Like full size helicopters, are radio control helicopters subject to the condition "settling with power"?

Thanks,
Glenn

I have never seen it. Mostly because our small helis are always moving. Settling usually occurs in a high hover situation out of ground effect.


Jeff

I didn't know what that meant. So I looked it up. In case anyones interested here's an explination:
http://www.helicoptersonly.com/Maneu...ith_power.html

Oh yeah, you can settle with power! Just try landing downwind into a hover from forward flight with a fairly steep profile. Be ready to push cyclic and fly out of it or buy rotorblades, tailtube, etc. We got the advantage these days of power up the kazoo to fly ourselves out of trouble for the most part. In the early years of underpowered, fixed pitch and slow reacting cyclics, it was a smart guy who carefully planned his approach to hover. Now we just goose it and go! I know this will draw gunfire from some but what you run across in modeling is all present in full scale aviation. Were in the same air. The scale effects do change our perception of what is happening though. I fly full scale aircraft in addition to model aircraft and model aircraft mostly just resemble their full size counterparts due to considrations made to keep them easy to fly. Not always but much of the time. No considerations to range, speed and load carrying capability not to mention CG range are of much concern to modelers. We gas and go. Modelers for the most part got it great on the power to weight ratios, especially in helis. To relate to a full scale heli like a Hiller 12C, You can barely pull back into a ground effect hover at 5000 ft density altitude with two aboard and half fuel. Which for all practical purposes elliminates flying it like a heli. This means hover taxi and departure down the runway..ala airplane mode. Imagine putting up with such performance in a model! I know I'm digressing but thought some who never flew anything other then model helis might be interested in the comparisons. I know decending downwind to landing in a piston heli is bad form for sure. It might turn into downwind splat instead of a nice hover. Also, to clarify, I have only a fixed wing rating and not heli. I just have been fortunate to get considerable time in such machines.

Other heli phenomenum that I've never heard associated with RC helis are:

LTE: Loss of tail rotor effectiveness

Ground Resonance (very bad)

Dynamic rollover

Retreating blade stall (Anybody experience this in a RC Heli?)

I know I've "accomplished" something similair in G2 But I was learning how to take off & hover at the time. So I don't think it was actually:

Helicopter Dynamic Rollover


An increasing percentage of helicopter accidents are being attributed to dynamic rollover, a phenomenon that will, without immediate corrective action, result in destruction of the helicopter and possible serious injury. We hope this artical will inform helicopter flightcrews of the cause of helicopter dynamic rollover and measures to take to prevent such occurrences.

Helicopter pilots in general are required to be skillful in operations on both improved or unimproved surfaces. During normal or slope takeoffs and landings with same degree of bank angle or side drift with one skid/wheel on the ground, the bank angle or side drift can place the helicopter in a situation where it is pivoting (rolling) about a skid/wheel which is still in contact with the ground. When this happens, lateral cyclic control response becomes more sluggish and less effective than for a free hovering helicopter. Consequently, if a roll rate is permitted to develop, a critical bank angle (the angle between the helicopter and the horizon) may be reached where roll cannot be corrected, even with full lateral cyclic, and the helicopter will roll over onto its side. As the roll rate increases, the angle at which recovery is still possible is significantly reduced. The critical rollover angle is also reduced.

The critical rollover angle is further reduced under the following conditions:
a. Right side skid down condition
b. Crosswinds
c. Lateral center of gravity offset
d. Main rotor thrust almost equal to helicopter weight and
e. Left yaw inputs.

When certain elements of helicopter operations are at or near their most critical condition, such as high gross weight, right lateral center of gravity, crosswind from the left, hovering with only the right skid/wheel in contact with the surface and with thrust (lift) approximately equal to the weight, very little right roll rate is correctable for any given bank angle.

Info from:http://www.helicoptersonly.com/

I'm not a big heli buff, (hope to be though eventually) but I notice the same sort of thing while playing Battlefield 1942, using Desert Combat version, flying the helis.
It's mostly noted when I'm coming in to do a landing, one wheel touches the ground while i have maybe a hair too much side moving going on, the wheel touches, and then flips the helicopter over on it's side on the ground.
Is this the same thing or is that just a bad landing? Usually I can make landings very good if I come in going straight forward. But taking off at an angle most of the time has it flip over.
We're just talking a game here too, and a game that isn't designed for helis or flight simulation with much in mind to begin with. But I guess the physics still make sense, having the disc not in perpendicular to the force of gravity and having a wheel/skid in contact giving a point for leverage and grip to throw the helicopter around.

i think you guys are giving too much (or too little) credit to r/c helis in applying them to real helicopters. the power to weight ratio is so disparate that our toys aren't subject to the same forces as the big ones. you can lift off an r/c heli at an angle without rolling over and we're never subject to "maximum gross weight" or "right lateral cg." if you want to fly r/c, i'd recommend learning from scratch and not relying on the real ones to mirror our models in performance.

Its obvious what I posted was related to a full scale heli I was just basically posting the "definition"(s), of the terms, because I haven't heard of them & figured maybe someone else hasn't. I never said the same phenoms could happen with a rc heli, although scale to scale I believe there has to be some similarity. But I'm new to this stuff still, and just started to read today in depth, about the physics of how a heli fly's. So I guess my opinion doesn't count for too much Its very obvious that rc helis can do much more than a full scale heli. So these phenomenons may occur without fully realizing it because the rc heli can handle "the pressure" better. Just a rookies 2 cents which probably aint worth much

The reason we don't see retreating blade stall on models is our relatively slow foward speeds compared to full scale. Not much chance of stalling a blade at our 70-80 mph speeds. Anyone remember the Cheyenne heli that the army never built? They managed to relieve that trouble by slowing the main rotor to a comparative crawl and let the stubby wings take over some of the load and used a pusher propeller configuration if memory serves me correct? Kind of resembled a gyrocopter with the rotor disk almost flat going 268 mph. Pretty impressive but never got produced. Ground resonance on the other hand is one of those things that dosen't seem to translate to smaller scale by virtue I would guess of our incredibely rigid airframes and rotor blades. In full scale vibration would kill the airframes if they were half as rigid as our models. Same thing with the flapping blades vs solid feathering spindles. A full scale Bell looks kind of loosy goosey when you compare it to our rigid rotor setups in models. I understand not all are alike, but most of the popular models are this way.

In an attempt to make the differences between Full Scale and R/C more apparent.... I have never heard of a full scale hovering inverted.

Even so, RC Helis cannot escape the Laws of Physics (although they appear to), and settling with power aka vortex ringstate can be entered in certain conditions as described previously. (downwind, low rpm, steep approach etc)

Well... having never flown a full size heli, I can't speak on that subject. But, I have for a fact entered my own downwash with my RC heli's.

I notice it is especially bad when hovering around with no wind blowing at all.

It is a sick sound when your heli enters it's downwash. If you've heard it, you'll know what I mean.