The prospects of the helicopter

Warner, Edward P (Massachusetts Inst. of Tech)
naca-tm-107
June 1922


The advantages of helicopters are listed along with a discussion of safety devices, the problems of control, and the need for horizontal flight.

An Adobe Acrobat (PDF) file of the entire report:
http://naca.central.cranfield.ac.uk/reports/1922/naca-tm-107.pdf