The Use of Analog Track Angle Error Display for Improving Simulated GPS Approach Performance.
Abstract
The effect of adding track angle error (TAE) information to general aviation aircraft cockpit displays used for GPS nonprecision instrument approaches was studied experimentally. Six pilots flew 120 approaches in a Frasca 242 light twin aircraft simulator using crosswind and turbulence. Twenty-five-mile-long approach geometries were used, with and without 45 degree dogleg turns on final approach. Performance and workload using three TAE display formats were compared against results with two control formats presenting cross track error (XTE) only. Pilots found that the TAE displays simplified determination of wind correction angle, and that they consistently chose to use analog rather than numeric TAE data. Statistically significant differences between display formats and between pilots were found. The largest average improvement in initial leg intercept and tracking performance resulted when the conventional 'ten dot' XTE display was supplemented with a sliding pointer display of TAE, moving in the same direction as aircraft bank. A second TAE format, a sliding/rotating pointer integrated display, yielded the greatest improvement (35%) in the width of the short final approach flight technical error envelope, but pilots reported occasional problems interpreting this display. Both of these TAE formats improved final approach intercept and tracking performance after 45 degree turning maneuvers. The addition of TAE information to the receiver display helped pilots create outer Loop Lead, and yielded approach performance improvements comparable to relocating XTE information to an HSI within the pilot's primary scan. Bedford workload scores were not significantly influenced by display format, but were found to depend on approach geometry and phase.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1995
- Accession Number
- ADA304791
Entities
People
- C. M. Oman
- M. S. Huntley Jr.
- S. A. Rasmussen
- S. K. Robinson
Organizations
- John A. Volpe National Transportation Systems Center