Expert Flyer Hot Topics – Where the Rubber Meets the Runway
We recently introduced Hot Topics, our new monthly blog on the Expert Flyer site. In keeping with our mission to bring you interesting “hot topics,” Expert Flyer will be featuring a special six-part “Ask the Pilot” series. Our expert, Patrick Smith, is an airline pilot and the author of Salon.com’s popular ASK THE PILOT air travel column. He also hosts the ASK THE PILOT resource site: www.askthepilot.com.
Patrick Smith, Aviator
(Part 1 of 6)
Can you explain exactly what’s happening when the plane flies through an area of turbulence and why it’s not as risky as it feels?
Turbulence is far and away the number one concern of anxious passengers. Intuitively this makes sense. Everybody who steps on a plane is on some level uneasy, and there’s not a more poignant reminder of flying’s innate precariousness than a good walloping at 37,000 feet. It’s easy to picture the airplane as a helpless dinghy in a stormy sea. Boats are occasionally swamped, capsized, or dashed into reefs by swells, so the same must hold true for airplanes. Everything about it seems dangerous.
Except that, in all but the rarest circumstances, it’s not. For all intents and purposes, a plane cannot be flipped upside-down, thrown into a tailspin, or otherwise flung from the sky. Turbulence is an aggravating nuisance for everybody, including the crew, but it’s also, for lack of a better term, normal. From a pilot’s perspective, it is normally seen as a convenience issue, not a safety issue. When a flight changes altitude in search of smoother conditions, this is by and large in the interest of comfort. The pilots aren’t worried about the wings falling off, they’re trying to keep their customers content and relaxed (and everybody’s coffee where it belongs).
In the cockpit we see the altimeter jiggle ever so slightly while the anxious flier perceives a free-fall, overestimating the roughness by orders of magnitude. “We dropped like 3,000 feet in two seconds!” In truth, altitude, bank, and pitch will change only slightly, and inherent in the design of airliners is a trait known to pilots as “positive stability.” Should the aircraft be shoved from its position in space, its nature is to return there, on its own and with no drastic input from the crew.
I remember we hit some pretty heavy turbulence one night over the ocean about halfway to Europe. It was the kind of turbulence people tell their friends about. During the worst of it, to the sound of crashing plates, I kept a close watch on the altimeter. Fewer than 50 feet, either way, is what I saw. Ten or twenty feet, most of the time. Any change in heading (the direction our nose was pointed) was virtually undetectable.
Now, so that I’m not accused of sugar-coating, it is true that powerful turbulence has, on numerous occasions, damaged planes or injured their occupants. With respect to the latter, these are typically people who fell or were thrown about because they weren’t belted in as requested. About sixty people, two-thirds of them flight attendants, are injured by turbulence annually in the United States. That works out to about twenty passengers. Twenty out of the 800 million or so who fly each year in this country.
During moderate to severe turbulence at cruising altitudes, is the plane in autopilot mode or do you take over the controls until things smooth out?
It depends. Some autopilot systems have a special mode for use in such situations. Rather than increasing the number of corrective inputs, it does the opposite, desensitizing the system. Indeed, one of the worst things you can do during severe turbulence is try to fight it. Pilots will slow the jet to its designated “turbulence penetration speed,” assuring high-speed buffet protection (don’t ask) and, worst case, to prevent airframe damage. (This speed is often close to normal cruising speed, however, so you probably wouldn’t notice the deceleration from your seat.)
Stay tuned next week for part 2 of 6, when we find out what makes the pilot sweat when they’re in the cockpit.