PILOT DECISION MAKING
Lindell Wilson, WVFC CFI LindellWilson@PilotNow.com
Finding Best Glide
How many pilots practice finding best glide attitude and speed? If your answer is, only for a flight review or test, consider reading this article.
The best glide is generally the speed where Lift/Drag ratio is maximized, resulting in the best forward distance for altitude lost. The Airplane Flight Manual (AFM after March 1979) includes several graphs or tables illustrating the best glide speed at different aircraft weights and configurations. The best glide is actually a function of Angle of Attack (AoA), but our light aircraft do not have an AoA indicator, so we use airspeed as a substitute.
What is the best technique to quickly get the airplane to the best glide speed? The key is to establish and hold the right aircraft attitude!
Military pilots learn early in their training (especially in fighters) if the engine fails, PITCH immediately down to a pilot memorized visual (out the window) attitude which approximates the best glide attitude. GA pilots can use this same technique to immediate establish a best glide attitude if necessary. This technique is particularly useful when quick-reaction time is required, for example power loss immediately after takeoff during climb-out. In normal cruise flight, the pilot may choose initially to pitch up to reduce airspeed and momentarily gain altitude as the aircraft trades kinetic energy (airspeed) for increased altitude. The Reno air racers have mastered this technique. The pilot then establishes the memorized best glide attitude.
On your next flight, find and memorize the best glide attitude for your aircraft.