Runway analysis utilizes guidance from both the FAA and ICAO to ensure obstacle and terrain clearance. The FAA has published AC 120-91A, “Airport Obstacle Analysis,” which provides acceptable methods and guidelines for takeoff and climb obstacle analysis. ICAO has a similar publication that closely mirrors the AC 120-91A guidelines but includes slight variations, such as the width of the obstacle corridor considered. These publications and their methods are used in the obstacle analysis evaluation for each takeoff.
To set whether the obstacle corridor is determined based on FAA or ICAO guidance, within ForeFlight Mobile, navigate to More > Aircraft > Your Aircraft > Field Performance. In the Takeoff group, select Obstacle Corridor and select between FAA or ICAO.
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