Take-off & landing distance check

The declared distances

TORA is the runway available for the take-off run. TODA adds any clearway, so it covers the distance to 50 ft. ASDA adds any stopway for an abandoned take-off. LDA is the runway available for landing, which may start after a displaced threshold.

The factors

POH figures assume a new aircraft, a test pilot and perfect technique. The UK CAA’s Safety Sense guidance adds about 20% for dry grass, 30% for wet grass, 10% for each 2% of uphill slope and 20% for a tailwind of 10% of lift-off speed, then a safety factor of 1.33 for take-off and 1.43 for landing. Use your POH’s own corrections where it gives them, and never plan on less than you need.