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NASA Tests Flying Airbag
coondoggie writes "NASA is looking to reduce the deadly impact of helicopter crashes on their pilots and passengers with what the agency calls a high-tech honeycomb airbag known as a deployable energy absorber. So in order to test out its technology NASA dropped a small helicopter from a height of 35 feet to see whether its deployable energy absorber, made up of an expandable honeycomb cushion, could handle the stress. The test crash hit the ground at about 54MPH at a 33 degree angle, what NASA called a relatively severe helicopter crash."
Thought you meant throwing a Senator out the window...
... when you strap my mother-in-law to a turbine engine. The rest of the plane is optional.
One of the main hindrances (the primary hindrance?) to adopting widespread flying cars or other airborne vehicles is safety, and helping to keep people from killing themselves in spectacularly Youtube-worthy ways. The development of an advanced "airbag" like this will really help accelerate the dawn of "highways in the sky", IMO. (Disclaimer: I work for NASA, albeit as an IT geek)
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2. ???
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I liked the system that they had in Demolition Man. When the car that Sylvester Stallone was driving crashed, it filled with foam. Initially, it came out like shaving cream, but by the time the crash had finished, it was like styrofoam. There are two problems I can see with it. The foam will suffocate you if it solidifies around (or even in) your mouth and nose. Also, it may be difficult to extract yourself from the foam.
When our name is on the back of your car, we're behind you all the way!
When I was young I used to wonder whether they couldn't wrap people in a stiff rubber like material that would just bounce off the ground if the plane crashed.
Of course, it would take some time to find you after your superball bounced around the country 23 times.
The thing hit the ground, and what happened? Worst. summary. ever. From nasa: "Engineers say the MD-500 survived relatively intact as a result of the honeycomb cushion. "
A severe crash from 35 feet? How many helecopters do you know travel at a constant 35 feet? Nasa should try at a more reasonable height
This tech acts as a convenient container for your corpse.
Isn't he a riot! Stop in often, tell your friends to come!
...from becoming a helicopter pilot. In fact, just last night my wife said, "sure honey, you can become a pilot just as soon as they invent the deployable energy absorber."
C'MON NASA!!!
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I can't say I've studied helicopter accidents very much, but every one that I've seen video of involved a main rotor or tail rotor failure. The airbag seems like a good idea if the craft can autorotate down to the ground, but if the rotors are compromised you probably aren't going to hit belly first.
Perhaps there is a selection effect? I wouldn't likely see many successful autorotate landings of helicopters since they aren't sensational enough to make it onto the nightly news.
Basic physics: the forces involved in a bouncy collision are *greater* than the forces involved in an identical "smooshy" collision. Why? Because the crash has to not just bring you to a stop, but throw you back away again.
What you want is a smooshy collision that takes place over a long time. Thus, airbags.
TFS didn't mention it, but the helicopter and "passengers" (excluding the skids) survived the crash.
The physics for this does not work out. They can't hit 54 MPH in the space of 35 feet when being dropped with earth's gravity. They'd need to drop it from almost 100 feet to attain that, ignoring wind friction of course. I hesitate to wonder what a networking journal is doing reporting on NASA's activities, especially given the apparent lack of background expertise.
Trecares
On a related note, I think final car safety tests should be performed with the CEOs of the car company inside the car.
Who stated that comment? Oh ya, NASA stated it.
The fact that it hit at a 33* angle suggests that the 54MPH was either groundspeed or total impact velocity, not just the vertical component.
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This site has a video and some more information.
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"The test crash hit the ground at about 54MPH at a 33 degree angle, what NASA called a relatively severe helicopter crash."
I agree. Unless it hits at 300,000 Km/s, let's say a crash is 'relatively severe'.
*double checks your math* Hun... That's funny.
