Instrument Flight Rules (IFR) Practice Exam 2026 – The All-in-One Guide to Master Your IFR Certification!

The magnetic compass exhibits a phenomenon known as magnetic dip or lag during turns, especially when initiating a turn from a south heading. When you roll into a standard rate turn to the right while heading south, the compass will initially show a turn to the left. This happens because the magnetic compass tends to lag behind the actual movement of the aircraft during the turn.

As the aircraft begins the right turn, the compass card, which is aligned with the Earth's magnetic field, is still influenced by the inertia of the aircraft moving south. Thus, it temporarily reflects incorrect heading information. This leads to a false indication that the aircraft is turning left rather than right.

An important aspect to understand is that as the turn continues, the compass will begin to catch up to the aircraft's actual heading, but initially, there is a significant delay in accurate reading. Therefore, it is key for pilots to be aware of this behavior of the magnetic compass, particularly when making turns from cardinal headings. As you gain experience, you will learn to anticipate and compensate for this lag when interpreting compass indications during turns.