The Arrival of the Tiltrotor

As evidenced by the revolutionary V-22 Osprey, tiltrotors are a remarkable new technology whose time has arrived. However, outside the confines of small clusters of aviation buffs scattered throughout the world, little is known about the evolutionary process that brought us to this point. How were the "convertiplanes" first envisioned and what are the details of their iterative development which required more than a half century of painstaking endeavor to arrive at the position of nearly limitless potential that this promising technology demonstrates today? The purpose of this paper is to elucidate the evolution of this remarkable technology: from the earliest design feasibility studies, performed in England in the 1930s, to the later efforts of Transcendental and Bell Helicopter Textron, Inc., to Bell's novel teaming arrangements of today with significant partners like Boeing and Agusta. This paper will tell the story of the earliest pioneers, like Bell's Robert Lichten who is thought by many to be the "father" of modern tiltrotor technology, and will document many of the "lessons learned" during the considerable time that it took for this exciting new technology to arrive at its current position in the annals of aviation history.