Developing Aircraft Altitude Measurement Standards Through Operational Flight Testing and Statistical Risk Analysis

This paper presents a discussion of how aircraft altitude measurement standards were developed by the Federal Aviation Administration for the International Civil Aviation Organization (ICAO) through a combination of altimetry system error measurements by aircraft type and statistical analysis of individual aircraft type performance. The paper presents an analysis that supports the assumption that altimetry system error (ASE) by aircraft type is Gaussian and shows that if ASE is not truly Gaussian but approaches Guassian there is a relatively small effect on the setting of altitude measurement standards.

Altimetry system standards are developed by creating a parametric relationship between altitude keeping (how well assigned flight level is flown) and altitude measurement (how well altitude is measured by the altimetry system).