Speed To Fly (IAS) = Best L/D speed + ½ headwind +
5mph for every 100 fpm of sinking air (SGS 2-33).
Glide Angle (GA) = IAS (+TW, -HW) / IAS x L/D@IAS x
SF (50%)
Altitude Lost / Statute Mile = 5280 / GA
Landing Pattern Speed = 1.5 x Stall Speed + ½
headwind on final.