After World War II, the various U.S. military branches sent different models of their operational aircraft to the Ames Aeronautical Laboratory located at the Moffett Federal Airfield in Mountain View, California for evaluation of the planes' flight performance and flying qualities.
Most of the flights were conducted by George Cooper, Bob Innis, and Fred Drinkwater and took place at the remote test site at the Crows Landing Naval Auxiliary Landing Field in the central valley area east of Moffett Field.
Cooper developed his rating system over several years as a result of the need to quantify the pilot's judgment of an aircraft's handling in a fashion that could be used in the stability and control design process.
This came about because of his perception of the value that such a system would have, and because of the encouragement of his colleagues in the United States and England who were familiar with his initial attempts.
A series of validation trials in an engineering flight simulator with a range of control laws showed that the CAHQRS was at least as effective as the Cooper–Harper scale.