Question

What should be the indication on the magnetic compass as you roll into a standard rate turn to the left from a north heading in the Northern Hemisphere?

a) The compass will indicate a turn to the left but at a faster rate than is actually occurring.

b) The compass will initially indicate a turn to the right.

C) The compass will remain on north for a short time, then gradually catch up to the magnetic heading of the aircraft.

Answer 1

In the Northern Hemisphere, when initiating a standard rate turn to the left from a north heading, a magnetic compass will initially remain on north due to inertia before gradually aligning with the aircraft's magnetic heading.

Step-by-step explanation:

When you roll into a standard rate turn to the left from a north heading in the Northern Hemisphere, a magnetic compass will initially show an incorrect turn direction, known as the 'northerly turning error.' Although one might expect the compass to simply start indicating a turn to the left, the compass will initially remain pointed towards north due to inertia.

Continuing the explanation, as you fly due west along the equator, the compass needle, being perpendicular to your direction of motion, points to the right with the needle's north pole pointing north. If the Earth's magnetic north pole coincides with the geographic north pole, as you continue flying due west, the orientation of the compass needle should not change significantly since you are equidistant from the pole at all times while on the equator.

The Earth's magnetic field can be thought of similar to that of a bar magnet where magnetic field lines flow from the magnetic north pole to the magnetic south pole. Due to this field, the compass needle aligns itself in a north-south direction. Significantly, the end of the compass needle that points to the geographical north is actually the south pole of the compass needle; it is attracted to Earth's magnetic south pole, which is near the geographic North Pole.