IMHO Helmetfire is right, in that the lift produced by the horizontal tail is very small, in either direction, at common hover/wind speeds. I calculate about 20 pounds of lift from an optimum angle of attack on 20 square feet at 20 mph. Peanuts.
The downwash on the tailcone and horizontal tail is not peanuts, however, and might increase hover performance by 100 to 200 pounds when the downwind hover flow pushes it away from the tail, as opposed to the head wind pushing it onto the tail. As an example, if you recall the Shadow test aircraft we built a few years back, where we grafted a new cockpit onto the nose of the S-76, that cockpit cost us 150 pounds of lost hover performance due to the vertical drag of the extra stuff.
One possible problem in generalizing the benefits of downwind hover from one type helicopter to any other is that the tail rotor wash can upset the main rotor flow if a tailwind pushes it into the main rotor, and this could cause a large increase in power required by the main rotor.
BTW, we call the situation where one hovers with one's ass into the wind as a downwind hover. I will have to tell the old test pilots at Sikorsky how very wrong they have been all these years. Just think, in 7500 hours of flight, the majority in engineering or experimental test, I have not yet got that right. John Bicker,. can you again clarify the situation?
