Federal Aviation Regulations (FAR) 135 Oral Practice Test

Turbojet operations have a built‑in safety margin for landing performance. FAR 135.375–135.399 require that you cannot depart unless you can land within 60% of the available landing distance on both the destination and the alternate airports. In other words, the estimated landing distance must be no more than 60% of the effective runway length (the usable landing distance) for each airport. This ensures you have adequate margin for braking and contingencies, given the higher performance and stopping characteristics of turbojets. For example, if the destination runway provides 5,000 feet of usable landing distance, you must be able to land in 3,000 feet or less. The same 60% rule applies to the alternate as well. This rule is not about dry versus wet runways and it is not a blanket “no restriction” situation, nor is it about a 70% limit. The requirement is specifically that the landing distance must fit within 60% of the available runway at both the destination and the alternate.