Audit Reports

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Observations on the Automated Surface Observing System

Project ID: 
AV-2001-073

Summary

At the request of Senator Olympia Snowe, we reviewed FAA’s Automated Surface Observing System (ASOS), which provides pilots with weather information and has replaced human weather observers at many small, rural airports. Studies show that ASOS generally performs as well as the human weather observers the system replaced. However, we found that performance lags at airports where weather conditions can change rapidly and unexpectedly. Specific concerns include: ASOS visibility and ceiling observations; time allotted to make repairs; and the need to replace system hardware/ software to coordinate improvements among Federal agencies. We recommend that FAA revisit and finalize plans for making upgrades in ASOS to improve ceiling and visibility observations, set realistic milestones for improvements, and provide the needed resources. These improvements must be coordinated with the National Weather Service and the Department of Defense.