This is an old but interesting thread and still it isn't clear to me. My company manual doesn't even refer to this specific situation, probably because we don't operate into any field length weight limited runway. I would like to know if my interpretation of these regulations is correct.
If dispatch calculations don't allow to land within 60% of the LDA in still air conditions, we can still dispatch with an estimated landing weight greater than the landing field weight limit for still wind provided that:
a) with actual wind conditions (50% headwind and 150% tailwind), dispatch calculation permit landing within 60%;
b) 2 alternates meet the dispatch requirement in still air;
c) a pre-landing assessment to ensure compliance with point a is required only up to takeoff or in case of inflight replanning.
I'm really unsure about point C, but so far my interpretation is that after takeoff we can dispense with the 60% of LDA requirement and just work by the Inflight/Enroute performance data. That is, if we get a shortcut, save fuel and current gross weight doesn't meet the 60% dispatch requirement with actual wind, we can land as long as the required landing distance does not exceed the LDA.
And our inflight performance data incorporates a 15% margin for normal configurations.
I might have missed something in the thread and admittedly English isn't my first language. Any inputs?
Last edited by Banana Joe; 2nd Nov 2019 at 13:53.