1911 R. M. Pierce 231 Tip speed, the oscillatory speed of the tip of a reciprocating wing; the up-and-down velocity of a wing-tip in flapping flight.
1925 22 Oct. 686/2 (caption) The ‘Autogiro’... Note how the high tip speed of the windmill beat our photographer.
1969 (B.S.I.) v. 20 Tip speed, the mean angular velocity of the rotor multiplied by the rotor radius.