RTC – MOD-03 – Pt.05 – Altimeter Settings their Q codes, and their uses

There are multiple reasons why you need to be on the correct Barometric Pressure and because of its importance there have become standardised pressures known as “Altimeter Settings”. But due to their use in early aviation and poor radio communications at the time (often using morse code) they have been abbreviated into what is known as “Q Codes”, many of which are no longer in use, however the ones related to Altimeter Settings are.

The relevant ones we will cover are:

• SAS
• QFE
• QNH
• QNE