally destroyed.Well anyways back to the point, I was thinking is it really that hard technically? I am no aviation expert but I think the time window where the doors of the plane can be safely opened and there is enough oxygen to the point where the plane is too low for the jumping to be effective is rather large or significant enough in order for all the passengers to flee the craft.

I can't find any exact numbers and I think it is largely down to each individual case but say the pilots remain at the controls and can level out the plane, how long such a descent would continue in others words can someone tell how long is the time window that the people have for jumping given a classical "ran out of fuel" type of situation where the plane isn't physically damaged and the pilots have at least some control over the craft?thanks.

 

[A.T.]

So the idea is this, in normal technical problem situations where the plane descends as it loses power or maneuverability, why can't we equip every passenger with a parachute that has also special vest built in so that the person wearing it could float above water and not sink, as many flights cross oceans and large volumes of water where in the case of the plane falling help is far away.

It would probability be more practical to equip the whole airliner with huge parachutes and inflatable airbags for impact and floating.

 

[russ_watters]

So you know I've been wanting to ask this question for some time now.
Everytime you hear about an aviation disaster it is usually a plane that has had some trouble either with technical stuff or less often due to pilot error or otherwise, but what I want to say with that is that a big commercial jetliner never falls out of the sky like a rock but usually loses altitude gradually over some period of time after everything fails like in the worst scenarios where all engines fail and maybe even the system that control the aircraft's flying position...

So the idea is this, in normal technical problem situations where the plane descends as it loses power or maneuverability, why can't we equip every passenger with a parachute that has also special vest built in so that the person wearing it could float above water and not sink, as many flights cross oceans and large volumes of water where in the case of the plane falling help is far away.

What do you think why hasn't this been done given how relatively simply it is and inexpensive?

The main reason is that there aren't actually all that many scenarios where it would work. The plane would have to be traveling slowly, level, low enough, high enough, leave enough time to put on the parachute and evacuate, and the pilot has to know the situation is not recoverable - while still being able to control the plane. Meeting all of those conditions at once would be extremely rare.

You should peruse crash reports and see if you can identify any where a parachute would help.
https://en.wikipedia.org/wiki/List_of_accidents_and_incidents_involving_commercial_aircraft

Off the top of my head, I can only think of two crashes where such conditions were met, both having roughly the same cause, and both unlikely to happen again. They were loss of hydraulics incidents where the pilots were able to control the planes for many minutes using the throttles. In the Soux City Iowa crash, the pilots almost landed successfully and half the passengers survived.

 

[russ_watters]

It would probability be more practical to equip the whole airliner with huge parachutes and inflatable airbags for impact and floating.

And indeed, some small planes have parachutes, though I question the usefulness for them as well...

 

[davenn]

Now at the cruising altitude of modern jetliners it would be impossible to open the doors due to the difference in air pressure and lack of oxygen but as the plane descends to lower altitude , something like 3/4 km it becomes perfectly fine to open the doors and the passengers could just jump for their lives.

you haven't even taken into account the high speed of the aircraft and the improbability of being able to exit the aircraft without sustaining injury with an outside airspeed of 400km/h or more

Just look at Malaysian airlines, in one year two of their planes were destroyed with all passengers, and one case wasn't even their fault (Ukraine rebels shot it down) the second is still missing without any clue.

and no one would have survived the first one anyway, parachute or not with the aircraft exploding in mid-air because of the missile strike
If the aircraft didn't completely breakup, say, just a wing was hit and broke off, the aircraft is likely to go into an uncontrollable steep dive and you are not even going to make it to a door because of the wild gyrations/spinning as it plunges to the ground

maybe you didn't know some wreckage has been found for the other Malaysian flight? Why the plane went down is still unknown ( well at least publically)

 

[sophiecentaur]

I would be the first to try jumping with a parachute

Which exit would you use and what would you do about the other hundred people trying to get to it? How fast did it take you, last time you exited a plane after a panic - free landing? Could you imagine the fighting for the exit (after people had fought to fit their parachutes themselves, for the first time, in the aisles)?
At a stall speed of over 100mph, what sort of exit could you achieve? Then where would you land? Trees, mountain sides, the sea are mostly not easy to land on and get away from - even for an action man such as yourself.

 

[Vanadium 50]

You should peruse crash reports

This. Indeed, this is the first thing you should have done.

Let's look at fatalities of the ten deadliest commercial accidents:

• Tenerife (1977) - on the ground, wouldn't have helped
• JAL 123 (1985) - possibly would have saved a few - however many of the 520 passengers and crew could have exited an out of control aircraft in 32 minutes. Note that even using all 32 minutes, evacuating everyone requires 4 second separation. (!)
  
