Air Doc 18: Sikorsky Helicopter Brochures

Now available: three brochures circa 1968 describing three Sikorsky helicopters:

1) S-65 Compound, a concept design for a large passenger helicopter equipped withwings and turboprops for high speed

2) SH-3D: Describes a number of roles for this amphibious military chopper

3) S-61N: Describes commercial passenger services for the civilian version of the SH-3

Air Doc 18 can be downloaded for $3.50.