ESDU 86006 considers all contributions to pressure errors and the implications of the various tests needed to determine the errors in steady level flight. Typical magnitudes of the various contributions are tabulated for typical installations and, where appropriate, estimation methods are given for particular effects for Mach numbers up to 4 at altitudes up to 120 000 ft (36 600 m). ESDU 85011 deals with corrections for non-steady flight and ESDU 83029 introduces the overall process of correcting for all error sources in flight-test analysis and, in particular, the need for a proper sequence of error correction.