ATPL: The force acting on the needle of a direct reading compass varies:
Domanda 340, General Navigation - ATPL - Airline Transport Pilot license
| Inversely with both vertical and horizontal components of the earth's magnetic field |
| Directly with the vertical component of the earth's magnetic field |
| Inversely with the horizontal component of the earth's magnetic field |
| Directly with the horizontal component of the earth's magnetic field |
