Mountain Flying

Ridge Crossing & the 45° Escape

The rule is to cross a ridge at a 45° angle, with a 1,000-foot buffer over the top — 2,000 if the winds are up. The reason is the escape: hit sinking air on the lee side and you turn away toward lower terrain. Cross at 45° and that's a quick turn; cross head-on and it's a full reversal — and every second in the sink costs altitude.

Looking straight down · wind from below

cross + abort sinking air wind over the ridge—

Which side are you crossing from?

Crossing angle to the ridge45°45° is the sweet spot; 90° is head-on — the worst for an abortWind at ridge level20 ktStronger wind = stronger sink on the lee sideBuffer over the ridge1,000 ftThe altitude you carry above the crest before you get there

Abort turn

0°

to reverse

Altitude lost

ft in the abort

Buffer left

ft over crest

Making the crossing

Crossing plan

Plan to be at your crossing altitude at least three miles before the ridge and to hold it three miles past. Cross at 45° so a single turn points you back down toward lower ground, and once you're safely over, turn to get away from the lee turbulence quickly. Which side you approach from is part of the same decision: from the windward side the air is helping you right up to the crest and the abort turns back into it, while arriving out of the lee means you pay for the sink twice — once on the way in and again in the turn.