Final answer:
Using the right-hand rule and understanding the orientation of the magnetic field helps address the magnetic variation experienced when flying due west along the equator, with minimal deviations expected.
Step-by-step explanation:
When dealing with easterly variation in magnetic direction while flying due west along the equator, assuming that the Earth's magnetic and geographic poles coincide, the orientation of a compass needle will experience changes.
As the airplane continues to fly due west from the prime meridian, the magnetic field B at equatorial regions will largely align with the Earth's rotation, with magnetic compasses aligning themselves parallel to these lines of force. However, the variation in the Earth's magnetic field can cause the compass needle to deviate slightly, as local anomalies or changes in magnetic declination occur.
The two steps to address this issue include:
- Orienting the right hand so that the fingers curl in the plane defined by the velocity and magnetic field vectors, and
- Using the right-hand rule to determine the direction of the compass needle's alignment as influenced by the magnetic field.
It is important to note that the compass will most likely remain pointing towards magnetic north, which in our simplified case is also geographic north, so the magnetic variation will be minimal if the Earth's magnetic field is stable across the journey.