What does Magnetic bearing (MB) measure?

• A. The rate of turn about the vertical axis.
• B. The direction to or from a radio transmitting station measured relative to magnetic north.
• C. The altitude at which the airplane must fly.
• D. The direction to the destination relative to true north.

Answer: (B)

Magnetic bearing is the angular direction from your aircraft to a radio transmitter, measured with reference to magnetic north. This is the bearing information you get from an automatic direction finder (ADF) when locating a beacon like an NDB—the line from you to the station is given relative to magnetic north. It’s different from how fast you’re turning (rate of turn), your altitude, or the direction to a destination relative to true north. If you need true North references, you’d adjust for magnetic variation to convert the magnetic bearing to a true bearing.