49.020 Aircraft and space vehicles in general

General requirements for tethered unmanned aircraft systems

Aerospace series - Instruments for measurement of aircraft noise - Performance requirements for systems to measure one-third-actave band sound presure levels in noise certification of transport-category aeroplanes

Electroacoustics - Instruments for measurement of aircraft noise - Performance requirements for systems to measure sound pressure levels in noise certification of aircraft

Fuel cell technologies - Part 4-202: Fuel cell power systems for propulsion and auxiliary power units - Unmanned aircrafts - Performance test methods