Heli-ish Times

If you've been paying attention then you know that I now have a GWS Mini Dragonfly electric helicopter, which I have been endeavouring to get a handle on at the end of my driveway.

I guess it has already been said many a time, but these are tricky little suckers. Just the amount of stuff you need to track and keep a handle on is staggering. For example, if you've flown fixed wing RC you have some appreciation of the orientation issues etc, but perhaps not much appreciation for how much input from how many controls is required to keep a heli safe.

For example takeoff on one of these little fixed pitch electrics involes getting your head speed to around 95% of lift required for flight, compensating for main rotor torque with a little right rudder, compensating for the heli's tendency to wander to the left with a little right aileron, all the time trying to figure out whether it is going to go backwards or forwards as well, so compensating with elevator (of course in a heli the aileron and elevator do not refer to actual control surfaces - instead the main rotor blade is deflected in that direction to cause the heli to pitch and yaw - this control is known as the cyclic in a heli). At this stage with all four sticks getting active input from you, the little beastie has still not left the ground - and it only gets worse.

Now - because this is a small electric heli it is strongly affected by it's own downforce (so air it blows into the ground that comes back up into its main and tail rotor meaning that if we just try to gradually climb from this point the thing will just buck and scoot all over the place, no doubt ending in tears. At about 50cms (foot and half or so) from the ground the heli gets out of its own rotor wash and you have one less thing to worry about.

This leads to a manuveur which I have heard a number of persons refer to as "punching it" through to an altitude where you get no ground effect.

So, let's recap. Your main rotor has 95% of the thrust it needs for takeoff. You are already giving input to three controls (right rudder, right cyclic and slightly forward cyclic). You know you need to punch the throttle high enough to lift off, compensate for whatever direction the rotor wash chooses to spit your heli out in, establish a altitude and reduce your throttle when you get there, and compensate for the inevitable pitch and roll. Sound like fun? It certainly is challenging.

Orientation on the heli would be the thing I am having the hardest trouble with I think. For example, when the tail spins due to main rotor torque you do find your self fumbling for whether you need left or right rudder etc.

Although I tried a small takeoff (1 inch - straight into the dreaded ground effect) on the first night, on my second day with the heli I was directed to "RADD's school of rotary flight". This useful set of articles gives some guidelines on how to get a feel for the heli on the ground and even suggests going through 9 batteries before you attempt flight. It's really good stuff.

For example, you put your heli in a 1 foot box on the ground and you have to keep it in that box while doing exercises at close to takeoff rotor speed. It gives you a chance on how to learn to anticipate particular forces (like the heli pulling to the left as it takes off).

So, if you have a heli make sure you read through and maybe do all the stuff that RADD suggests before trying to takeoff.

My Zero has been repaired and is awaiting a re-maiden. The bird is certainly showing her age. Her foam seems quite brittle in comparision to when I first go her. But, I'm pretty confident she is going to make her 200 flights.