Unknown-Attitude Recoveries Using Conventional and Terrain-Depicting Attitude Indicators: Difference Testing, Equivalence Testing, and Equivalent Level of Safety

Abstract

The objectives of this study were to assess the effects of differing formats of forward-looking primary flight display (PFD; electronic attitude-direction indicator, full-color terrain, uniformly brown terrain) on general aviation (GA) pilot recoveries from unknown attitudes and to determine if recovery assistance embodied in the display could be useful. Total recovery times and control reversals were examined as indexes of performance for 40 GA pilots, and the recovery times were subjected to a comparative analysis using both a parametric difference analysis and an equivalence testing technique. Results suggest that for the specific conditions investigated, terrain-depicting PFDs supported performance that was equivalent to that observed with the standard attitude indicator. Equivalence testing is recommended for cases where it is desirable to determine if one device or system provides for performance that is equivalent to another.It is frequently necessary to determine whether some system or product can be said to be equivalent in its performance to something else. There are several application areas in which it would be valuable to be able to present quantitative analyses of the relative performance of two things where we are not so much interested in determining that the distributions of performance scores are different (traditional

Attitude Indicator Design in Primary Flight Display: Revisiting an Old Issue With Current Technology

“…However, other new developments are already available in some modern cockpits, which might create entirely new circumstances for the evaluation of proper AI formats, such as synthetic vision and head-up displays. With these displays, the issue of MH versus MA could be different (e.g., Beringer & Ball, 2009) and more research will be needed to see whether this issue eventually will become moot.…”

Attitude Indicator Format

“…A further limitation is that we only tested AIs implemented in head-down PFDs. The situation might be different for synthetic-vision or head-up displays (Beringer & Ball, 2009; Ercoline, DeVilbiss, & Evans, 2004; Pongratz, Vaic, Reinecke, Ercoline, & Cohen, 1999), which remain a matter of future research.…”

The Use of Enhanced Flight Vision Systems (EFVS) for Low-visibility Takeoffs in Part 121 Operations

“…Flight-performance data (deviation from runway centerline while in ground contact and stopping distance on rejected takeoffs) were analyzed using ANOVA techniques with IBM SPSS Statistics for Windows version 24 (IBM Corp., Armonk, N.Y., USA). Additionally, equivalence testing was performed with the TOST equivalence testing R package (Lakens, 2017;Beringer & Ball, 2009) to evaluate the degree to which performance on specific trials appeared equivalent to baseline performance (an assessment of equivalent level of safety). Subjective data (workload self-assessment) were analyzed using nonparametric statistics for ordinal data.…”