Tom Haines

Riding the wake on a Rotax

July 8, 2010 by Thomas B. Haines, Editor in Chief

Flying photography formation flights for our magazines and Web sites teaches our formation pilots a lot about wake turbulence. A recent experience on a “personal watercraft,” (aka, PWC, such as JetSki or SeaDoo), gave me new appreciation for wake turbulence in 2-D. The consequences in the air, however, can be more challenging. Fortunately, most of the time the airplanes we fly in formation with to get the images and videos you enjoy in our media properties are of similar size so catching some wake isn’t usually a huge ordeal.

More than once while flying “subject” for these missions, (in other words, in-trail behind the airplane carrying the photographer), I’ve slipped a little too far toward the six o’clock position and been caught in the photo ship’s wake. In that position, the ailerons momentarily become less effective and you feel like you’re being sucked into a position directly behind the lead airplane with little ability to get out. It’s a passing feeling, often fixed with a kick of the rudder to get out of the wake. I’ve noticed that T-tail or cruciform tail airplanes in the lead are the worst for generating annoying wake.

Of course, shaking it up with larger airplanes near the ground on take off or landing or in trail on approach is a much bigger deal that occasionally causes accidents. The AOPA Air Safety Foundation has numerous electronic aids to help you understand wake turbulence, including an online quiz and online articles.

Riding a PWC this week on Deep Creek Lake in western Maryland, I found the craft being sucked into the wake of boats when riding parallel to the wake, as we do when flying in formation. The result was a rolling motion that seemed to take control of the PWC, making me feel as if I were along for the ride. Turning to cross the wake at 90 degrees led to a more thrilling, jolting ride, but one where I felt more in control.

There’s another interesting parallel between PWCs and aviation. Among the leading brands of PWCs is SeaDoo, which is manufactured by a division of Bombardier, which also makes Challenger business jets; another division of Bombardier makes Rotax engines, which are used in the SeaDoo PWCs. Similar models of Rotax engines are the powerplant of choice for today’s new generation of light sport aircraft, including one that you can win–our 2010 Fun to Fly Sweepstakes Remos GX.

It had been several years since I last rode a PWC. I was impressed by the new Rotax-powered craft and others with how they had switched from noisier, dirtier two-stroke engines to quieter, smoother, and less polluting four-stroke versions. It’s clear a lot of progress has been made in engine technology for LSAs and PWCs. Anyone who hasn’t flown behind a Rotax in the last few years doesn’t understand how important these new engines have become to aviation and the improved reliability over earlier versions of the engines. Our nearly year-long experience with the Rotax in the Remos has been nearly trouble-free. Undoubtedly the high volume of engines produced for the rough-and-tumble PWC world has helped improve the reliability of our aviation engines.

Leave a Reply

*