What formula do I work out to find true altitude? Appreciate your feedback on this.
Ben
Relationship of true and calibrated (indicated) altitude:
TA= CA + (CA-FE)*(ISADEV)/(273+OAT)
where
TA= True Altitude above sea-level
FE= Field Elevation of station providing the altimeter setting CA= Calibrated altitude= Altitude indicated by altimeter when set to the altimeter setting, corrected for calibration error.
ISADEV= Average deviation from standard temperature from standard in the air column between the station and the aircraft (in C).
OAT= Outside air temperature (at altitude)
Substituting:
FL170 represents a pressure altitude of 17,000 ft
We know that the OAT is -10°C
Indicated altitude is 17,500 ft
ISADEV = (stdISAtemp - (PA * (lapserate)) - differentialfmstdtemp )
TA = 17500 + (17500-0) * (15-17500/1000(2)-(-10)) / (273 - (-10))
TA = 17500 + 17500 * +10 / 283
TA = 17500 + 665.39
TA = 18165
