Giant Parachute For Planes

[Monkeymagic99]

We have huge parachutes for space shuttle rockets and for returning astronauts.

Would it not be a viable idea to have huge chutes on planes for when engines malfunction etc?

[waterboatman]

Space shuttles are a lot smaller than 747s

[Monkeymagic99]

Is it a weight issue?

[1ozzy]

Round two begins, ladies and gentlemen please return to your seats.

[rowanwitch]

In a word. No. But because they would need to be so massive and the fabric volume alone would make it impossible. Let alone the effects of trying to deploy a huge backward and upward force on what is basically a very lightweight and flimsy structure relative to size.

[Monkeymagic99]

That doesn’t seem to be a problem for shuttle rockets or rentry modules.

[rowanwitch]

They are smaller, lighter but incredibly strong because they are designed to cope with immense forces. As well as extreme heat the do however use the friction with the eat the atmosphere to slow slightly so the chutes are deployed below terminal velocity

[Monkeymagic99]

There just has to be a way of saving a plane and lives in case of catastrophic engine failure etc... instead of just resigning everyone to death.

[Old_Geezer]

Or, they could fit a trampoline on the aircraft's nose.

[derek-33]

i cant recall any passenger aircraft that has "crashed " due to complete engine failure, dont forget a two engined aircraft can safely fly on one and a four engined can do so on two.
yes the 747 in the volcano eruption years ago lost all four but that was due to ash in the air and they did restart and land safely but that was a unique event

[spathiphyllum]

Not to mention drag cars

[spathiphyllum]

http://markjrebilas.com/blog3/wp-content/uploads/2010/10/ea10Z_3508.jpg

[mushroom25]

//i cant recall any passenger aircraft that has "crashed " due to complete engine failure//

the "Gimli Glider" springs to mind - but that was due to fuel starvation......

[spathiphyllum]

Concord?

[spathiphyllum]

Concorde's crash was caused by the loss of the two engines on the left side of the aircraft

[IJKLM]

To Derek at 09.52, the Air France 447 in 2009 crashed because the pilot tried to raise the nose, sending the plane into a stall, and causing it to plunge, pancake-like, into the ocean.

https://en.wikipedia.org/wiki/Air_France_Flight_447

In theory, a parachute might have saved this, but not in practice.

First, the parachutes on the space shuttle, or fighter aircraft (especially as they touch down on sea-borne carriers) are intended to decelerate the aircraft as quickly as possible, after the craft has touched down on a runway.

They are not intended to prevent or mitigate a hard impact as the aircraft plunges from a considerable height.

It is true that he capsules containing astronauts (such as the Apollo missions), used parachutes to slow the impact, after the capsule had decelerated from supersonic speeds due to air friction. However, the capsules are relatively light and small and near-spherical in shape, in comparison to a large passenger aircraft.

Trying to arrange parachutes on a passenger aircraft that would keep the thing horizontal as it dropped would need (at least) three 'chutes arranged around the wings and the tail; they would need to be balanced for size. Not an impossible task, but not trivial.

And then what happens when the thing hits the ground? The impact speed would be enough to kill most of the occupants, ubless the 'chutes were impracticably large. In the case of AF 447 (above) the impact speed crushed almost everything on board, as it hit the ocean surface pancake-like. "The airliner was likely to have struck the surface of the sea in a normal flight attitude, with a high rate of descent"

In addition to the challenges of achieving a survivable ground-impact speed, I guess the main reason is that when aeroplanes are up in the air, they almost always have a large forward velocity (around 500 mph). If the 'chutes were deployed (by accident, for example) during normal flight, first, the windspeed would probably destroy the 'chutes and second the rapid reduction in forward speed would probably cause the aircraft to fall out of the sky, with no certainty that the 'chutes would remain effective as the relative wind-direction changed rapidly from near-horizontal to near-vertical (even if they remained undamaged due to the forward motion of the aircraft).

In short, a chute that is big enough to slow the dropping aircraft down to a survivable impact speed and also strong enough to withstand a 500mph-plus forward wind speed during deployment would be impractical.

Having said all that, flying remains he safest form of travel, so I wouldn't worry about it :)

[Togo]

Wouldn't it be easier to have a giant airbag? Sort of like a bouncy castle underneath. :))

[derek-33]

IJKLM
we are talking about engine failure not pilot incompetence as was the air france crash

[derek-33]

spathiphyllum
actually concords engines did not fail one was shut down as they thought one as on fire hence it lost power to gain height, as it was that accident was inevitable with that damage

[steg]

This may be interesting to you

http://www.bbc.com/future/story/20131223-should-planes-have-parachutes

[Zacs-Master]

Just a point but concord was only about 12 feet off the ground when the engines failed (due to a burst tyre, I believe), I don't think a parachute would have helped in that situation.