Question

1. An altimeter on a low-speed general aviation aircraft reads 1500 m. The outside air temperature (OAT) is observed to be 7.4°C. The aircraft’s pitot tube measures a pressure of 87050 N/m².
   1. What is the true velocity of the aircraft?

2. What is the equivalent airspeed of the aircraft?

3. Assuming no calibration is required, at sea-level and under ISA conditions, equivalent airspeed (EAS) and indicated airspeed (IAS) are the same. At any other altitude, equivalent airspeed will be less than indicated airspeed. However, below speeds of approximately 200 knots IAS and at altitudes below 10,000', the difference between IAS and EAS is negligible (at higher speeds and altitudes, IAS must be corrected for compressibility error to determine EAS). A useful rough rule of thumb is that true airspeed (TAS) [knots] increases approximately 2% for every 1000 ft. over IAS [knots]. Taking your calculated EAS from part b above as your IAS, how does your answer from parts a and b fit this approximation?

Answer 1