14 CFR § 135.395
Large nontransport category airplanes: Landing limitations: Alternate airports
July 13, 2020
No person may select an airport as an alternate airport for a large nontransport category airplane unless that airplane (at the weight anticipated at the time of arrival), based on the assumptions in §135.393(b), can be brought to a full stop landing within 70 percent of the effective length of the runway.