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If the Helium is compressed until SOLID , then contained with appropriate material , whenever there is a problem , the Helium is allowed to expand and fill a giant balloon , which could have the effect of
1- Increasing the Buoyancy , making it float longer and take a longer time to reach ground .
2- Cushion the fall .

So the question , is that possible , and why hasn't it been done yet ?

2007-07-18 15:22:30 · 11 answers · asked by proteusmirabilus 4 in Cars & Transportation Aircraft

John Paul , I would like to ask you this : what is the relation between my question and the sea ? I'll tell you : it's called BUOYANCY , it's why ships don't drop to the bottom of the sea and sink . Think of the atmosphere as a sea that is made of very light material . If you can get something that is "lighter" (less dense) then it will be "carried" by this sea of the atmosphere . That is how the Zeppellins worked .

2007-07-18 15:34:58 · update #1

Yes , the cost . But tell me , is there a cost too high for saving human lives ?

Of course the balloon would have to be made of special material , maybe some kind of super fiber-glass or Tefflon . And the balloon would have to be fastened to the fuselage , so it doesn't just fly away !!

2007-07-18 15:38:38 · update #2

11 answers

It is an INTERESTING idea... but as others have pointed out, highly impractical... weight, cost, helium storage & cooling, and the engineering of a "balloon system". NOT to mention that approximately 80 percent of all aviation accidents occur shortly before, after, or during takeoff or landing, when use of such a system wouldn't really matter.

First... let's use a 737-500 as our example with a takeoff weight of 133,210- 187,700 pounds:

The buoyancy for one liter of helium in air as:
0.1786 grams * (1 - (1.292 / 0.1786) ) = -1.113 grams

So a MINIMUM gross-weight 737 of 60,422.7 kilograms would require 68 million liters of helium to achieve neutral bouancy!! That is 12,000 kilograms of helium... or 26,000 pounds.

Also, as others have pointed out... you'd most likely be deploying a balloon between the aircraft's cruising speed of mach 0.77 (592 mph) and approach speed of 133 KIAS (153 mph)... the engineering required to deploy a system would be prohibitively expensive in cost and weight.

Just FYI, wthout any lifting gas, the empty Goodyear Blimp (GZ-20) weighs about 12,840 pounds

2007-07-19 04:34:49 · answer #1 · answered by mariner31 7 · 0 0

The majority of aircraft crashes occur in phases of flight where a "balloon" would have made no difference: controlled flight into terrain, descent below minimums and into the ground, etc.
The "ballistic recovery system" parachute is already in use in the Cirrus. There have been a number of Cirrus crashes where the chute was irrelevant. I think there have been two deployments which were purposeful. I think in one of them, the whole deployment was avoidable. If you have not already familiarized yourself with ballistic recovery systems currently in use or on the drawing boards, it would be a good idea to do so. By the way, the Cirrus chute totals the aircraft when it deploys. It takes out the rear fuselage. And, another thing, my license doesn't include "lighter than air". "Lighter than air" still requires flight controls, propulsion, etc. The Cirrus is only one airplane type. The absence of such systems on all other airplane types might suggest the whole notion is of limited utility. Take a look at the Emergency and Abnormal Procedures sections of a transport category airplane's flight manual. I think you'd find that an aerial flotation system, if there was such a thing and there isn't, would be of little help in most if not all of the situations. I sure wouldn't want it if on fire or if experiencing decompression at altitude. And I wonder what kinds of stresses would be put on the airframe in a high speed deployment. Hey, the half that's still attached to the balloon is floating. Or, what balloon? But, hey, maybe it'll be the next big thing at Cirrus.
P.S. The lifting ability of helium decreases as temperature decreases. You might want to look into that, too.( It was about -60 C at my cruise altitude a few days ago---about -76 F).