Perhaps you need to go back and study some more physics. In earth gravity of 32ft/s^2 it would take about 2 seconds to hit the ground from 35 feet falling straight down. 2 seconds of earth acceleration has you moving at 64ft/s, which is just over 43mph. Even the lackluster summary states the impact was at 33 degrees, which implies the helicopter was guided in along a slope, rather than being dropped. So using a bit of trig, 35ft/Sine(33) = 64.26ft is the length of slope the helicopter descended, at 33 degrees to the ground, to impact at 54mph, which would then imply that it was actually falling slower than gravitational pull would account for, largely due to the friction of the guide cable. This is likely the same rig used to test reentry mechanisms for many other NASA vehicles, which has the ability to vary impact angle, while maintaining repeatability between each test in a given configuration.
It's close enough to the free-fall velocity in vacuum in km per hour, that I'm suspecting that someone at Networkworld just wasn't paying attention to units. Unfortunately NASA has been hobbled by all kinds of external contractors/suppliers/manufacturers/operators and, apparently, reporters who just aren't quite bright enough to get metric units. Of course any article about anything that NASA supposedly does/did/said that doesn't come with a link to an official souce might as well be considered a fabrication. There's certainly enough of those around on the net.
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Just put weights in it, duh.
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From the article:
"The test conditions imitated what would be a relatively severe helicopter crash. The flight path angle was about 33 degrees and the combined forward and vertical speeds were about 48 feet per second or 33 miles per hour (14.6 meters per second, 53.1 kph)"
Basic physics: the forces involved in a bouncy collision are *greater* than the forces involved in an identical "smooshy" collision. Why? Because the crash has to not just bring you to a stop, but throw you back away again.
What you want is a smooshy collision that takes place over a long time. Thus, airbags.
Reminds me of Hollywood physics, where it's the "ground" that kills, not the "stop". The protagonist is always saved by a safety rope, even if it stops him instantly 1m from the ground after a 1000m fall.
Yeah, that headline is the joke that keeps on giving. Just insert your favorite talking head: Michael Moore, Rush Limbaugh, Hillary Clinton, Sarah Palin, Sean Hannity, Bill O'Reilly, or whoever. . . the list goes on and on - and that's just the U.S. I'm sure people in any country on Earth can find someone to insert into the punchline.
Hopefully they find a way to make that deployable since I doubt anyone is going to put big blocks on the bottom of the helicopter that increase airframe drag.
Must...resist...Rush...Limbaugh...joke...
Table-ized A.I.
Try holding a ball in your hand and then drop it at a 33 degree angle.
Having trouble? Now try throwing it to get the desired angle.
It's going faster now, isn't it?
Obviously they had to do the same with the helicopter.
Yeah, I'm sure climbers and bungee jumpers never thought of that.
A safety rope DOESN'T stop you instantly. A good safety rope is designed to stretch and absorb much of the energy of your fall, and stop your fall over a comparatively long period of time.
Why does clicking on the image lead to an image that is the exact same size? Really annoying and last thing I'd expect on a techie site.
I'm all for using science and research to improve safety, but this seems a little pointless to me. All helicopter crashes can be generally lumped into two categories: those in which control is lost at a relatively high altitude, and those in which control is lost only a short
distance from the ground.
In the former case, no one survives. Once a helicopter pilot loses control of the machine, it has all the aerodynamics of a grand piano and will collide with the ground with much the same effect.
In the latter case, the biggest threat to life and safety isn't the collision with the ground, it's the two giant rotors spinning at an ungodly rate. In a crash, the rotors inevitably strike the ground or a nearby structure and cause all manner of high-velocity objects, material, shrapnel, as well as the rotor blades themselves, to go flying in all directions.
This flying airbag is only going to be of much help in only the best-case crashes where the bird is only a short distance from the ground, perfectly level, and a good distance away from any structures. Go watch some YouTube videos of helicopter crashes. Those kinds of videos completely cured me of wanting to be a helicopter pilot some day. There are lots of ways a pilot can survive even the most severe problem with a normal airplane. In a helicopter, even the slightest mistake can kill you and a lot of other people before you even realize a mistake has been made.
