GM1 ACNS.E.RVSM.035 Altimetry System Accuracy

• ED Decision 2013/031/R found in: GM Remote Aerodrome Air Traffic Services (ED 2019/004/R) Issue 2 (Jul 2020)

GM1 ACNS.E.RVSM.035 Altimetry System Accuracy ED Decision 2013/031/R For group aircraft; to evaluate a system against the ASE performance, it is necessary to quantify the mean and three standard deviation values for ASE expressed as ASEmean and ASE3SD. To do this, it is necessary to take into account the different ways in which variations in ASE can arise. The factors that affect ASE are: (a) Unit to unit variability of avionics equipment. (b) Effect of environmental operating conditions on avionics equipment. (c) Airframe to airframe variability of static source error. (d) Effect of flight operating conditions on static source error. Note : Assessment of ASE, whether based on measured or predicted data will need to consider item a to d above. The effect of item d as a variable can be eliminated by evaluating ASE at the most adverse flight condition in an RVSM flight envelope. Appendix A provides two examples of methods to establish and monitor static source errors.