LF-
20 different answers? Heck, the way I read them, we pretty much all agree:
1. Screen heights have nothing to do with "ground effect".
2. Screen heights are arbitrary values set forth for certification. FAR 121.177 (a),(2) spells out the 50' requirement for recips. For turbojet a/c certified after August 26, 1957 (SR422), FAR 121.189 (d)(1), requires only 35 feet.
3. For any given weight, a lesser flap setting or a faster speed will yield a steeper climb gradient.
4. V2 is NEVER the best angle of climb speed. A lower V2 will get you off the runway in less distance, and you might need that to miss a "close-in" obstacle, but you'll sacrifice gradient capability to do so. (BLCL, are you listening? <grin> ).
5. FAR 121.189 (f) assumes the turbojet a/c will not be banked below 50' for purposes of this discussion.
Roman- The takeoff run is not complete until the turbojet has reached 35'. At that height it is assumed the a/c has accelerated to V2. They are tied together.