Helicopter and rope

Comedian Steven Wright had a one-liner along the lines of:
“I got here in a helicopter, but had nowhere to land, so I just tied a rope to it and left it running…” (slowly looks upward)

Is it in fact possible to tie a length of rope to a solid anchor point, lift-off and hover, and slide down the rope and leave the chopper in the air with no-one at the controls?

I am no helicopter pilot, but I would assume you’d need some contraption to hold the throttle in place to keep the machine hovering. You’d also need some way of making fine-tuned adjustments to account for wind gusts etc.

I am not a helicopter pilot either but I do know that they are inherently unstable and require constant control input while hovering. I’m sure that some more advanced helicopters have an autopilot, but I do not know if said autopilots are capable of hovering.

The rope, if tight would also be destabilising, you would need the rope to be loose, in which case there’s no point having the rope at all, and the question becomes “can a helicopter hover on autopilot?”

Maybe not a great idea.

If you do a search on “auto hover helicopter” you will find that there are helicopters that have some sort of auto hover capability. I have no idea as to what the limitations on that capability would be. I rather suspect that the system would be better off left to its own devices and that tying it down would only stuff it up.

I know that in the rather dramatic rescue of a number of yacht crew from vessels participating in the Sydney to Hobart race in 1998 the helicopter pilots mentioned that they were using the auto hover feature to attempt to keep them a certain distance above the massive swells rolling through as they were attempting rescue, but that they had to manually assist because the conditions were too chaotic for the system to cope with. There were gale force winds so in effect the auto hover was flying forward at high speed, although remaining still relative to the person being rescued.

Hmm…Don’t we have some chopper pilots here? I seem to remember** Johnny L.A. ** has flown them before, right?

Is this similar to keeping an airplane on a treadmill? :o

No, but could a helicopter lift off from a fast rising elevator?

Airplanes are inherently stable. You can take your hands and feet off of the controls and they will generally just keep on flying much like they were. Helicopters are inherently unstable and use a different approach. They beat the air into submission to do what they want and the air isn’t happy about it.

Does a helicopter use a dead-man switch like most lawnmowers/boats/tractors? Do pilots disable them like most lawnmower/boat/tractor users?

In the HH-60G, that would be possible, in theory. They do have an ‘auto-hover’ system, but frankly, I wouldn’t bet my life on it.

But one of the things you’d have to worry about is not bumping the collective or cyclic as you’re getting out of the seat. That would be a pain.

IANAHP but I’ve spent a lot of time in them. Several times I’ve had to jump from one as it hovered. The pilot had me coordinate with him very closely as to exactly how we were going to do this because as soon as my weight departed the craft, it’s flight dynamics were going to immediately change and to an appreciable degree.

Even at times when we were just observing an area to land and in a hover, he was often making subtle but important changes to the stick and/or collective due to the wind direction, velocity, etc.

So my guess is that unless you’ve got some strappin’, very capable autopilot device that incorporates GPS, altimeter, anemometer, etc, your answer would likely be a “no.”
(On preview I see RandMcnally mentions one, but with a very important caveat)

Ahem. This was true once but it isn’t any longer for some planes. Modern fighter planes, for example, are inherently unstable in roll and pitch and are stabilzed by an automatic pilot. This is done so as to increase their maneuverabliity.

Even some WWII planes were borderline unstable. The Martin B-26 had neutral roll stability with no dihedral. Fighter planes were close to the line.

In my experience, if I wanted to observe something the pilot much preferred to circle the area rather than hover. Hovering seemed like it took a lot of pilot effort.

In forward flight a helicopter handles similarly to a fixed wing aircraft (note similarly, not the same). In hover it is very different and much harder.

Oh, and I though I had heard about helicopters beating the air into submission, I always thought they were unable to fly, they were just so ugly that the ground rejects them.

If you mean, “would it automatically land itself when the pilot dies?” I don’t have a firm answer for that. Still, “dead-man switch” :eek: is a scary choice of words for a helicopter, IMO.

It also uses less fuel as it’s generating lift though forward motion not just by bashing at the air.

I too ANAHP but I’ve had a couple of ‘fun’ lessons, if you take your hands (and feet) off the controls you will be spinning into the ground in short order. If you’re lucky you’ll land the right way up.

The sensation of using collective is a bit like keeping a broom balanced bristles up in the palm of your hand. It will stay upright but you need to make constant little adjustments to keep it up. Then you’ve got the pedals and collective to keep adjusting as well (for the helicopter that is, not the broom).

Tying a rope an climbing down is not an option. Get a balloon*.

No. I thought that you might be able to let go of the collective but was corrected by a real chopper pilot who pointed out that if the engine fails you have to back off the pitch of the blades** pretty damn sharp or the rotor will drag to a stop leaving you with no lift. So just ignoring the collective is not possible either.

*Waiting for a balloonist to chip in that this isn’t realistic either.

**I don’t remember the terminology.

Interesting. I have been reading more about dead man’s switches and other fail-safe devices. Some interesting reading on these as well as vigilance control devices can be found here:
http://en.wikipedia.org/wiki/Dead_man’s_switch

The watchman’s one legged stool is one example they give of a vigilance control device. The watchman can sit on the stool, but if he falls asleep the stool falls over and he wakes up.

auto rotate

I was thinking about this kind of thing a while back, when I saw a helicopter hovering relatively closeby. Tho it was rather gusty that day, the copter was hanging there stock still, as tho pasted on the sky. My initial reaction was that some mechanical/electronic system had to be keeping him locked in on such a precise location, as it seemed any manual control would reveal some minute variations. But I know nothing about flying copters.