I was on an American Airlines flight from Dallas-Fort Worth to San Francisco last night, somewhere over New Mexico, when the plane rolled dramatically to the left. I didn’t have any instruments, of course, so it was hard to tell how far we rolled, but my impression was that the left wing dipped at least 45 degrees below horizontal. The pilot quickly righted the plane (an old MD80), reduced engine power, and descended a couple thousand feet. We then continued on normally.

It was a slightly alarming moment. I’ve experienced plenty of turbulence in the air, but never such a sudden roll. So it was interesting to hear the pilot come on the PA system a few minutes later to say, “If you’re on the left side of the plane, you’ll see the lights of Santa Fe below, and by the way, that turbulence a while back was from the wake of another airplane. We’ve descended below his path and we should be fine now.”

It’s ironic, I thought at the time, that one of the main aviation hazards at 35,000 feet would be man-made. So it was even more interesting when I saw the Wall Street Journal’s piece today (subscription required) about the Airbus A380, the world’s largest passenger plane, which, not surprisingly, creates an extremely powerful wake. The journal reported that international aviation regulators meeting in Montreal are debating whether to impose special rules requiring greater spacing between the A380 and other planes when it goes into service in 2007.

In the interim, the International Civil Aviation Organization is calling for “minimum separations of 10 nautical miles for all aircraft following a landing A380, compared with the typical five miles required when following today’s largest aircraft,” according to the Journal. That would mean a traffic slowdown at all airports handling A380s – and a big marketing headache for Airbus.

The severity of an aircraft’s wake depends in part on its weight. On my DFW-SFO flight last night, the largest airplane we could have been following was a Boeing 747 – which is 100 tons lighter than the A380. So if my experience was any guide, stricter spacing regulations for the A380 are a good idea. New rules might contribute to Airbus’s existing hassles, including production delays and structural problems in the aircraft’s wings. But would you rather get to your destination a few minutes sooner, or get there in one piece?