Effects of a 100-Foot Option Altitude Rule and an Annunciator Panel on Failure Detection, Go-around Decisions and Landing Performance

摘要

Twenty rated pilots participated in a simulator study designed to investigate pilot and system responses to control and display system failures occurring during automatic Category III-C instrument approach to landing. The 'option altitude' rule used in the study required that: (1) when a failure occurred above 100 feet, the pilot was required to execute a go-around; (2) when a failure occurred below 100 feet, it was the pilot's option to continue the approach or to go-around. The utility of a failure annunciator panel also was explored. Following failures below 100 feet, pilots continued approach through landing and rollout 382 out of 400 times. Relative to pre-established criteria, only 20% of the manually controlled touchdowns were successful due primarily to excessive sink rates. A majority of the unsuccessful landings occurred during tailwind shear conditions; however, many unsuccessful manually controlled landings also were observed when the tail shear was not present. Autopilot touchdown performance showed similar trends, although autopilot touchdown performance was considerably better. The failure annunciator panel used had no effect upon pilot decisions to land and little effect upon pilot-system performance. Failure detection performance was slightly improved by the annunciator panel. (Author)