Parachutes on planes.

T

TheFrogger

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Banned
Hi there.

I was told about an idea to fit planes with parachutes in case of emergencies. How possible is this? I think it's a good idea.
 
TheFrogger said:
I was told about an idea to fit planes with parachutes in case of emergencies. How possible is this? I think it's a good idea.
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Bad idea.

I recently did a study of air disasters. Of the thousands of crashes/fatalities over the decades, exactly one (JAL 123) would have benefited from having parachutes on board. And even then, survival would have been doubtful for the people using them. In fact, the presence of them may well inspire people towards fatal misadventures - increasing the fatality rate.
 
TheFrogger said:
Billvon, do you know why commercial jets don't already have them??
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A 777-300 weighs ~343,300 lbs, not including passengers and luggage. Traveling at several hundred mph. If the engines just quit it would still be going very, very fast. Just straight down.
 
TheFrogger said:
Emergency reserve engines??
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This is incredibly silly. Commercial aviation is already extremely safe, compared to all the risks we accept, daily, in our lives.

If one makes a list of the things to be done to improve the safety of our lives, this must rank at or near the bottom.
 
TheFrogger said:
Billvon, do you know why commercial jets don't already have them??
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Because:

1) The complexities of decelerating a million pound plane from 550 miles per hour safely without destroying the aircraft or pulping the people inside are formidable.
2) Even if you could do that, the challenge of designing a parachute that could soft-land an aircraft like that are equally daunting.
3) It is likely that the weight of that parachute would cause tradeoffs that would make aircraft even more dangerous (i.e. have to carry less fuel, have to reduce design margins.)
4) In most cases a parachute would not help. There are very, very few airliner accidents where pilots both knew that the situation was unrecoverable and decided that at a sufficient height to use a parachute (i.e. >3000 feet or so.)
 
Gawdzilla Sama said:
A 777-300 weighs ~343,300 lbs, not including passengers and luggage. Traveling at several hundred mph. If the engines just quit it would still be going very, very fast. Just straight down.
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Uh, no. Boeing 777 glide ratio is ~16:1. I believe ETOPS 180 qualified. That is why it is allowed to fly half-way around the world, much of it over water.
 
I am late to the thread and apologize. I agree that an entire commercial aircraft would be challenging (perhaps non-feasible) to parachute land. However, this thread reminds me of a Popular Science or Mechanics article back in the 80's. They speculated that a compartment jettison (with passengers inside) would be feasible by parachute. Obviously, the rest of the plane would be allowed to crash.

It was a long time ago. Perhaps more thought and effort has been put into the idea since then.
 
TabbyStar said:
I am late to the thread and apologize. I agree that an entire commercial aircraft would be challenging (perhaps non-feasible) to parachute land. However, this thread reminds me of a Popular Science or Mechanics article back in the 80's. They speculated that a compartment jettison (with passengers inside) would be feasible by parachute.
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Again, the problem there is that a pilot has to decide that the aircraft is unlandable at a sufficient height to activate the system. And he will have very powerful incentives to NOT use it if there is any doubt. I can think of perhaps five incidents in all of commercial aviation (since the 70's at least) where such a system might have helped.
 
billvon said:
Again, the problem there is that a pilot has to decide that the aircraft is unlandable at a sufficient height to activate the system. And he will have very powerful incentives to NOT use it if there is any doubt. I can think of perhaps five incidents in all of commercial aviation (since the 70's at least) where such a system might have helped.
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I read your reply twice...I need to do that sometimes so I get it right. What clicked in (the second time) was that pilot decision comment. It makes perfect sense. Super expensive aircraft...hasty, or premature decision, would be horrific. Especially if 156 compartment passengers jettisoned (presuming flight staff with them) and then the plane crashes into an elementary schoolyard:(:(:(.

Your explanations must be reasonable and accurate or else this technology would have advanced. After all it is almost 40 years since I read that article.
 
TheFrogger said:
Tabbystar, the idea is for parachutes FOR the plane. :)
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I understand. There are engineering challenges though. Apparently they have not been overcome or the idea is simply non-feasible. The compartment idea (that I read) was an alternative but it seems like it did not move forward (with valid reasons why in this thread).

I wish super high speed global bullet trains would become a reality. I even read about one concept under the ocean from U.K. to USA. I always get queezy from flying...even though accident rates are low from my understanding.
 
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