I'm guessing 2Slow doesn't have a joystick, or even has his mouse set up.
The game will not allow the elevator or ailerons to be controlled by the keyboard. Too much precision is required. Instead you can map your mouse axis to aileron and elevator. Using the mouse is not quite like a joystick, but AH has it programed to come as close as possible. Extending the mouse from the starting position is like pulling your joystick back, it holds the position unlike many arcade games where you have to keep moving it to keep rolling your plane for example. The trick is to remember you have to be your own spring in a manner of speaking. When you extend it from the starting position you have to return it to the starting position in order to center the control surfaces, unlike a joystick that would center itself.
The trainers page has information and instructions on using your mouse for flight.