Wake turbulence was on every pilot's mind. A few weeks earlier, a business jet crashed while on approach, killing the five people on board. Initial theories of what went wrong focused on the business jet's encounter with the violent, horizontal tornadoes generated by the wings of the large jetliners. The pilot failed to fly above or to the side of a larger jet ahead of him and flipped over without enough time to react. While pedaling through the streets of Dover Shores, I kept glancing back to the south, watching for arrivals of the airliners, hoping to experience a phenomenon that a friend recently described. On the evenings that have arrivals from the south, she would sit outside and listen for the curious sound that whips through the air about a minute after a jet passes.

I did not have to wait long. A Boeing 757, proven to be one of the strongest generators of horizontal tornadoes, also known as wing-tip vortices, or wake turbulence, and the model of aircraft that preceded the ill-fated business jet, was the first to arrive. A man using a vacuum cleaner in his garage made too much noise so I rode farther away while the plane roared overhead. Then, all was silent as the plane dipped behind the knoll. I heard a knobby-tired bicycle riding at twenty miles-per-hour over a thin metal ramp. It lasted four seconds. I looked around, expecting to see someone approaching. But, what I'd heard was the sound of wake turbulence. I built an impressive field of goosebumps.

I waited for the next arrival, with a better idea of what to expect. Several planes lined up a few degrees away from the setting winter sun, but they turned out to be smaller turbo-prop commuters and generated nothing of interest. The next big jet was an MD-80. It passed overhead at about four hundred feet and left behind a moment of silence and then a rush of air, a higher pitched sound like a classroom full of children simultaneously whispering the letter "S."