Relative Evaluation of Candidate Longitudinal Flying Qualities Criteria Applicable to Flared Landing and Approach

摘要

The MIL-PRIME Standard and Handbook (AD's A123674 and A123726) was designed so that a custom MIL-Standard will be developed for each new procurement or major modification of an existing aircraft. The procedure used to develop a standard is to identify mission requirements, break down mission requirements to mission tasks and select the most appropriate handling qualities criteria from the handbook and insert it into the standard. For the short period response, the requirement guidance section of the handbook lists 6 alternate criteria. This study's purpose was to determine which of the recommended flying qualities criteria provided the best method to predict the short period longitudinal handling qualities levels for the approach and flared landing tasks for transport aircraft. The requirements listed in the handbook were applied to the dynamic configurations and associated pilot ratings provided in NASA CR 178188. Various equivalent system techniques were applied in this study, but none could generate equivalent transfer functions which satisfactorily correlated with pilot ratings. Simpler, less time consuming criteria were the transient peak ratio, rise time, effective delay criteria. This technique provided the same results as the 'best' equivalent system match. The gain attenuation and phase rate criterion from the Dropback and Nichols chart criterion provided the best correlation with pilot evaluations in predicting level 1 and non-level 1 configurations. The time domain criterion, from the alternate criteria proposed in the NASA study, showed good results but seemed highly dependent on aircraft type and task. Short period requirements; Military aircraft landings/approach. (EDC)