Heli aerodynamics question for you experts.

[Chumpy]

I'm relatively new to heli's and am trying to learn why they react the way they do to wind and control input.

When the heli is way up high and I need to bring it back down why does it seem to be extremely unstable when you come down with the collective trying to descend straight down?

What is the best way to descend? I am not comfortable hovering nose in down low yet so I keep the tail towards me close to to ground.

When in forward flight and you want to stop forward motion and hover, what are the control inputs to do this without a lot of bobbing about before settling down? In other word, how do you manage your collective properly during the transition from forward flight to hover?

If you haven't guessed I don't have any experienced help. I fly right outside my shop as there are no clubs or heli pilots that I know of near by.

Any help is greatly appreciated.

All the best,
Chumpy

[Pinecone]

1) If you come down striaght down, you are settling into the rotor wash. You push air down, then descend into it.

2) You raise the nose (aft cyclic) to slow down, lower collective to prevent climbing, then as you slow to a stop, push forward on cyclic to level heli and add collective to hover power.

[Jermo]

I'm new myself but if you are open to suggestion please read the next line, otherwise just skip my post.





STOP! DO NOT FLY YET :shock:

I suggest you immediately start RADD flight school (free) and strictly follow the directions. you'll experience less frustrations and lower cost IMHO.

http://www.dream-models.com/eco/flying-index.html

you will want to learn all the steps up to and including tail-in hover, nose-in hover, 45 degrees, 90 degrees, fig 8s, Ms,..etc..

Just like when we were little, there's the easy way and the hard way. RADD is definately the easy way IMHO. Less stress = more fun :mrgreen: :hug:
jermo

[spork]

When the heli is way up high and I need to bring it back down why does it seem to be extremely unstable when you come down with the collective trying to descend straight down?

What they said is right. You can descend vertically if you have a bit of wind. Otherwise it's easier to descend while in forward flight. In either case, the heli will be easier to control if you keep the headspeed up (idle-up).

[Pinecone]

Yeah, headspeed is important, otherwise you basically have a loss of control authority.

In full scale, this situation with vertical descents is called settling with power, and has caused crashes. The thing is you can actually fly into yoru own downwash, and run out of pitch and power and still be going down.

[Chumpy]

Makes sense. Thanks! And thanks Pinecone for the transition flight lesson. Something to work on.

All the best,
Chumpy