Would you rather auto-rotate to ground or water, and why?
How specific is your answer to the circumstances?
My choppers are all models, so less damage in the water. The guys who fly real ones may have different priorities.
I am not a chopper pilot but I am not sure why you would think autorotating an emergency landing into water would be preferable under many circumstances. A helicopter and its occupants can survive a well executed autorotated landing with little damage. That isn’t the case for a water landing. The spinning rotors will strike the water probably violently and the helicopter will sink. That complicates evacuation by the occupants and then there is still the matter of being rescued before drowning. There isn’t much good that comes from a helicopter hitting the water.
A helicopter hitting the water will also immediately invert, complicating things.
Anecdotally, from what I’ve seen on “Top 20 Worst Crashes” type TV shows is that water landings are guaranteed to be disastrous, with rotors striking the water, cabins flipping over, cartwheeling and other things that greatly reduce survivability. Furthermore, the helicopter will immediately start to sink and this will complicate salvage and recovery.
A landing on well, land, at least offers the opportunity to bring the skids down onto solid ground that’s not going to cause the helicopter to sink or flip. If all goes well, an autorotation to land is survivable and may even yield a re-usable aircraft once the initial problem has been repaired.
What? I’ve owned several RC Helis, I can’t imagine any way that any of them (ranging in rotor size from 9" to 48") would sustain less damage going in the drink. The rotors suddenly stopping when they hit the water would certainly do damage. Not to mention all the electronics would be ruined.
As far as a a full scale heli? Definitely would prefer a solid ground auto rotation. Done properly, there would be no damage to craft or occupants. Even a perfectly executed auto rotation in to water would certianly destroy the aircraft and would not be pleasant for the passengers - well unless it had pontoons. But, even then, the margin for error is pretty slim.
Given that auto-rotations are routinely practiced right to the ground during training I don’t see why a suitably flat landing area would not be the best option, however I am not a chopper pilot.
As part of my water survival training class, we simulated exiting an inverted helicopter while under water. To help with the realism, we were blindfolded since you probably wouldn’t be able see much, if anything, in such a case. Even after being trained and expecting it, I “drowned” during the first simulation, and just barely survived the second.
So, as a passenger, I’ll take the ground landing.
You are probably better at it than I am. My landings tend to be either pretty good, or disastrous. And I have not actually landed in water. But rotors suddenly stop when they hit the ground too, landing gear, and tail booms and rotors break too. My electric model will probably get its motor and electronics fried, and likely the battery ruined as well. A lot of answers here presume that the auto-rotation, in models or the real thing, results in an ideal descent. But actual emergency situations, and my poor remote piloting skills, don’t always happen that way. Anyway, I’m glad you land your machines better than I do.
My question may seem naive but I’m looking for a more detailed answer. For example, if I were flying over Manhattan I’m pretty sure I’d rather land in the river than land downtown. So considerations would be the availability of potential landing sites without obstruction, and possibility of killing people on the ground.
Say flying from A to B a straight-line path took you over a good-sized lake. Flying around the lake to the South adds 10% to the trip but is over a heavily wooded forest. Flying around the lake to the North adds 25% to the trip but there are some clearings. Which way would you go and why? What if going North would put you at point B with dangerously low fuel? What if it would make you land after dark vs. in daylight?
Dunno, but Robert Mason’s excellent memoir Chickenhawk has a good discussion of autorotations, and how relentlessly they were practiced in Army helicopter-pilot flight school during the Vietnam War era. Their training helis had switches that the instructors could use to cut off the engines whenever they wanted, which more often than not would be at the most inconvenient moments for the pilot trainees. By the time Mason graduated he could autorotate instinctively in virtually any situation.
Not a chopper pilot, but if your engine dies, a normal autorotation to solid ground will end the emergency as soon as you touch down. Then you can get out and laugh about it, call a mechanic and maybe get if fixed and fly it home. With an autorotation into water, the emergency is just starting and if you don’t drown, your chopper is gone. I don’t see anything preferable to landing in water.
One of the first things a pilot does when autorotating is look for a place to land. If the pilot in your scenario can make land, I’m sure that’s where they’ll go. Even if they can’t make it to a large grassy pasture that is perfect for landing a helicopter, they can land on the bank or in a shallow spot near the bank.
Low fuel doesn’t really matter when your engine isn’t running, I think you meant low altitude.
I am. (Non-current because it’s expensive, though.)
Agree. An autorotation landing can be indistinguishable from a normal landing. Should be, if you do it right. Going into the water you’ll likely end up inverted, and the water around these parts is about 42ºF. So now you’re upside down, under water, sinking, and you need to untie yourself, get out, make sure you’re swimming up, inflate your LPU (you’re got one if you’re flying over water, right?), and then be bloody cold until someone comes to fish you out. I’d much rather autorotate to solid ground. Incidentally, a guy autorotated into the Salish Sea off Orcas Island a month or so ago. (He’s accidentally pulled mixture or something and stalled his engine.) His Bell 47 was equipped with pontoons, but it wound up upside-down.
Actually, the pilot should have an emergency landing area in sight and in mind during every phase of the flight; not pick one out when the engine quits. ‘Yeah, yeah. That’s the Party Line, and that’s what they teach you; but who actually does it?’ I do, and so has every heli pilot I’ve flown with.
Elendil’s Heir: I’ve no experience with military training, but I can assure you that we civilians get drilled relentlessly on autorotations. Once you’ve practiced some, instructors like to chop your power at most inconvenient times. Like when you have to have 2,500 feel to get over a mountain ridge on a hot day with two heavy people in a 160 hp Robinson R22. I don’t mind having the throttle chopped. It’s the long climb back to altitude that’s irritating. :mad:
Autorotations are the most fun thing you can do in a helicopter. It’s like having your own personal roller coaster. 
