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

Bottom line

National Transportation Safety Board (NTSB) statistics indicate that most stall/spin accidents result when a pilot is distracted momentarily from the primary task of flying 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.