Modern Helicopter Theory: A Complete Exposition of Up‐to‐Date Ideas on the Principles of Direct Lift Flight

In recent years little has been published on the mathematical theory of vertical flight, though more intelligent work is being done on the subject by various engineers than, probably, at any previous time. In this and a following article, to be published next month, one of the leading exponents of the helicopter, in a specialised and highly ingenious form, covers the whole field of sustentation, ascent, descent and the thorny problem of stability more completely than has ever hitherto been attempted