‘Every enterprise contains an element of risk.’
Flying outside of the envelope described by the Height-Velocity Diagram is to be avoided. Still, there are times when you have to fly in the shaded areas. This was practiced a few times in training (e.g., getting into and out of confined areas). My instructor stressed that it’s a calculated risk. It’s highly unlikely that anything will go wrong with the helicopter, so you play the odds. Play the odds long enough, and snake-eyes will roll up. So avoid flying in the ‘dead man’s curve’ and use your knowledge and experience for special situations.
So you’ve got this lake… I would not fly around the south. See what I said in my previous post about always having a landing area in sight and in reach. A heavily-wooded area is a poor place to put down in an emergency. How big is the lake? Given that there probably won’t be a problem, odds are I could fly straight across with no worries. I’d take into account the condition of the helicopter, how soon it’s due for overhaul, whether it’s just come out of maintenance (yes, the first hours after maintenance are a time to be cautious), who’s on the lake and where, and so forth. Extra altitude increases my options, so I’d get high – preferably high enough to glide my noisy brick to safety if I need to. That’s not always possible though. If I had any reservations, I’d take the northern route. Better yet, I’d plan my flight to take advantage of possible landing areas so that I don’t have to overfly the lake.
Regarding fuel: For VFR flight the rules say you have to have enough fuel to make it to your primary destination plus 30 minutes. A preflight weather briefing including winds en-route, and preflight planning so that you don’t run out of fuel save lives.
Re: fuel.
You’re almost certainly better off with the very tiny chance of something mechanical going wrong as you cross the lake than taking the quite large chance that you’ll run out of fuel by taking the long way around.
One point worth mentioning in case anyone thinks otherwise (and I assume the OP may think otherwise) is that if you are coming down too fast (i.e. you’ve screwed up your AR), water will not be significantly ‘softer’ than land.
Also, land badly and get knocked out you will probably regain consciousness sore and groggy, ditch badly and get knocked out you will probably drown.
There are a couple of ways of screwing up an autorotation. Indeed, one of my instructors rolled a helicopter on landing. (I was the next student scheduled.) The greatest error is not getting your collective down in time. Lose rotor RPM and you’re doomed. At that point water or land doesn’t make a difference. On the other hand, you can overspeed your rotor. This will cause mechanical damage, but I don’t know the specifics.
Or you can screw it up at the bottom. In autorotation in an R22 you’re coming down at about 1,200 feet per minute. (This varies depending on weight and conditions.) You slow your rate of descent by flaring at about 40 feet AGL. In my instructor’s crash he flared too late, hit too hard, and ‘dug into soft ground’. R22s and other helicopters are designed to crumple. (That’s why there’s a 250-pound seat weight limit in R22s.) But if you hit hard enough it will hurt. If you don’t land straight, catch a rock, or, like my instructor, ‘dig into soft ground’, you can roll over. Fortunately most helicopters offer decent protection. Of the three helis I’ve flown that other people have crashed, the worst injuries were scrapes and bruises.
Another way to ‘screw up’ is to hit something. Wires can be difficult to see, and other obstacles such as cars, trees, buildings, etc. can be hit.
I’d have to dig out my manual for ditching procedures, but here’s what I remember: If you have enough power (not all power losses are complete ones) and you have a passenger, get as low and slow as possible and have the passenger bail out. Then fly a safe distance away. When your skids touch the water, move your cyclic laterally so that the rotor blades hit the water. This will stop them or break them off so you don’t have whirling bits trying to chop you up when you exit the helicopter. In a total power loss situation your passenger has to ride it in with you. Make a normal autorotation landing and then roll to stop the rotors as above.
Again: It’s very unlikely you’ll have to autorotate. You’ll want to be ready to in case your chip detector light comes on. Sometimes the engine will break, as on this Mooney. If the tail rotor fails, you need to chop power immediately. (The tail rotor is the ‘anti-torque rotor’, so you need to remove the torque.) You can add a small amount of power to extend your glide, but it will twist you a bit. While some crashes are caused by mechanic error (hence, caution after maintenance) or ‘something just broke’ (as in the Mooney), most are caused by pilot error. The pilot forgets to put fuel in the tank. (Nothing more useless than the fuel still at the pump – unless you’re on fire.) Or the pilot will fail to execute proper procedures that had supposedly been indelibly etched into his memory during training, or like my instructor, just makes a mistake. Or he might hit something with the tail rotor and it fails immediately (at 00:23) or later in flight.
So knowing the odds (more or less), I’d have no trouble flying over a body of water. But given the choice, I’d rather autorotate onto dry ground.
From the little I know about helicopters, it seems that the pilot has a terribly important control in each hand, each of which needs continuous attention. How can you scratch your nose when it itches, if you can’t let go?
:smack:
And feet.
The feet control the anti-torque pedals. Once your power is set, you don’t have to keep your feet on the pedals. But it’s a good idea. (Anyway, where else would you put them?)
The right hand controls the cyclic. You don’t want to let go of that one. A video I saw on the R44 shows the pilot taking his hand off of it, and the R44 could fly for a few seconds. Not something I’d try in an R22. Some helis are more stable than others, though helicopters are inherently unstable.
The left hand controls the collective and the throttle. You can let go of that one safely. Pilots generally fly from the right seat. This puts his left hand close to the center console so he can use it to change frequencies, adjust instruments, and use other controls. And to scratch his nose.