Inverted Hover

Cool People Do It Inverted.

There is nothing like carbon fiber blades spinning at 2000 RPMs inches off the deck or the occasional blade scuff to get the adrenaline pumping during a flight. Now you can get your heart pumping a little faster by mastering the basics of inverted flight. Initially the awkward inputs will make the move a little tough, but with enough practice and effort you will be cutting the grass in no time.

SETUP
The proper setup for inverted flight is pretty straightforward. The first thing to make sure you have correct is your pitch setup. The conventional setup for 3D flight is to have at least +10 at the top of the collective and -10 at the bottom. You can also add more pitch for greater pop in 3D flight (see sidebar). When it comes to the throttle curve, if you are not running a governor you want to run an aggressive V-curve on your Idle-up condition(s) for 3D flight. The goal of a V-curve or a governor is to hold the headspeed as consistently as possible, allowing negative pitch to be used without losing headspeed. Make sure you adjust your cyclic travel enough until right before it binds.

Getting there
There are two simple ways to get your helicopter inverted, but first you want to make sure you're comfortable with flipping your helicopter and all orientations of upright flight. You also want to make sure that you're comfortable with the inputs that will be required for inverted flight, so practice on the simulator.

Rolling to inverted
One way to get your helicopter inverted is to simply do a sideways roll. Begin with a tail-in or a nose-in hover (whichever one feels more comfortable to you). Let me explain a tail-in hover. To start off, you want to fly your helicopter three mistakes high, giving you time to recover and save your heli in case you get in trouble. Begin adding a quick cyclic input either to the left or right, whichever one you prefer, but make sure it's fairly quick so that you have enough speed and momentum going into the inverted hover. You can also slow it down and apply more positive pitch as you enter, putting it in a climbing state; just make sure you stop the momentum as easily as possible. Once inverted, apply negative pitch and make sure you're level by compensating with the correct cyclic inputs to keep the helicopter steady. Be easy on the collective because if you apply too much your helicopter will climb more than necessary.

Flipping to inverted
You can also invert by doing either a back flip or a forward flip. When it comes to a back flip, just pull back on the cyclic (remembering, of course, to give yourself the necessary room so that you don't land the heli on its head); once you're inverted, apply negative pitch. If you started from a tail-in-upright hover, you will be nose-in inverted, so apply the nose-in orientation corrections stated below. With a forward flip, just apply forward cyclic, add negative input once again when inverted, and make the needed corrections.

Orientations
All the controls respond the same, but your orientation to the model makes it difficult at first to naturally know which input to give. With tail-in orientation, left and right cyclic input are the same, while forward and back input are backwards. Remember also that your pitch is reversed, so keep your stick in the negative range. You'll move the collective stick down to initiate an inverted climb-out. Tail rotor input can be thought of in one of two ways; you can either think of it as flying the nose backwards, or you can think of flying the tail. When nose-in inverted, forward and backward cyclic input remain the same, while left and right are backwards. Eventually you won't have to play mental games to remember which way to react, but when you are working your way into these uncomfortable orientations, knowing the above tips can help.

Bailing out
This is when knowing how to flip your helicopter comes in handy. For example, if there is a hiccup in any part of the maneuver, just apply the proper inputs to continue the flipping motion that you started. Just make sure to keep the heli away from you at all times. Once you pick a direction, stick with it and follow through; don't change your mind partway through and try to go in a different direction.

Conclusion
Inverted hovering is a little tricky at first, but with enough practice you will be able to impress everyone at the field with your grass-cutting skills. When mastering all orientations of inverted flight, it will help you expand your 3D flying by being able to bail out of maneuvers at any given time. Whether you're a few inches off the deck or high in the sky, inverted hovering is a rewarding maneuver that will never go out of style.