EASA Module 11 Practice Exam

The key idea here is calibrating the magnetic compass so its readings match known magnetic headings, compensating for the aircraft’s own magnetic influences. The standard tolerance for compass swing alignment is five degrees. This gives a practical balance: readings within five degrees are generally reliable for navigation and cross-checks with other instruments, while larger discrepancies indicate the swing isn’t accurate and needs re-checking or addressing sources of deviation such as ferrous materials or electrical equipment near the compass. If the observed error exceeds five degrees, you’d re-swing or investigate and correct the cause. The other options are either too tight for routine swings or too loose to be considered acceptable for safe navigation.