Anyone have an explanation for this and what to do instead?

[ajkavanagh]

Hello

Rank beginner here! I'm new to helis and so far (don't laugh) have a S107G, S800G and now a V911 FP heli.

The curiosity I have is (with the V911):

• Starting with a slow forward flight, holding the cyclic forward.
• Add pitch (to the right) using the tail rotor, and keep this input constant.
• The helicopter starts to turn and then keeps on accelerating until it's going really quite quickly (for my experience so far!)

My questions are:

1. Why does it keep accelerating? I thought it would just turn in and go at the same speed as the forward flight.
2. Is there a way of doing the turn so that it happens at the same speed as the forward flight?

I'm guessing this is something to do with gyroscopic precession (procession?) as in the torque on the body from the rotor causes a tip forward in the body of the helicopter? Or is that completely off the track? Would the reverse happen if I pitch left (turn left with the tail rotor?) - i.e. the heli would slow into the turn as it would pitch the body up? I haven't tried that, as I only seem to be the slightest bit confidence in turning right at the moment!

Thanks
Alex.

[Stevec]

Anyone have an explanation for this and what to do instead?

Hello and welcome to the addiction.

Once you get into non self levelling helicopters ( non coaxial or without a 45 degree flybar) they don't require constant inputs to maintain speed.they are essentially frictionless so if you hold a control input on the helicopter will do more and more until it is either flying at its top speed or crashes.

Remember short stabs of control rather than trying to hold it in.

I am a little confused by the description of using the tail to initiate a turn.

Cyclic pitch is on the main rotor and is both forwards backwards sideways and all other non up and down movement. Collective is the throttle on a fixed pitch machine and the tail is yaw.

So a coordinated turn is usually started by using cyclic and rolling the helicopter you then add tail to push the nose around to the direction you wish to go.

Remember that the helicopter will exhibit different behaviour in left and right turns, is is due to the rotating blades and tends to lose height one way and climb in the opposite direction so you need to be ready on the collective/throttle to compensate.

Sorry if this is a bit basic for you but I thought I'd start at the beginning.

Gyroscopic precession is to do with control inputs happening 90 degrees from the point they originated. Hence the fly bar (what's that these days) affecting what the main blades are doing.

Hope this helps...

Cheers
Steve

[ajkavanagh]

Hi Steve

Thanks very much for your explanation. Sorry it's taken me so long to reply; I've got a growing (slowly!) business and it really is soaking up all my time. Then I blew one of the servos on my (largely obscure) V911 and had to wait 3 weeks for parts from China, which I've just repaired

I've been practicing and can just about do a nice stable nose-in hover and move it in a box, etc. Still enjoying it, but struggling to find the time. On my current progress it's going to be at least May before I will have progressed to a cheap CP heli (130X) and that's both a time and money issue (the new business pains).

Thanks again and I'll keep checking back to the forum.
Cheers
Alex.