Making Air Travel
SAFER

THE captain pushes the throttles forward, and the first officer acknowledges receiving clearance from air traffic control. Sitting behind the pilots as a cockpit observer, I feel my heart pounding as the jet engines let out a muffled roar. My body is thrust back in my seat as the Boeing 747—a "big iron," in the jargon of pilots—accelerates. Then, with perfect smoothness, we are airborne, and Runway No. 34 of the New Tokyo International Airport falls away behind and below us.

Danger in the Air!

A few moments later, we hear a loud bang, and the aircraft starts to shake and turn violently. An earsplitting sound fills the cockpit. It's an alarm bell! Several red and amber warning lights illuminate the instrument panels as the first officer tries to straighten out the turn.

"Fire number three engine!" shouts the captain as he pushes a button that silences the alarm. "No rotation, no oil pressure, no hydraulics number three," says the first officer. "Throttle back number three. Fuel cutoff number three. Number three pack off." After each command is called out, the appropriate action is taken by one pilot and then verified by the other. As if their movements were choreographed, they work at the situation together. I'm amazed at the way they remain calm and yet act decisively to get the situation under control.

Next, the first officer radios air traffic control requesting emergency landing clearance and asks to have emergency equipment standing by. He then notifies the flight attendants to prepare the cabin for an emergency landing.

As the crew complete their emergency checklists, I try to wipe the perspiration from my brow while holding on tight in my seat! Much to my relief, the plane makes a smooth landing. I also feel a little silly for being so scared. You see, none of the above was real. I wasn't flying over Japan. I was sitting in an advanced flight simulator (similar to the one shown above) at the United Airlines Flight Center, in Denver, Colorado, U.S.A. The flight crew were just training. For me—a veteran of desktop computer flight simulators—this was an exhilarating experience.

Mimics in the Interest of Safety

Similar scenarios are played out by flight crews hundreds of times every day in simulators such as this one. Why? For their training and for the safety of the traveling public—your safety. But why is such training done in simulators rather than in real airplanes? There are many reasons, but before we consider them, let's first take a look at how flight simulation has developed.

During the first and second world wars, schools using rudimentary flight simulators were set up to help with the increased demand for qualified pilots. During the late 1960's, aviation simulation took a great leap forward, as simulators became very realistic. They even began to replicate subtle details, such as the way an airplane handles according to both how much it weighs and how much fuel it has on board. Such factors affect its handling. Then, during the course of a flight, the fuel burns and the aircraft's flight characteristics change. Advances in electronics and computers have made it possible to simulate these and many other conditions.

The goal is to make simulators that mimic real flight as closely as possible. To this end, modern simulators have large, powerful hydraulic bases that give six degrees of motion. The system is powered by large hydraulic pumps that can momentarily subject the flight crew to a range of motion producing a force from +1 to -1 g.*

As pilots adjust the controls, they can feel the results in real time—just as they would in an aircraft. Acceleration, deceleration, roll, pitch, runway touchdown and roughness, and weather conditions are all sensed not only by the pilot's inner ear but also by the rest of his body.

Advancement has been made in the use of computer-created visual systems that depict specific world airports and their surrounding terrain. These true-to-life images are projected on screens that surround the front of the simulator cockpit. The angle of the image is up to 180 degrees in width and 40 degrees in height. Simulators allow pilots to "fly" in all weather conditions—snow, rain, lightning, hail, and fog—and during the day, at dusk, or at night.

Simulated takeoff from San Francisco
and flight over New York City

Visiting a Simulator

The approach to the simulator I visited was a metal bridge crossing a 20-foot [6 m]-wide gap between "land" and a large, white windowless box mounted on a huge movable platform. The device looks like a lunar lander or a giant spider.

Once inside, you feel as if you have just entered the cockpit of an actual aircraft. You see all the dials, indicator lights, gauges, switches, and levers arranged exactly as they are in the aircraft upon which they are modeled. Terry Bansept, my tour guide and a flight simulator technician, noted that many of these panels and instruments are actual aircraft parts.

Terry explained that flight simulators have grown to be full-size, fully functional, exact copies of the cockpit of various models of aircraft. As the use of flight simulation has increased, the aviation community has learned that simulators provide high-quality flight training. Besides teaching pilots to fly, simulated instruction also incorporates training for emergency procedures.

If a simulator meets a certain standard of fidelity, pilots may even log the time spent in it, just as if they had been flying the actual aircraft. Under certain conditions, a pilot's training and testing may take place almost entirely in a simulator.

Why Simulators?

Simulators serve a number of practical purposes. Their use in lieu of actual aircraft saves fuel and oil. It also reduces air-traffic congestion, noise and air pollution, and training and operating costs. To "crash" a simulator costs nothing, and nobody is hurt.

"Simulators may reduce the number of training accidents," Terry said. "They allow for training in handling emergencies, such as engine fire, landing-gear collapse, tire blowout, total loss of thrust, inclement weather, wind shear, icing, and adverse visibility." Also, extensive systems training can be given, and system malfunctions and failures can be handled with no risk to aircraft or human life.

Commenting on this, experienced pilot J. D. Whitlatch observed: "The scenarios we use in the simulators represent 6 million possible combinations of events and conditions. There is no way we could train flight crews for that many experiences in a real airplane."

In the United States, the simulators themselves are carefully checked and certified by the Federal Aviation Administration (FAA), test pilots, and technicians. Before every training day, technicians repair, check, and "fly" their simulators to make sure that these will faithfully replicate the aircraft. When modifications are made to actual aircraft, these changes have to be incorporated into the simulators as well. Every six months, FAA representatives "fly" the simulators to make sure that they are accurate.

Learning From Past Tragedies

By using the information on aircraft flight data recorders and cockpit voice recorders recovered from accident sites, engineers can program simulators to duplicate the exact conditions and malfunctions that occurred in actual and specific aircraft accidents. This information and simulation can then be used as a tool to help investigators determine the cause of individual accidents. In addition, such data can help teach future generations of pilots how to react to unexpected problems. It is also used by aircraft and component manufacturers to determine how to design and construct better aircraft and components in the future.

If an investigation reveals that pilot error caused an accident or a near accident, then training can be initiated so that similar errors can be avoided in the future. Lew Kosich, a seasoned pilot, says: "The scenarios we show are not fictional; they actually happened somewhere." In an effort to improve pilot reactions, training programs, and ultimately public safety, industry experts are continually evaluating and recreating real-life situations and studying pilot reactions to these.

As I now try to "land" the "Boeing 747" at "Charles de Gaulle Airport"—under the watchful eye of my copilot Terry—I expect to hear the sweet chirp of tires touching down on the tarmac. Alas, a bad maneuver freezes the screen of the simulator! I just crashed a "big iron" into the air traffic control tower!

How glad we all can be that the pilots who actually fly passenger planes are real experts—thanks in part to flight simulators. The next time you fly, you can rest assured that you and your fellow passengers are in highly trained hands.—Contributed.

* The symbol g is used to measure acceleration forces that act on people in any kind of vehicle. The earth's gravitational force produces a standard acceleration of 1 g. When a pilot pulls a plane out of a dive, he feels an extra force pushing him down into his seat. If this force is twice that of gravity, it is rated at 2 g's.