Which cockpit instrument discrepancy is explicitly noted?

• A. Altimeter reads 100 feet high
• B. Airspeed indications on the pilot and co-pilot sides are off by 10 knots
• C. VSI shows zero climb rate
• D. Attitude indicator is reversed

Answer: (B)

Two independent airspeed indicators should align within a small tolerance. When the captain’s and the first officer’s airspeed readings differ by about 10 knots, that’s a clear anomaly pointing to a possible pitot-static or data-path issue. It signals a fault in the air data system that can affect performance calculations, autopilot speeds, and stall margins, so crews are required to explicitly note and troubleshoot it, often using standby instruments or an alternate data source and logging the discrepancy per procedure.

The other scenarios are less about a two-instrument mismatch. A single altimeter reading 100 feet high can be due to an incorrect setting and isn’t a cross-instrument discrepancy, a zero climb rate on the VSI can occur in level flight, and an attitude indicator that appears reversed would be a severe single-instrument failure that's typically obvious immediately rather than a reportable two-instrument discrepancy.