Turbulence

“United 2370 . . . severe turbulence, 4,000 feet.”

We were descending into Burbank when air traffic control broadcast that little attention-getter to the pilots of our 737-300. (On United flights the cockpit-controller transmissions are piped into passengers’ headsets, a bit of performance art that beats the pants off the in-flight Vivaldi.) Sure enough, the plane suddenly bucked emphatically. Out the window I could see, with appalling proximity, winking street lights heaving in and out of view. The buffeting intensified. “Center,” the first officer radioed from the careening flight deck, “do you, ah, have any indication how far down this goes?” Good God, I thought, we’re going to crash in the Northridge Fashion Center. We didn’t, of course, but more than a few ashen souls walked off that plane convinced they’d cheated death.

What our 737 had encountered--as had aircraft arriving that night at airports from Santa Barbara to San Diego--was the vicious low-altitude turbulence caused by the Santa Ana winds. The phenomenon goes largely unremarked but is an annual headache for pilots flying in and out of Southern California during the prime Santa Ana months, October through February.

“The thing I fear the most is the Santa Anas,” says a pilot acquaintance whose single-engine plane was nearly driven into the ground by the winds during a landing in Orange County.

Katabatic, or geography-enhanced, winds like our Santa Anas and the chinooks that prowl the front range of the Rockies create intense turbulence and wind shear that can, in rare instances, flip a small plane and make even the mighty 747 sink like a stone. (A United 737 that crashed in Colorado Springs in 1991 may have been brought down by a swirling katabatic called a rotor, though a malfunctioning rudder is also suspected.) Worse, airplanes often encounter Santa Anas when they are, aerodynamically speaking, at their most vulnerable: at low altitude on landing approaches, with engines throttled back and little room to recover from a stall. “You can be flying along and just stop dead,” my pilot acquaintance notes.

Commercial airline pilots, famous for downplaying turbulence as a routine annoyance, figuratively roll their eyes: No, the wings won’t fall off (airliners are designed to handle stress loads many times greater than what they encounter in choppy air), and no, the sensation that the plane is about to cartwheel into Chatsworth is erroneous. Terrifying, but erroneous. “The Santa Ana winds in general don’t create a particular problem,” says Barry Schiff, a veteran airline captain based in Los Angeles. “Turbulence from the Santa Anas is not the worst you can get. Turbulence within a thunderstorm can be much worse.”

There is, Schiff allows, “a controllability problem--the airplane begins to rock and roll, and you have to try to keep it on an even keel.” Exactly. “It’s kind of like riding a horse--you give it its head, you don’t jerk the airplane, you don’t try to prevent it from responding to the wind. The important thing is you’re not going to get hurt as long as you stay in your seat and keep your seat belt fastened.” Remember that the next time you’re 30 seconds over Van Nuys and the plane is flailing like Joe Cocker at Woodstock.

The day after my landing at Burbank, the Santa Anas were still howling. A colleague arriving on a morning flight at LAX (Santa Anas are strongest before noon and after dark) described the approach over the Pacific as “the worst 15 minutes of my life.” Another, her abdominal muscles sore from being slammed against the seat belt during a roller-coaster approach to Burbank, reported that when the plane finally hit the runway the passengers burst into applause.

“Southwest pilots,” a flight attendant cried over the PA as the reverse-thrusters screamed and a hundred-odd hearts pounded, “rule!”