Originally Posted by
Spooky 2
Intersting discussion. Someone correct me if I'm wrong, but I think the screen height for a wet runway is 35' and 50' feet for a dry runway. This is why you can see a max allowable T.O. weight higher on a wet runway than a dry one when using the Boeing Lap Top Tool or the IPT fuction on the B777 EFB.
Per the current regs, it's 35ft dry and 15ft wet:
§ 25.113 Takeoff distance and takeoff run.
(a) Takeoff distance on a dry runway is the greater of—
(1) The horizontal distance along the takeoff path from the start of the takeoff to the point at which the airplane is 35 feet above the takeoff surface, determined under §25.111 for a dry runway; or
(2) 115 percent of the horizontal distance along the takeoff path, with all engines operating, from the start of the takeoff to the point at which the airplane is 35 feet above the takeoff surface, as determined by a procedure consistent with §25.111.
(b) Takeoff distance on a wet runway is the greater of—
(1) The takeoff distance on a dry runway determined in accordance with paragraph (a) of this section; or
(2) The horizontal distance along the takeoff path from the start of the takeoff to the point at which the airplane is 15 feet above the takeoff surface, achieved in a manner consistent with the achievement of V2before reaching 35 feet above the takeoff surface, determined under §25.111 for a wet runway.