"Don't use the boost if you're already in the redzone."
The tip found in Learn 2 Fly.
Overview[]
Redzone is the speed limit governing aircraft in all three regular versions of Learn to Fly: Learn to Fly, Learn 2 Fly and Learn to Fly 3, as well as the two mobile versions, Learn to Fly Mobile, and Learn 2 Fly Mobile.
Redzone drag can be reduced by having the Phoenix Feather in Learn 2 Fly, or the Polishing bonus shop upgrade in Learn to Fly 3 (though in Learn to Fly 3 it is referred to as Max Speed)
Trivia[]
Oddly enough, every glider in Learn 2 Fly Mobile has a redzone of 300 km/h.