Cranfield aircraft handling qualities rating scale: A multidimensional approach to the assessment of aircraft handling qualities

The Cooper-Harper scale is currently the only well-established scale for assessing aircraft handling qualities. However, as a result of having a unidimensional format the Cooper-Harper scale lacks diagnostic power and has also been criticized for exhibiting poor reliability. The Cranfield Aircraft Handling Qualities Rating Scale (CAHQRS) is a new, multidimensional rating scale using concepts from two established scales, the NASA-TLX workload scale and the Cooper-Harper scale. This paper provides an overview of the development of the CAHQRS and the results from a series of validation trials in an engineering flight simulator. An in-flight refuelling task and an approach and landing task using a range of control laws were used in these evaluations. The results showed that the CAHQRS had high positive correlations with the Cooper-Harper scale. However, the CAHQRS also demonstrated greater validity, diagnostic power and higher test/re-test reliability than the previous scale.