A、 Outside air temperature is the free air static temperature, obtained either from temperature indications onboard or ground meteorological sources, adjusted for instrument error and compressibility effects.
B、 Outside air temperature is the free air static temperature, acquired either from inflight temperature indications or ground geological sources, modified by instrument error and compression effects.
C、 Outside air temperature is the free air static temperature, derived either from inflight temperature indicators or ground methodological sources, modulating instrument error and compressibility effects.