Primary altimeters must be within how many feet of field elevation?

• A. 75 feet
• B. 50 feet
• C. 100 feet
• D. 25 feet

Answer: (A)

Altitude accuracy is why this question matters. For the primary altimeter, accuracy relative to the actual field elevation is checked so the aircraft’s altitude reading reflects real height above mean sea level at the airport. The allowed difference is 75 feet, which balances typical instrument error with the need to maintain safe terrain and obstacle clearance during approaches and maneuvers near the field. If the reading strays beyond this limit, maintenance or calibration is needed. The smaller options would be stricter than required, and the larger option would permit too much discrepancy.