The first part of this paper deals with the tail rotor thrust deficiency experienced by most of today's helicopters, and the various means by which the thrust can be increased, including the use of more blade area, higher tip speeds, and blades having cambered airfoils. The compromises necessary are discussed, including the high pedal loads resulting from any increase in blade chord. Then, in
... [Show full abstract] more detail, a comparison is made of several airfoils suitable for tail rotors, including one with forward camber and one with full camber. The results obtained with two tail rotors using full camber in current development programs are discussed. The second part of the paper considers several alternates to the tail rotor. A hypothetical helicopter is used as a base to compare the performance of a conventional tail rotor with that of a fan-in-the-fin or a tailcone-fan. The theoretical approach used points out some of the inherent limitations of each configuration.