How would you say the altimeter setting (QNH) to a Center when necessary?

• A. "QNH 29.92" or "Local altimeter 29.92," depending on context.
• B. "QNH 29.92"
• C. "Local altimeter 29.92"
• D. "Altimeter 29.92"

Answer: (A)

When you need to pass the altimeter setting to Center, use clear phraseology that shows what pressure reference you’re using and the actual value. You should say either “QNH” followed by the pressure value, or “Local altimeter” followed by the value, depending on which setting you’re using. For example, you could say “QNH 29.92” or “Local altimeter 29.92.” This keeps the center from guessing which pressure reference you’re applying to your altimeter.

This approach matters because it removes ambiguity about whether you’re reporting mean sea level pressure (QNH) or the current local field setting. Saying the descriptor helps Center understand exactly what you’ve set on your altimeter. Without the descriptor, simply stating a number could be misinterpreted or lead to errors in altitude conversions.