arrow2
The reason that I ask is that nobody seems to know. My flight manual says that I must increase the TOD by 6% for each 1% of uphill gradient. If I assume 3%, then I cannot carry a passenger, and have to arrange to meet them at another airfield. The trees seem to be getting taller, although a Yak 52 did lower them by about 5 feet this year.
I have seen some very close shaves this year with heavily loaded aircraft. It is only a matter of time before there is an incident.
So if nobody knows the correct answer, perhaps you can tell be what gradient you use in your performance calculations. Alternatively, if there are any Civil Engineers on the forum, could you tell me how to measure it?
Airclues