Part 25 takeoff/landing performance

New question regarding wet runway landing numbers. There are two ways of getting wet runway numbers for the Lear 45.

First, you have the standard part 135.385 (d) 115% of the dry runway number.
Second, you have the actual landing distances for wet runways chart, from the contaminated runway supplement.
Now, those two come out within 100 or 200 feet of each other for the most part.

BUT.

When you get into the fine print, the wet runway actual data considers MAX TR credit. The 115% rule, being based on the dry runway numbers, does not. If you use actual wet distance numbers, and then adjust for deferred TRs (as we have right now), and the basic part 135.385 (b) 60% rule, you need about a 7000’ runway for a max landing weight, calm wind landing. Using the 115% rule, you only need like 5500’ with the 60% factor.

Do you just go with the conservative number and say hey, we basically need a 7000’ runway right now? Do you go with the less conservative number because hey, it’s legal, and with that 60% rule you’ve still got a ton of wiggle room?

Just a guess, but is there hierarchical control in play here? Your AOM/Opspecs would be more conservative than 135.385, right?

I'm guessing. Do not know, but fascinated by this project of yours.
 
Just a guess, but is there hierarchical control in play here? Your AOM/Opspecs would be more conservative than 135.385, right?

I'm guessing. Do not know, but fascinated by this project of yours.
The only thing our ops specs say about it is that with inop TRs we’re barred from using EOD/80% rule. I should see if they say anything about actual distances vs 115%.
 
I think another corner case at least in the LR45, would be when you are at max gross weight and V1=Vr. I surmise that in that case your accelerate stop is less than your accelerate go, that’s the only reason I can think of that they would recommend that you abort all the way up to Vr. Does it seem like I’m thinking straight there?
It’s not so much a “corner case”, as “this runway is no longer limiting”. We frequently had this on the 777. The sum of the accelerate-go distance and the accelerate-stop distance is less than the runway available. This would also allow for optimised climb (ie higher V speeds), and the available runway distance would still permit a reject.
 
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