What correction does the acronym UNOS represent in compass error management?

The acronym UNOS stands for "Undershoot North, Overshoot South," which is a mnemonic that helps pilots remember how to correct for magnetic compass errors when flying.

When navigating with a magnetic compass, pilots may encounter deviations caused by variations in magnetic fields due to the aircraft's movement or its environment. The compass will tend to lag when turning towards the north, causing the aircraft to undershoot its intended heading. Conversely, when turning towards the south, the compass may accelerate past the intended heading, leading to an overshoot.

Understanding and applying UNOS is crucial for pilots to ensure accurate navigation and maintain the intended flight path. By recalling this simple acronym, a pilot can quickly make the necessary corrections while in flight, ultimately enhancing the safety and effectiveness of the navigation process.