A Complete Manual for Conducting International Flight Operations
Conducting hourly altimetry checks is not only recommended in AC 91-70, it is also important from a practical standpoint. If you have ever experienced an altimetry miscompare in a modern aircraft you know that the things will get very busy very quickly. Not only are you not able to operate in RVSM airspace if the altimetry system differs by more than 200 feet, but you may also be faced with an aircraft that is experiencing pressurization issues due to an ADC failure, transponder issues due to the same ADC failure, etc. A point of note, it is possible that primary altimeters may differ as a result of uncoordinated flight. If altimeters are near the 200 foot tolerance evaluate the skid indicator and determine if adjusting the rudder will rectify the altimetry discrepancy.
Revision date: July 29, 2015
JOIN THE CONVERSATION
The material contained on this site is to be used for reference only. You should always follow your primary resources first (aircraft manuals, government regulations, etc.).
Savant Aero is no way affiliated with any aircraft manufacturers.