An aircraft indicates 16 000 ft with the correct current QNH set, referenced to a sea-level datum. The outside air temperature is -30°C. Assume ISA temperature decreases by 2°C per 1000 ft, the ISA temperature deviation is constant throughout the layer, and instrument and position errors are negligible. Using the approximate 4%-per-10°C temperature-correction rule, what is the true altitude? - ATPL Question Bank In English