That’s kinda what I’m confused about. I’ll use an example with generic numbers:
Let’s say you’re leaving KJFK on a 757 at max structural take off at 250,000lbs, you need to add a take off alternate of KBDL. Now, I have a max structural landing weight of say 210,000lbs according to Boeing. But I have runway perf data that says I can land at 250,000lbs and stop the airplane in 60% of the length KBDL’s runway. It’s about a 4,000lb burn from KJFK to KBDL. The 757 cannot dump fuel.
Soooo are we trying to say the airplane is this example needs to have the Take Off weight reduced to the 214,000lbs or that it’s good to go as is with a Take off weight of 250,000lbs? Just trying to have a clear understanding of the original question.
My opinion, in this situation you’re good to go at 250,000lbs because you can stop the plane in under 60% off the runway at the take off alternate (KBDL in this example) and meet the 121.197.