2007-07-18 19:24:55 · answer #2 · answered by MALIBU CANYON 4 · 0 0

It depends on the type of helicopter and the type of plane. Most aircraft crashes are light airplanes, like single engine Cessna type aircraft. It is usually due to bad weather and an inexperienced pilot, like the Kennedy character that flew into bad weather and ended up dying. Helicopters have a controlled descent if something fails, but it is different. When an engine fails or the helicopter is no longer "airworthy" it performs something called an auto rotation. If you have ever been in the country and played with those Little seeds that spin when they fall, I can't think of the name of them but they kind of float down and spin. That is what is happening with a helicopter, the blades spin and the air flows upward and it acts like a glider in that fashion. How fast it falls depends on its weight. A light news helicopter Will be pretty controllable and you have a good amount of time to pick your spots to land. A heavy transport helicopter will fall more like a rock and you get little time or range to work with and you better hope your reaction time is good. As for which is safer, they are both safer than driving on the highway, but from the least experienced pilot to the most experienced it is always safer in the day with good weather. By the time you are paying someone they have had plenty of training to know what they are doing. I would fly in either and take a nap and not worry about it.

2016-05-17 05:52:44 · answer #3 · answered by ? 3 · 0 0

Do you have any idea how much helium it would take to inflate a balloon of any size that would even begin to slow just the passenger compartment of a commercial airliner? Several million cubic feet to start with. Look at the Goodyear blimp. I'm not sure of its capacity, but its a lot of helium just to support that little gondola.
Compressing helium to the point where it would even turn liquid let alone solid would require supercooling and it would have to continue at that temperature to remain that way. One little leak or rise in temperature and the whole mess is gone. Just the equipment to maintain that would add several hundred if not thousand pounds to the airframe.
As has been mentioned, ballistic parachutes are a much more plausible solution although the logistics involved in putting chutes on a large airframe would be a challenge with the speed and the amount of weight involved. The ballistic chutes on Cirrus and available for other small aircraft are relatively large as it is.

2007-07-18 15:45:31 · answer #4 · answered by Anonymous · 2 0

In theory it's possible. A GIANT helium balloon. What if the aircraft is on fire. POP. What if it is traveling at 500 MPH. Goodbye balloon. You can visualize the possibilities as aircraft don't just stop in midair. Think of the engineering difficulties and the cost effectiveness of this theory.

2007-07-18 15:32:42 · answer #5 · answered by allen_f_sunderlin 1 · 0 0

Though not a balloon you might be interested in the ballistic recovery system. A small charge fires a parachute from a tube attached to a plane. brings the whole aircraft down for a "soft crash" . so far Ive seen it only on ultra-lights and other single engine general aviation aircraft. scaled up it could theoretically work on larger planes.

2007-07-19 02:17:15 · answer #6 · answered by gort20022 2 · 0 0

This giant balloon would be sliced to pieces by the helicopter's main rotor. Think about it. Where does this balloon deploy from? The bottom of the helicopter? This would case it to flip upside-down, probably spilling the occupants out of the vehicle.

In short, it hasn't been done because it wouldn't work. I am certain you are not the first, nor even the thousandth person to think of this.

2007-07-18 15:39:30 · answer #7 · answered by lithiumdeuteride 7 · 1 0

BIG parachutes are a more realistic answer. Cirrus actually offers them on their aircraft and they will bring the aircraft down reasonably safely if deployed properly.

Additionally, I also suggest that you take your science classes more seriously . . . . . Maybe install big pogo sticks instead of landing gear. Or try usung hydrogen instead of helium. It lifts better. Do a little research and see how THAT turned out last time.

2007-07-18 15:36:37 · answer #8 · answered by Squiggy 7 · 1 0

Sounds good to me. The engineers have been
experimenting with aircraft cock pits or passenger sections that will break away, in case of trouble, and float down with parachutes. Your method would work if it didn't end up too expensive. Good luck. Pops

2007-07-18 15:30:04 · answer #9 · answered by Pops 6 · 1 1

Please take your science classes more seriously? solid anything has mass. And mass falls just like any object. Ballistic parachutes there is an answer..

2007-07-18 15:28:56 · answer #10 · answered by John Paul 7 · 1 2

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