A-10 Altimetry System Error Analysis.
Abstract
A study was made to identify and validate field-reported A-10 altimetry system bias. Preliminary evaluation indicated a positive bias (i.e., the aircraft's actual height was lower than the displayed altitude) at the positive extreme of the root sum square of the altimetry system component tolerances. As a result, data taken on actual flights were gathered and statistically analyzed. The results indicate a mean positive bias of 60 feet + or - 99.5 percent confidence level. However, in further analysis interactions were present. Since the interactions could not be made nonsignificant, no direct conclusions concerning the main effects of altitude or aircraft could be made. The altimetry system component analysis demonstrated a positive bias trend, but it was not large enough to explain the flight test results. Ground effects appear to increase the positive bias significantly (i.e., below 100 feet altitude). As a result, it is concluded that there is definitely a positive bias in the system but that a better designed, follow-on flight test is required to pinpoint this bias or main effects that could be further studied.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1981
- Accession Number
- ADA146446
Entities
People
- P. E. Hundley