If cloud height equipment for the active runway is inoperative, under which condition may data from the inactive runway be used?

• A. Data From the Active Runway Must Be Used Regardless
• B. Data From the Inactive Runway May Be Used Only If the Active Runway’s Data Is Unreliable
• C. Data From a Distant Airport Is Preferred
• D. Data From the Inactive Runway May Be Used If Measurements Are Representative

Answer: (D)

If the instrument on the active runway is out of service, you may use the other runway’s cloud-height data only when that data accurately represents the conditions over the active runway. This means the cloud base and layer heights observed at the inactive runway are essentially the same as what would be observed at the active runway, typically due to close proximity and similar weather patterns affecting both runways. Data from a distant airport isn’t relied upon because it may not reflect local conditions, and you shouldn’t substitute unless the measurements are truly representative.