Distractions, task prioritization, loss of situational awareness, or disorientation.

Bottom line

A contributing factor in many accidents is a distraction that diverts the pilot's attention from monitoring the instruments or scanning outside the aircraft. Many flight deck distractions begin as a minor problem, such as a gauge that is not reading correctly, but result in accidents as the pilot diverts attention to the perceived problem and neglects to properly control the aircraft. When a work overload situation exists, a pilot needs to stop, think, slow down, and prioritize.