Hi Phil- What's this about adjusting Best Glide AoA based on headwind/ tailwind?
If you're trying to maximize glide range in a headwind, you need to go faster than best glide speed. Best glide speed is based on the air, not on the ground - If you have a headwind and you go to best glide speed, you'll be exposed to the headwind for a long time and your glide range will be reduced compared to still air. If you fly the plane somewhat faster than best glide speed, you'll be getting to the ground faster, which means you'll be exposed to that headwind for a shorter amount of time in addition to the faster groundspeed. In many situations, that will make up for the extra drag of going slightly faster.
Likewise, in a tailwind, you'll get your best glide range not at best glide speed, but at minimum sink speed which is less than best glide speed. You'll be going a little slower relative to the air, but you'll spend longer in that tailwind and get blown farther.
As an example - Let's say the airplane's best glide speed is 90 knots and at that speed you're descending 1000 fpm. If you're flying at 10,000 feet into a 20-knot headwind and your best landing site is an airport that's ahead of you and you want to maximize your forward glide into a headwind... Well, if you just fly at best glide it'll take you 10 minutes to get to the ground and your groundspeed will be 70 knots, so you'll travel 11.67 miles. If you increase your airspeed to 100 knots, say vertical speed increases to 1100 fpm, it'll only take you 9 minutes and 5 seconds to get to the ground but your groundspeed will be 80 knots and you'll travel 12.12 miles.
There are limits, of course - If that 10-knot increase results in a 1200 fpm rate of descent instead of 1100 fpm, you'll travel a shorter distance than if you just used best glide. It'd sure be nice if manufacturers included glide data for various speeds in the POH, but they don't - Probably because it's one heckuva lot easier to just remember one number: Vg.
I'm tempted to go out and do some glide testing on the Mooney...
