Tuesday, October 14, 2008

Cross-Controlled


I'm flying an airplane... not sure what type, it doesn't really matter. All I know is that I must land soon, and there's an airport straight ahead... though it's far from my position, just barely visible. Complicating matters is a fierce wind blowing -- stronger than I've ever flown in -- that's pushing me off course, forcing me to crab steeply into the wind to maintain my progress towards the runway.

As my airplane approaches the airport, I know I need to compensate for the wind. I bank the plane's wing into the wind -- it's blowing from the right, which for some reason I know is west in my dream, so I'm on a southerly heading -- and I use opposite (left) rudder to keep the plane's nose centered towards the runway.

This is a sideslip; all fixed wing pilots must know how to perform them before they solo, and most do it by instinct with enough practice landing in crosswinds.

I finally perfected slips during my time in the Gobosh earlier this year. I also became fairly comfortable with forward slips -- which use the same technique as a sideslip but less opposite rudder, to present a larger surface area against the wind. This serves to steepen the descent... a useful tactic when you're high on final, or need to clear a treeline and then land near the end of a short runway.

I'm on the correct glide path; no forward slip needed. I'm not sure whether that's relevant, just as I don't know why I know I'm landing to the south. I'm also keeping an eye on my airspeed; I know I need to stay flying fast enough to avoid an aerodynamic stall.

When flying in a slip, the airplane is cross-controlled. In normal (coordinated) flight, you bank into a turn with aileron input, and use the rudder to swing the plane's nose in the direction you're turning. When you're cross-controlled, though, you're applying opposite inputs -- left aileron, right rudder. You're essentially telling the airplane to fly in two different ways... a very useful skill, as long as you know what you're doing and you're flying at the proper airspeed.

Things are going fine on my imaginary approach... until I'm about a half-mile from the runway. I sense my "plane" starting to slow down. I apply more throttle, but I no longer have an engine; suddenly, I'm in a sailplane.

I fight the urge to raise the nose, which would only serve to lower my airspeed further and accelerate the stall I know is inevitable. Instead, I lower the nose to keep my speed up... but it seems like my plane is now flying in molasses, and the speed continues to plummet faster than I can compensate.

I feel the stall come on before I hear the warning horn. My plane falls out from under me... and since I still have control inputs for the slip in, the plane stalls in an uncoordinated, cross-controlled state. The wing whips over in a wide arc, flipping my plane over and sending me to my doom in a hopeless spiral.

Most everyone who reads this knows about the opportunity I recently passed up. They also know why I turned it down... and why I know that deep down I made the right decision. Or, "the wrong decision for the right reasons," as one of my close friends put it.

I'm not lamenting my decision. I am still trying to come to terms with it. For the past few weeks, I managed to do this by staying busy... keeping my speed up, as it were. Lots of things to do, preparations to make, no time to pause and consider What Might Have Been. This carried me through my recent trip to Orlando.

I've been home for a week now... and I've slowed down. For now, I'm keeping my speed in the white arc, safe from stalling... but I can sense the spiral coming on if I slow down much further.
Funny thing is... I've hardly given any thought to my cancer check-up next week.