Turning the Circle on Edge
The loop is one of the simplest aerobatic maneuvers to perform and one of the easiest for spectators to recognize. It was also one of the first aerobatic maneuvers to be mastered by early aviators.
German fighter pilot Ernst Udet was among the tint to make his fame by thrilling crowds with the loop maneuver. He added more danger to it than we see today. Instead of beginning and ending the maneuver from a few hundred feet above the ground, Udet would fly along the ground, touch his wheels on the ground, then pull up into his loop. As the loop was nearly complete, he rocketed toward the ground and pulled out just in time to touch his wheels on the ground again to end the stunt.
A pilot begins a loop by accelerating to a fast enough speed to carry the plane over the top of the maneuver, much as a roller coaster car must accelerate before speeding through the looping part of a ride. Then using mostly the elevator control, the pilot pulls the nose higher and higher until the plane is flying on its back. The pilot completes the loop by simply using the elevator to bring the nose “up”—up as seen from the cockpit, which is now upside down—until he recovers from the loop at the same altitude and speed he began at.
A pilot can use the loop maneuver as the basis for doing a number of other stunts. For example, at the top of the loop he can add a snap roll before continuing, a maneuver that pilots call an “avalanche.” (See, we’re already combining the basic aerobatic maneuvers to create complex ones!)
On a Roll
The ailerons, the controls on the wings that help the pilot bank the airplane right and left, can be used at the top of the loop to initiate the aileron roll. If the pilot
moves the aileron control, or stick, quickly to the left, for example, and leaves it there long enough, the plane will rotate toward the left so the left wing is pointed straight at the ground while the right wing is pointed to the sky. That “edgewise” position is sometimes called the knife-edge position, and if the pilot keeps the stick on the left, the plane will actually keep turning until it’s upside down. The aileron roll can be stopped when the wings are level in inverted flight or it can be continued until the plane has rolled 360 degrees and is once again right side up.