According to the FAA’s Instrument Flying Handbook, common ways pilots get their airplane into an unusual attitude include:
1. Failure to keep the airplane properly trimmed. A flight deck interruption when holding [control] pressures can easily lead to inadvertent entry into unusual attitudes.
2 Disorganized flight deck. Hunting for charts, logs, computers, etc., can seriously distract attention from the instruments.
3. Slow cross-check and fixations. The impulse is to stop and stare when noting an instrument discrepancy unless a pilot has trained enough to develop the skill required for immediate recognition.