Cooper-Harper Scale And Flying Qualities Levels
Effective Date: 15 June 98
Cooper-Harper Scale And Flying Qualities Levels
The rating of aircraft handling qualities is very subjective. It is quite possible to have one pilot consider an aircraft to be "good", and another pilot rate the same aircraft as "unsatisfactory". It is necessary to some standard system for rating the "goodness" of aircraft handling qualities.
The system which is used by the U.S. Air Force is known as the Cooper-Harper rating scale (reference 3). Figure 1 was extracted from reference 3 and shows the Cooper-Harper method for rating handling qualities. In addition to using the Cooper-Harper scale for rating the goodness of aircraft handling qualities, this same scale is used to determine the level of degraded aircraft handling. These levels are used in MIL-8785C to determine requirements for degraded handling qualities. The levels of handling qualities as defined in MIL-8785C are as follows:
Level 1 Flying qualities clearly adequate for the mission flight phase. Aircraft is satisfactory without improvement.
Level 2 Flying qualities adequate to accomplish the mission flight phase, but some increase in pilot workload or degradation in mission effectiveness, or both, exists. Aircraft deficiencies warrant improvement.
Level 3 Flying qualities such that the aircraft can be controlled safely, but pilot workload is excessive or mission effectiveness is inadequate, or both. Category A flight phases can be terminated safely, and category B and C flight phases can be completed. Aircraft deficiencies require improvement.