Subscriber question:
"Engine failure at altitude? Every pilot knows if your engine fails at altitude you should trim for best glide speed. But how many know how far you can travel at a given altitude at best glide. What is a practical method you can use in an emergency for determining the ground distance you can safely travel to make an off airport landing? " - Dan S.
Bob:
“It depends on a lot of factors. Best glide speed in most general aviation aircraft will yield a 500-700 feet per minute sink rate. So depending on your height above the ground, you have a given amount of time before you land.
Obviously your distance traveled will depend on your ground speed. Are you going upwind, downwind or somewhere in between?
With a given height above the ground and a given airspeed, you can now calculate how far you can travel. For example, if you are at 2,500 feet AGL (above ground level), you might have four minutes to reach the ground and cover 4-5 miles.
Having said this, engine failure procedures should not be complicated by trying to include a cross country into them. The best landing area is right below you because it gives you the maximum time to set up for restart and prepare for an eventual landing.
I strongly recommend finding the best landing area close by, rather than trying to find the perfect landing area somewhere in the distance. Trying to stretch the glide has gotten many pilots into serious trouble with stall/spins. Trying to reach a runway has proved costly to several pilots in accidents that I am aware of.”
