What are Aerobatics?
When it comes to action and noise, the aerobatics are the centerpiece of the shows. Aerobatics are a sort of aeronautical acrobatics—two words that combine to give the sport its name. With specially built airplanes, aerobatics pilots can turn the art of flying on its head—literally. Flying upside down, in corkscrews, fluttering earthward like a leaf, even flying backward—all form a part of a sport that allows pilots to “spread their wings.” For most pilots, flying means flying straight and level, so once we learn how to perform aerobatics, it is liberating for many of us to step into a high-powered, ultra-strong airplane and spend some time turning the craft of flying into art.
Aerobatics rely on four basic maneuvers that pilots combine and string together to create tens of thousands of subtle variations. In fact, the Aresti “dictionary,” created by a Spanish aerobatics genius named Jose Luis Aresti, contains thousands of aerobatic diagrams that pilots use to sketch out their routines. But each of those diagrams is made up of a mixture of the five “letters” of the aerobatics alphabet.
Let’s take a general look at aerobatics in order to make your next air show outing a lot more interesting. Refer to Chapters 7, “How Airplanes Fly, Part 1: The Parts of a Plane,” and 8, “How Airplanes Fly, Part 2: The
Aerodynamics of Flight,” for a description of how throttle, aileron, elevator, and rudder are used together to accomplish these maneuvers.
Turning Flying on its Head
One of the fundamental skills that aerobatic pilots must master is inverted Hying—flying upside down. Inverted flying is a challenge because it’s not just the plane that stands on its head—the pilot does, too. When you’re in the cockpit, your body protests all the blood that gravitates toward your head. (We’ll talk more about the body’s response to aerobatics later in this chapter.) Your instincts about how to use your controls are reversed, too.
Although they might not enjoy it, mo*t pilot* can tolerate the discomfort of flying upside down. But not all plane* can tay the same. In fact, very few airplane* are capable of inverted flight for even a few lecond*. That"* became the system* that pump fuel and oil to the engine often rely on gravity to do their job*, and when gravity « turned upside down—at leait from the airplane’* point of view—fuel and oil *top flowing and that mean* the engine quib running until the plane h once again upright Specially designed aerobatic* plane* are able to pull it off because their engine* arc equipped with fuel pump* and oil system* that keep the engine running and well lubricated regardless of the plane’s attitude.
During inverted flight, every control movement a pilot makes in the cockpit with ailerons, elevators, and rudders has an effect different from what he’d expect in normal, upright flight. (For a review of the effects of the three basic control surfaces, turn back to Chapters 7 and 8.) The elevators provide the clearest example. In upright flight, the pilot pulls the control stick toward him to cause the elevators to make the airplane’s nose move up. In inverted flight, the same control movement actually moves the airplane’s nose toward the earth.
Entering inverted flight involves a highly coordinated series of control movements. First, with a little extra airspeed than usual in order to offset the high drag caused by the slightly steeper pitch attitude once it’s inverted (after all, the airfoil is usually
designed for upright flying, not inverted), the pilot turns the control column to begin a bank in either direction. When the bank angle reaches about 45 degrees, he begins to apply rudder in the opposite direction of the bank and begins to push forward on the control column. As he approaches inverted flight, he gradually reduces the rudder and bank angle, but maintains some forward pressure.
Until a pilot has practiced inverted flight for a while, everything the airplane does seems to be backward. But in order to be able to fly the full repertoire of aerobatics, a pilot has to learn inverted flying.
Putting a Spin on it
Spins are a key tool in the aerobatic pilot’s kit. Think of spins as those maneuvers in which the airplane appears to be twirling downward like a spinning leaf. To execute the traditional spin, a pilot decelerates to a speed that is so slow the wings can no longer provide enough lifting force to keep the plane flying level. That’s the speed where the pilot, using mostly rudder control, intentionally forces the plane to turn in one direction or the other, and the trademark downward spiraling motion begins.
Although acrobatic pilots make the spin look easy, it is sbll a dangerous maneuver. Spins have claimed the lives of some of the best aerobatic pilots in the business, including the legendary Art "The Professor" Scholl, who was killed when he couldn’t pull out of a spin maneuver while filming the Tom Cruise movie Top Gun. We aren’t certain what made it impossible for Scholl to recover from the spin, but factors including disorientab’on, improper balance of cargo, or a malfuncbon with airplane’s controls, and even the design of some airplanes can make spins impossible to stop.
Aerobatic pilots use the spin maneuver as the basis for performing a high – speed stunt called a “snap roll.” The snap roll and the spin look very different and are executed at different speeds. What they have in common is how they are initiated—by a loss of lifting force, which the pilot causes and uses in different ways.
In the spin, the pilot eliminates the lifting force by decelerating to a point where the wings no longer provide lift. In a snap roll, the pilot doesn’t bother to slow down to enter the spiral; he flies at a constant speed and altitude and may even be ascending.
How does he eliminate the lifting force in these circumstances? He uses a combination of full, even abrupt, left or right rudder control while pulling the elevator control sharply backward. This forces the plane to feel the same loss of lifting force that the wings experience in the traditional, slow – speed spin. But because of the snap roll’s higher speed, the result is a startlingly quick rotation that thrills audiences.