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Audit Reports


FAA Has Not Effectively Deployed Controller Automation Tools That Optimize Benefits of Performance-Based Navigation

Requested By
Requested by the Chairmen and Ranking Members of the House Committee on Transportation and Infrastructure and the Subcommittee on Aviation
Project ID
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A cornerstone of the Federal Aviation Administration’s (FAA) Next Generation Air Transportation System is its initiative to enhance efficiency and capacity at airports through the use of performance-based navigation (PBN). However, FAA lacks the automated tools air traffic controllers need to increase PBN use and achieve benefits.

While FAA deployed Time Based Flow Management (TBFM)—an automation tool to help controllers optimize PBN operations at high altitude—it has not effectively implemented TBFM or deployed a key tool to help optimize PBN operations near airports. In addition, TBFM is not adequately meeting controllers’ needs, due in part to a lack of training and coordination, and other longstanding problems. As a result, controllers have experienced significant operational problems that hinder systemwide use of the tool.   

We made four recommendations to improve FAA’s implementation of controller automation tools and help optimize PBN operations. FAA concurred with three recommendations and partially concurred with one recommendation. Based on FAA’s response, we consider three recommendations resolved but open, and one recommendation unresolved pending receipt of an update from the Agency.


Closed on
No. 1 to FAA
Establish firm milestones and follow through with all action items required to address TBFM Study Team report recommendations and a process to account for their completion.
Closed on
No. 2 to FAA
Prioritize actions needed to complete the implementation of enhancements, including Ground Interval Management-Spacing, Terminal Sequencing and Spacing, and Path Stretch which further facilitate PBN use.
Closed on
No. 3 to FAA
Establish a NAS-wide TBFM user collaboration and information sharing database or tracking system to capture lessons learned by facilities and subject matter experts during TBFM implementation and use.
Closed on
No. 4 to FAA
Establish a process for creating agreements (e.g., Letters of Agreement), including corresponding procedures, between facilities to accommodate wider use of automation tools and establish a target date for implementing them.