• TK 981 (1974) - would not have helped, crash was ~3 minutes after the failure
• Charkhi Dadri (1996) - mid-air collision, both planes out of control, wouldn't have helped
• AI 182 (1985) - plane destroyed by bomb, mid-air, wouldn't have helped
• Saudia 163 (1990) - plane landed safely, then burst into flames, wouldn't have helped
• MH17 (2014) - plane shot down, wouldn't have helped
• IR655 (1988) - plane shot down, wouldn't have helped
• AA191 (1979) - engine-out climb, wouldn't have helped
• AA587 (2001) - crash 45 seconds after failure, wouldn't have helped

Furthermore, parachutes take up a lot of space. That means less room for passengers, which in turn means more flights. That increases the risk. I think this plan is likely to kill more than it saves.

 

[anorlunda]

I'm with @russ_watters on this one. Better to equip the plane than the passengers. Here's a news item about ballistic parachutes. They say 30000 aircraft already have this device.



Without training in advance it would be a horror scene trying to get all those people to jump. Some would want to take their luggage. Some would refuse to jump. Some would pull the rip cord while still in the plane. People who parachute into cold water or tall trees suffer a horrible death. Then there is the horror and liability if some passengers die jumping out but eventually the plane lands safely after all.

The chances for survival are best if the pilots try to land. Any airplane that is able to glide with wings level to allow people to jump, also has a chance of landing safely.

Study the Gimli Glider incident as an example. This video is only 7.5 minutes, but there are 90 minute videos of this incident on Youtube.

 

[girts]

well to be honest, I kind of overstated my idea just to get a clear objection to it but I really did not think myself that this could be a viable safety alternative because of all the previously mentioned complications.
I would have to agree especially after what some of you said here that indeed equipping the whole airplane with a parachute is a more realistic idea, I see the example already done for small planes and I assume it is easy for small planes due to the low weight of the plane so the parachute size is not that big and can be fitted rather easily.

I wonder can they equip large commercial size jets with such safety alternatives, because for a small size plane one might as well have individual parachutes for each aboard as well as a plane size one for the whole plane.
still say they could equip jetliners with an emergency parachute that at least slows down the plane to the point where the speed is not life threatening upon impact, together with say fuel dumping and other means of reducing the weight and flammability of the craft if it falls down.

Now I don't have any numbers for this but just as an idea, how about parallel to having a parachute to a jetliner, there would be some emergency ways in which ne can lose weight in the case if the parachute needs to be deployed ? apart from dumping any remaining fuel is there anything else a jet can lose that doesn't directly affect it's rate of descent versus it's weight ? because after all the effectiveness of the parachute is largely dependent on the weight of plane and it's aerodynamics.maybe a silly idea but still, since some 70% of Earth's surface is covered with water that means most international flights fly over oceans most of the time, which means that if something goes wrong it is far likely the plane will land on water than land, now having each individual wear a lifevest or something is probably again rather expensive and complicated, but how about since the plane is already rather light (made from light alloys such as aluminum etc) and has a lot of empty space inbetween the structural parts of the fuselage, how about equipping he whole fuselage with many individual pressurized air compartments made of say special rubber or something, in other words having the fuselage filled with balloons, would it realistically be possible that such air pockets all around the plane with pressurized air inside them could keep the plane afloat in case it somewhat safely lands on the ocean surface?
atleast such air pockets wouldn't add any large amount of weight to the plane.
PS. yes davenn I am well aware that they found a few pieces of the missing plane but those pieces provide no actual evidence nor explanation for what happened to the plane, as well as I am aware that any safety features installed in future planes wouldn't safeguard against cases where the plane is deliberately blown up and cut to pieces like in the case of MH17 and the old soviet BUK surface to air missile.

 

[sophiecentaur]

We should remember that air travel is very safe compared with most other forms. The rates of deaths per hour / mile / passenger etc. etc. are all pretty competitive. Spending more on education and supervision of car drivers would have a much greater effect on life span but we really aren't too bothered when we drive past an obviously fatal accident site. There may be a bit of a fuss if a victim of a traffic accident is a child but the reaction overall is pretty stolid.
Humans are strange creatures.

It's interesting that the Gimli glider incident was due to a mundane thing like staff training and education. It's amazing that the plane didn't 'know' there was not enough fuel. Perhaps modern craft would know.

