The string/fishing line method: This method is great for fixed wing aircraft, not so much the helicopters. I'll 'splain why momentarily. Find a tree, a balcony or something with an overhang.
The wife will sometimes work, however, the tree or balcony rarely utters the phrase, "Are we almost done, my arm is getting really tired."
Cut out a lengthy piece of the line, how long will depend on how high up your overhang is. Basically you want your subject to hang just below your shoulders. Tie a loop in the line at both ends and loop it around the nose and the back end of the plane. Now hang the plane from the overhang.
You plane is now "flying." Woo-Hoo!
Take pictures of the plane from all kinds of angles. High shots, low shots, side shots, front shots, rear shots, angle shots, tequila shots. Get every possible angle with the shadows of the vertical stabilizer falling on the plane, or a banking shot where part of the plane is lit part isn't. With your plane hanging there, tilt it to one side or the other so it looks like it's flying on knife edge. Then unhook the plane from how ever you've got it hanging and turn it the other direction. Now all the shadows are falling on it from the other side. Again, take shots from all angles.
A couple of things to watch out for here. First off, make sure no stray shadows from tree branches or something fall across the plane. Nothing like having your plane in the air with a big ol' tree branch falling across it. The other thing, like almost any photo, make sure of reflection. You'd be surprised how shiny some of these things are and the things they'll reflect, especially if it's the black Night Raven or the dark blue Rattler, lighter objects like your own skin can reflect in the paint of these planes.
Have a bit of fun with your plane hanging there. Grab an enemy plane and hold it in your hand. Put the camera near the enemy plane and take pictures of the hanging plane with the enemy plane in frame, then you can have a close up of a dogfight from the enemy plane's point of view.
This technique really only works with the fixed wing planes simply because the balance point on the helos is typically the rotors. One thing I'm going to get into shortly is how to achieve "rotor spin" in your shots. If the helo is hanging by the rotor, the effect is harder to achieve. Yes you, in the back, put your hand down, I know what you're going to ask. Stick around and you just might learn something...
So yes, you can take a picture of a helo using this technique, but, you'll get better results using my next technique.
That covers the string/fishing line method for taking these shots.