The Invert Switch

Why not use the invert switch? What's the harm?

After you've flipped the switch and gotten used to flying with the spinning side down, everything is just fine. The problem is the transition when you hit the switch.

The helicopter will 'bobble' a bit because the collective and elevator servos will jump unless you happen to have them precisely centered. Then your brain has to adjust to the change in the way the controls respond. Sure, you still have some adjusting to do without the switch, but at least the transition is smooth and natural (caused by changing orientation), not artificial (caused by flipping a switch).

All this is compounded by the nature of modern '3D' flying, where the heli is alternating between upright and inverted orientations so frequently. Toggling the switch so often would add much more complexity than it's worth, and the inevitable twitching would make it a real challenge to fly smoothly. For an extreme example, watch someone do a metronome and ask yourself, when is the right time to toggle the invert switch?

And if I don't mind the occasional bobble and I don't care about 3D?

If 3D is not your goal, the invert switch is not a terrible idea. It can be fun. I think learning to work the switch is a distraction from learning to fly the helicopter, but that's just me, and who am I to disparage anyone else' fun?

There's one more pitfall: the possibility of having the switch in one position while your brain is expecting the other. Suppose you miss the switch? Suppose you bail out of a maneuver and forget to re-set the switch. Suppose you hit the invert switch while reaching for the idle-up. Each of these is a recipie for disaster.

If the switch is such a bad idea, why do all of the modern radios have one?

I can think of a couple reasons, neither of them persuasive...

First, momentum: there WAS a time when the switch was considered an asset.

I suspect this stems from the fact that there is no easy way to get a proper v-curve out of a non-computer radio. The v-shaped throttle curve is essential to modern 3D setup, but it wasn't an option then. Reversing channels is relatively easy though, so the invert switch was born.

That time has passed. All but the most basic heli radios now support v-curves. The benefits of modern setup are many, and the drawbacks are few. In fact, I'd go so far as to say that there are no drawbacks.

Second, marketing: if someone new to helis is comparing radios feature by feature, the one without the switch is going to seem less desirable than the one with the switch. Implementing an invert switch is a whole lot easier than explaining why you don't need one, so that's what happens.

But isn't inverted flight easier with the switch?

Once you master the technique for toggling the switch and dealing with the control reversals, sure.

But flying inverted is really no more difficult than flying nose-in. It's just another new orientation. If you've learned nose-in, you have what it takes to learn inverted. The fear factor is just higher because you can't set it down safely without flipping upright first, but fundamentally it's no more difficult. Just takes practice to get used to it, like nose-in did, and like tail-in did in the very beginning.

The airplane fliers have never bothered with an invert switch - why should we?