 

[Vanadium 50]

It would probability be more practical to equip the whole airliner with huge parachutes

I don't think that will work at scale. An A380 weighs almost 600 tons, about 400x what those tiny planes weigh. What kind of parachute do you need? What do the lines and risers need to be made of? And that's just looking at the vertical - in the horizontal you have the problem that it's still 400x bigger, but 3x faster so you have to shed more than 3000x the kinetic energy.

 

[girts]

well sure aviation overall is among the safest means of transportation right next to trains I assume, good point about the fuel gauges, it seems rather strange given that every car even the old ones have a simple gauge that shows you how much fuel is in the tank yet the plane as written in wikipedia had it's fuel amount put in the computer as full and then the computer calculates the amount of fuel left based on various inputs like airspeed, engine factors etc , at least if I got that information correctly, seems odd that it wouldn't have a gauge that is not digital but rather analog that simply shows the approximate amount of fuel in case everything else breaks or loses electricity.another point to take home is that they put less fuel in because they had recently switched from imperial to metric unit system which then caused mainly this misunderstanding. and as far as I remember there have been other notoriously expensive and dangerous mishaps simply because of the rather stupid fact that different people feel differently and sometimes even proudly about their own way of measuring things instead of accepting one universal way of doing it and by that making life easier and safer all around the globe.

anyway I would much appreciate any input on my previous post and it's content.

 

[sophiecentaur]

the plane as written in wikipedia had it's fuel amount put in the computer as full

If the figure put into the computer was from ground staff who wrote it in the wrong units then the poor old processor only would have had that to go on. I would bet that the people who got disciplined were not the ones basically at fault. 'Someone' failed to drill it into them that pints / gallons / litres are different and that may have been ignored when handing our the slaps afterwards. Also, you would have thought that the flight crew would have been aware that they were operating a new units regime and would have done their own independent calculations, relating the position of the 'needle' on their meter with the distance they were planning to travel. But I believe arriving with a lot of surplus fuel is frowned on - especially if the destination fuel costs are cheaper than where it was bought. No one wants to fly around with a full tank unless they are going to Australia (pick your own destination for that one).

 

[girts]

Vanadium has a valid point, any small plane is nothing compared to the typical commercial jetliners like the classic Boeing 747 or 737/767 or Airbus A320/380 or others.

Well this is probably a unrealistic idea simply due to technical and financial reasons but maybe the large planes could be made such that they have an inner hull that is lightweight and fragile mounted inside the fuselage together with the emergency parachutes attached to it, and in the case where pilots determine that due to some technical error the plane is definitely going to crash they could activate a system that somehow gets rid of all the extra weight which would be unnecessary if the plane can't make a normal landing but instead has to use parachutes to land, heavy things like the undercarriage and it's support struts and beams, fuel tanks, maybe even whole wing sections and parts of the fuselage, because if you have to descend using a parachute the wings and their aerodynamic control don't matter much anymore right? In other words the idea is to lose everything that has weight and is of no use for the main goal of saving the people on board. Such a light hull could maybe also be light and big enough to essentially float above water.

I assume that the mentioned weight for the Airbus380 which is I believe the largest jetliner in use today is together with its full fuel tank capacity?
anyway I wonder how heavy it is if the fuel tanks and wings and engines and landing gear is removed, simply say the passenger fuselage is only kept.
I guess you could also lose airspeed quickly if you got rid of many of the heavier parts that would decrease the inertia of the remaining plane.Also I wonder woudln't the planes of tomorrow eventually becomes much lighter with new materials like carbon fiber and all kinds of alloys and carbon-nanotubes , even though I assume we still can't make the last ones on large amounts.

anyway just my two cents of imagination.

 

[sophiecentaur]

simply say the passenger fuselage is only kept.

Two big problems.
1. The cost of the sort of (pyrotechnic) mechanism that would be needed. Engines etc would all have to be ejected at precisely the same instant on both sides and the remaining pod would need some careful trimming to avoid tumbling / spinning. More checks would be needed every flight. You could possibly double the air fares for all that.
2. What sort of seating and restraints would be needed to make sure that no passengers were thrown about the cabin during all this happening?

I feel that the thread is nudging the fringes of lunacy. (Nothing wrong with that in principle but we should acknowledge it. )

 

[Nugatory]

now having each individual wear a lifevest or something is probably again rather expensive and complicated

There's already a lifevest under your seat on overwater flights. On many aircraft the inflatable escape slides at the doors function as rafts when deployed in the water.

 

[anorlunda]

I'm afraid that it's true. This thread is too far removed from reality.

@girts, I recommend that you view several of the Air Crash Investigation episodes on Youtube to get a better idea of what is and is not practical.

This thread is closed.