Ramblings

Disclaimer: I am only a paragliding hobbyist, not an aeronautical engineer nor a private or commercial pilot. No guarantee that the following is accurate. I stumbled upon magnetic compass errors in my HAGAR exam, mandatory to obtain a P3 rating and above from HPAC . The nerd in me really wanted to understand the source of these errors, especially after reading conflicting explanations from different sources and having long arguments with my mechanical engineer friends, so I had to dig deeper. This was purely out of curiosity since magnetic compasses have long been reduced to the role of calibrating gyro compasses , which do not suffer from the errors below but from divergence and need to be reset periodically from straight and level flight. And I believe the latter are themselves only used as a fallback for GPS / electronic compasses. Background Magnetic dip First you have to understand that as you leave the equator towards the magnetic poles, the force from Earth's magnetic field