Originally Posted by
Otterotor
Helispotter,
The swap of the tail rotor to the left side involved the maximum clearance between the T/R blades and tailboom during maximum flapping. The right-hand side minimised this clearance while the left-hand side maximised this clearance. The aft-over-the-top direction should be described as up-into-main-rotor-downwash (same direction, actual reason for direction of rotation) for additional lift.
Ott
Otterotor: Are you saying the flapping consideration is what motivated a swap 'back' to left-hand side tail rotor on the UH-1Y? If so, does that relate specifically to its 4 blade tail rotor? On earlier 2-blade Hueys the flapping clearance would presumably have been same whether tail rotor was on left or right side?
I had read in one discussion that HU-1 / UH-1 tail rotor changed from right to left and back to right over its evolution, but I haven't so far found any photographic or drawing evidence of an initial right hand side placement. Anyone know more?
As for terminology for tail rotor turning direction, I noticed several ways to describe the same thing (including up into main rotor wash) but created yet another description! Twin screw ship propellers are described as being either "inwards over the top" or "outwards over the top" direction of rotation which is fairly unambiguous.