At 9,000 feet, what is the maximum pilot/copilot altitude difference?

• A. 50 feet
• B. 55 feet
• C. 60 feet
• D. 70 feet

Answer: (C)

Two independent altitude readings must stay very close so both pilots share the same awareness of the aircraft’s height. The altimeters can drift apart due to instrument error, incorrect settings, or a failure, so a tight tolerance is set to catch discrepancies early.

At 9,000 feet, the maximum allowed pilot/copilot altitude difference is 60 feet. This limit provides a safety margin to ensure both crew members are seeing essentially the same altitude and to prompt corrective action (rechecking or re-setting altimeters) if the difference grows beyond that. If the readings diverge beyond 60 feet, it indicates a potential instrument or setting issue that must be addressed before continuing.