Is it mathematically possible for a human being to fall through the rotors of a hovering Bell 206 helicopter?

Question

By falling through, I mean uninjured of coarse. The world record for unassisted sky diving speed is recorded at 614 mph (http://en.wikipedia.org/wiki/Freefall#With_air_drag)
The Bell 206 has a Rotor diameter of 33 ft 4 in (10.16 m) but I'm not sure what the minimum rotor speed to hover is.

Answer 1

A rotor blade will pass a given point every 80 milliseconds or so, assuming a two blade rotor turning at 375 rpm. To avoid getting bonked, your person would have to fall six feet in that time, so the speed needed would be on the order of 75 feet per second (around 50 mph). That's not so terribly fast. Considering the adverse consequences of an error in the starting time, I don't think that I shall try it.

Answer 2

Yes it is mathematically possible. I would guess for an average 6 foot tall adult to go through the rotor longitudinally, he/she'd have to be going a lot faster than 614 mph!

It would take some math to figure it all out. It's been a few years since I flew the 206, but I can tell you that the tip speed of a Bell 206 (like all helicopters) at 100% RPM in a hover is around 500-600 mph. The minimum "normal" in-flight RPM is 97%, but in an emergency it will still fly at around 70%. I say %RPM because that is what the flight manual and N2/NR gauge refer to - 100% N2/NR RPM is around 375 RPM but I stand to be corrected on that - give or take 20 RPM.

Answer 3

This human being requested an straightforward question and maximum of you both rewrote it for him or answered what you needed him to ask because you do not comprehend crap about what he DID ask. He requested if there is the kind of aspect as a three-rotor helicopter. He said genuinely no longer something about blades. it is achievable that there have been helicopters with 3 rotors that not in any respect made it previous the attempt level, each and each of the helicopters in use now have both one or 2. For those of you who do not comprehend, it is curiously plenty, unmarried-rotor helicopters are both what's termed "NOTAR", meaning there is not any tail rotor, (air is forced sideways out the tail boost and controls the left-and-excellent action of the tail like the tail rotor usually would), or they have ramjets on the concepts of the rotor blades particularly of an engine using them. Helicopters with one significant rotor pushed by an engine choose both a tail rotor or a NOTAR device to cancel out the torque of the engine that could usually attempt to spin the helicopter contained in the alternative route of the rotor. twin-rotor helicopters with 2 significant rotor platforms have counter-rotating rotors that cancel out one yet another's torque. any more desirable than 2 significant rotor platforms will be an engineering nightmare that could be way too complicated and heavy and not in any respect worth everywhere close to the fee fascinated in coming up and construction it. it is why in small unmarried significant rotor helicopters, designers are going further and extra in the route of the NOTAR device, because it has very few transferring aspects, and is no longer liable to break like a tail rotor is. it would also soak up an dazzling quantity of floor area at the same time as it became parked. there is little need for it.

Answer 4

Taking your question as written, I'm going to say no.

You can't *fall* faster than about 120mph unless you are in air so thin that no helicopter in the world could actually hover there. By the time you got down to the helicopter's maximum altitude (where its rotor would have to be spinning at maximum velocity to hold the hover) the air would have slowed you down too much.

You might be able to do it if you were given one hell of an initial velocity downward while you were close enough to the rotor that you didn't slow down much before entering the plane of the blades, but I think that overly stretches the limits of the concept of "falling" through the rotor.

So, no.

Answer 5

The way I figure it, given that the frequency of rotation is 375 RPM, a blade will hit a given point in the circle 750 times per minute (two blades) or 12.5 times per second. Therefore, the person falling has 0.08 seconds to make it through the rotating blades. A person falling at a rate of 614 mi/hr (274.5 m/sec) will fall 6 ft (1.8 m) in 0.006 sec. Therefore, it is possible to fall through the blades without being hit. It is, however, highly unlikely.

Answer 6

Mathematically is the problem word here. Mathematically, the bumble bee is incorrectly shaped to fly, but it does. Mathematically, it can be shown that a person can outrun a bullet without dodging out of the path of the bullet. By the time bullet arrives at point A, person has moved, point b, etc...but you can't outrun a bullet. So, "mathematically", a person probably could fall through the twirling blades of a helicopter. But, I would not want to be the one to test the math.

Answer 7

It depends on 2 things:
1) the initial velocity of the body when it reaches the blades level,
2) the location where the experiment takes place, specifically - the gravity force there.
In short, it is possible.

Answer 8

Well, there is only one way to find out...

Answer 9

No