I told you it was a guess!
You are to be thanked
FED for forcing this retard to do the research to ensure he didn't have the bull by the horns.
Pusher versus tractor tail rotor
The pusher position gives the higher level of net thrust with less power
Neither configuration has excessive net thrust excursion at 20 knots, while the pusher has considerably less thrust excursion than the tractor at 35 knots.
Since the tractor must develop more shaft thrust for a given net thrust because of higher fin forces, the tail rotor in the tractor position will stall sooner than a pusher of the same solidity.
The effects of fin-tail rotor separation distance on tail rotor net and shaft thrust are shown in Figure 2-7. This data is for the pusher configuration with a bottom forward rotation and blockage ratio of 0.207. As the separation distance decreases, both the fin force and shaft thrust increase, so that the net thrust output remains approximately constant. The configuration with the lesser s/r, however, will stall at a "lower net thrust level. Thus, for equal stall tail rotors, the greater the fin-tail rotor separation, the less solidity is required.
From Page 29 of,
http://www.dtic.mil/dtic/tr/fulltext/u2/775391.pdf
