AOPA Pilot Magazine - April 2011 - 97

minimum altitude loss during a gliding turn occurs when at an airspeed only 5 percent above stall. I winced at this, too, and certainly would not recommend that anyone fly so perilously close to a stall during such a critical maneuver so close to the ground. If a pilot does choose this option, he should resume the speed for best glide after rolling out of the turn. Another factor is climb speed. Most pilots initially climb after liftoff at either the speed for best angle (VX) or for best rate (VY ). The problem is that neither of these speeds best positions the airplane for the possibility of a turnaround. Climbing at V X places the aircraft in such a nose-high attitude that a pilot must vigorously force the nose down to preserve airspeed following an engine failure. This produces a high initial sink rate, thereby lessening the likelihood of a safe turnaround. Climbing at VY in some airplanes can result in such a shallow climb that insufficient altitude is gained while still close enough to the airport to successfully turn around and land. (This, of course, depends on the airplane; a Pitts Special, for example, can climb steeply enough at either airspeed.) The climb speed that typically places a pilot in the best position for turning around is halfway between VX and VY. So how much height above the ground does a pilot need to turn around safely? This depends, of course, on the airplane and the pilot’s skill. It can be determined with a relatively simple and interesting flight test at a safe altitude. The first step involves establishing the airplane in a full-power climb halfway between VX and VY while on a cardinal heading (north, east, south, or west). When passing through a cardinal altitude (2,000 or 3,000 feet, for example), pull the throttle closed. Delay doing anything, though, for five seconds. This is typically how long it can take for the average pilot to recognize and react to the shock of an actual engine failure. (Rather than allow the nose to drop, hold the nose in climb attitude for these five seconds because this is what many pilots tend to do following engine failure.) After the five seconds elapse, simultaneously roll the airplane into a left or right 45-degree bank and lower the nose so as to establish and maintain no more than the best glide speed (or perhaps slightly less, depending on your comfort level with this). Continue the turn for 270 degrees because reversing course to the runway requires more than a 180-degree turn. A

180 only places the airplane parallel to the runway and displaced to one side. Forty-five degrees of additional turn are needed to return to the runway centerline, and then another 45 degrees to line up with the runway. This means that roughly 270 degrees (180 plus 45 plus 45) are needed to return to the runway. At the end of the 270-degree turn, roll wings level, initiate a simulated flare to zero the sink rate, and note the amount of altitude lost. Increase this altitude loss by 50 percent to account for other factors. If altitude loss during the 270-degree turn is 400 feet, for example, the minimum turnaround height (above the ground) for your airplane would be 600 feet. Perform this maneuver a few times. You likely will discover that you can improve on your first attempt and reduce the altitude loss. Rolling into and holding the 45-degree bank while maintaining best glide speed, however, is initially more challenging than you might imagine. The goal is to become familiar, comfortable, and proficient with the maneuver. There is another important consideration: climb profile. A successful turnaround requires not only reaching the minimum turnaround height, it requires also that you climb to at least two-thirds of that height by the time you pass over the departure end of the runway. This demonstrates that the airplane is capable of reaching the minimum turnaround height while close enough to the airport to have the ability to return. If you are not this high when passing the end of the runway, it means that either the runway is too short or the airplane will be too far from the airport to make a safe return by the time you finally reach the minimum turnaround height. The likelihood of a successful turnaround diminishes when taking off into a strong wind. Landing downwind with a strong tailwind might make it difficult to stop the aircraft within the confines of the airport. At such a time, a pilot might be better off taking advantage of the headwind to land straight ahead with a much-reduced groundspeed. Once a pilot opts to turn around and begins the maneuver, he should turn his head and look toward the runway as soon as possible to visually confirm that he really can glide there safely. Consider also that it might be more convenient and safer to land on a long taxiway or another runway. If it does not appear that you can glide safely to the airport, select the softest off-airport landing site
AOPA PILOT • 97 • APRIL 2011

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AOPA Pilot Magazine - April 2011

Table of Contents for the Digital Edition of AOPA Pilot Magazine - April 2011
