What should the magnetic compass indicate as you roll into a standard rate turn to the right from a south heading in the Northern Hemisphere?

• A. The compass will indicate a turn to the right, but at a faster rate than actually occurring
• B. The compass will indicate a turn to the left, and at the same rate
• C. The compass will indicate no turn
• D. The compass will indicate a turn to the right, and at the same rate as actual

Answer: (A)

When you roll into a standard-rate turn in the Northern Hemisphere, the magnetic compass doesn’t follow the airplane’s turn perfectly because of the magnetic dip and how the needle responds to changes in heading. From a southerly heading, turning to the right causes the compass to deflect toward the right and, due to the way the dip and the motion interact, the indication tends to show a faster rate of turn than you’re actually making. In other words, the needle suggests you’re turning more quickly to the right than your wings are physically turning the airplane.

So the compass will indicate a turn to the right, and it will overstate the rate of turn compared to the actual rate. It won’t read left, it won’t read no turn, and it’s not a perfect match to the true rate.