Final answer:
True north refers to the Earth's geographic North Pole, and magnetic north aligns with the Earth's magnetic field which compass needles point towards. In a scenario where the magnetic north pole is at the geographic North Pole, the orientation of a compass needle will not change when flying due west along the equator. Magnetic north is the magnetic south pole of a hypothetical Earth bar magnet.
Step-by-step explanation:
The concepts of true north and magnetic north are fundamental in navigation. True north refers to the direction of the Earth's geographic North Pole, whereas magnetic north pertains to the direction that a magnetic compass needle points, which aligns with Earth's magnetic field. The Earth's magnetic north is not a fixed point and can differ from the geographic North Pole.
In the simplified scenario where Earth's magnetic north pole coincides with its geographic north pole, an airplane flying due west along the equator will observe the compass needle pointing to the right, aligning north-south. As the plane continues its due west course, the orientation of the compass needle will not change, as it will continue to align with Earth's magnetic field.
It is worth noting that magnetic field lines always point from the magnetic north to magnetic south, and the Earth's magnetic field is such that the magnetic north pole is actually the magnetic south pole of an equivalent bar magnet, demonstrating the attractor role for the compass's north.