14 CFR § 29.81
Landing distance: Category A
July 13, 2020
The horizontal distance required to land and come to a complete stop (or to a speed of approximately 3 knots for water landings) from a point 50 ft above the landing surface must be determined from the approach and landing paths established in accordance with §29.79.
[Doc. No. 24802, 64 FR 45338, Aug. 19, 1999]