What limitation does FAR 135.375 through 135.399 impose on turbo jet landings?

• A. There is no restriction on turbojet landing.
• B. You can depart with any landing distance as long as alternate is dry.
• C. Turbo jets must land within 70% of the runway to depart.
• D. You cannot depart unless landing can be accomplished within 60% of the effective runway at the destination AND the alternate.

Answer: (D)

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.