Evaluation of Muscular Forces That Can be Applied to Flight Controls

Abstract

Excessive pilot flight-control forces have been identified as a causal factor in aircraft accidents, incidents, and anomalous events. However, the regulatory design requirements for fixed-wing and rotary-wing air-craft that are contained in the Code of Federal Regulations (CFR) have not been validated or updated in decades, and data for some specific situations were never included in the specifications. Results are presented for a recent study of over 300 participants categorized by gender, pilot/nonpilot status, and age group (10-year brackets from 18 through 69). Controls examined included sticks (left, center, right), yoke, rudder pedals (left, right), and helicopter collective. Results indicated that, on average, more than half of the sample could not achieve the short-term tabled forces used as reference points. However, more than half (60 to 87%) were able to sustain the prescribed long-term forces for 4 minutes or more in some control axes. It is recommended that reference tables both internal to the CFR and referenced by the CFR be modified to accommodate a larger percentage of the current user population.