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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.
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. "
I think the bigger problem is what people will run into. I personally do not look forward to some soccer mom flying around in an SUV-like thing near my house.
Here's my question, which I also found myself thinking after watching Iron Man. Sure enough, the foam or the super exoskeleton or whatever can protect the outside of your body and the bones from harm when undergoing a sudden deceleration, such as crashing or whatnot, but what about all of the soft things sloshing around inside your body, like your brain, your viscera, etc? Surely they are going to, well, *slosh* around violently upon a sudden stop like that. I think boxers have proved that point very well over the years.
Yes, they are fiction and I treat them accordingly, but such egregious fact-ignoring is a bit scary sometimes.
...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!!!
Helicopters can auto-rotate so crashing into the ground at 50-60mph like they say is a pretty severe crash.
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.
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how many helicopters are generating zero lift when they hit the ground? What's important is not the height of helicopter crashes, but the speed. I can certainly imagine worse accidents than 53mph at 33 degrees, but I'm willing to take NASA's word for it that this is "relatively severe."
On a related note, I think final car safety tests should be performed with the CEOs of the car company inside the car.
every one that I've seen video of involved a main rotor or tail rotor failure
The more spectacular helicopter crashes happen this way, but loss of power events are more common. The most severe of these occur at low altitudes as there isn't enough time to successfully autorotate. So this type of device should improve survivability in the most common crash/hard landing scenarios.
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[sigh] Yes, but any helicopter that crashes from ABOVE 35 feet must also travel THROUGH 35 feet, thus a 35-foot test elevation should substitute for most helicopter crashes. One could certainly argue that a 5-foot test would effectively sample more scenarios than a 35-foot test, so perhaps they should test based upon that height instead. When will science learn that if you just use the right logic no one has to die.
This site has a video and some more information.
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http://en.wikipedia.org/wiki/Autorotation_(helicopter) Au contraire, mon bon sieur.
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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.
Just put weights in it, duh.
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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.
Mercedes and BMW are both heavily investing in stuff that will make the autonomous vehicle a reality in a few years. Some things are already making it to the production line as we speak, like automatic brake control (http://en.wikipedia.org/wiki/Sensotronic_Brake_Control) and automated parking systems (http://gizmodo.com/196551/lexus-self-parking-car-video-and-review) just to name a couple.
Personally, I'd like to see something that locks (or jettisons) the rotor
I'm pretty sure that the poor schmuck watching on the ground would prefer your rotor to lock rather than jettison. Imagine a giant ninja start flying at your head.
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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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Big sky theory. This of course stops as soon as you fill the air with flying cars.
If you're flying too slow and low to the ground, there is less time to recover and perform an autorotation. In a heli's flight envelope, this is often referred to as the dead man's curve.