As some know, cars are well equipped with something that is called a crumple zone. Airbags keep your seatbelt from breaking your neck, but the crumple zone is what absorbs most of the force of the crash. See this video for why your crumple zones make a big difference over the air bags.
Something witty.
I really don't know what the heck they mean by "Relatively Intact". In my 3300+ hours of piloting helicopters the only valid criteria was "Could you walk away from it?" That's the standard pilots (and I assume passengers) really care about.
Yeah, I'm sure climbers and bungee jumpers never thought of that.
A safety rope DOESN'T stop you instantly.
But in Hollywood they do. And don't just think ropes, think Spiderman plucking you from the air as you fall (thus not only causing an immediate upward acceleration to break your fall, but a sideways one so you swing away).
Even worse is when the rope instantly stops the person just before they hit the ground, but the rope isn't attached to a harness but around their ankle (so the near-hit is made even more dramatic by it being their *head* that is inches above the ground). With no ankle damage/amputation. And when someone falls off a tall object with a chain wrapped around their neck, they die of suffocation not a broken neck or decapitation (a short fall with a chain could result in suffocation, but I'm talking 30+ feet).
That's Hollywood physics.
A good safety rope is designed to stretch and absorb much of the energy of your fall, and stop your fall over a comparatively long period of time.
More to the point, to be a safety rope in situations where falling is possible, it has to be a dynamic line. Static lines are very dangerous even in short falls.
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Funny, but adding weight *would* increase the energy of the impact as an alternative to going faster. But as others have said, 54MPH is apparently appropriate for simulating a severe crash.
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It's not proper collisions testing unless MythBusters does it. Preferably with big explosions somewhere in the process.
Uhh, physics troll? h = gt^2/2; t = sqrt(2h/g); v = gt = g(sqrt(2h/g)) = sqrt(2gh) = 47 feet per sec = 32 mph. Not sure yet how you get more energy out of an inclined plane, but work it. Anyway, http://www.nasa.gov/topics/aeronautics/features/helo-droptest.html says: "We crash-tested the helicopter by suspending it about 35 feet (10.7 m) into the air using cables. Then, as it swung to the ground, we used pyrotechnics to remove the cables just before the helicopter hit so that it reacted like it would in a real accident," she explained. The test conditions imitated what would be a relatively severe helicopter crash. The flight path angle was about 33 degrees and the combined forward and vertical speeds were about 48 feet per second or 33 miles per hour (14.6 meters per second, 53.1 kph).
Hasn't the FAA watched Looney Toons? Just when the plane Bugs was in was about to crash, he simply stepped out without a scratch!
What you really want is something that absorbs the energy of the motion. You want something that collapses slowly, while arresting as much momentum as possible, and then also have a non-deflating portion as a final cushion. An airbag is not going to do this, at least not an airbag in the common understanding. Now an airbag that slowly deflates as you impact it would meet some of this requirement. I think NASA's honeycomb airbag, probably, is something like this. What I'm describing is used by Hollywood stuntmen to break falls.
Perhaps you need to go back and study some more physics.
(preferrably this time using the metric, international-except-some-countries-dontaskmewhy, system) .
In earth gravity of 32ft/s^2
, or equivalently 23.123 elbows/alittlewhiles^2.
I really appreciated when you translated the 64ft/s to 43mph, it really makes it much more intuitive for the rest of the world.
Please don't be offended
http://www.nasa.gov/topics/aeronautics/features/helo-droptest.html
This could be incredible useful for automobiles. In order to increase efficiency you need to drop weight (as in, stop having SUV-like weight). The problem is that that weight creates a certain amount of crash safety (for the SUV driver to some extent - not so much thought, and not at all for anyone driving a smaller car). Given that, being able to use a light-weight energy absorption system like this could solve that problem and allow cars to have weights below 1000 lbs yet still have excellent crash safety.