Audit Reports

-A A +A

FAA Has Made Progress in Implementing Its Metroplex Program, but Benefits for Airspace Users Have Fallen Short of Expectations

Requested by Chairmen Bill Shuster and Frank LoBiondo of the House Committee on Transportation and Infrastructure and its Subcommittee on Aviation
Project ID: 
What We Looked At
Performance-Based Navigation (PBN) is a top investment priority for the Federal Aviation Administration (FAA) and the aviation industry under the Next Generation Air Transportation System (NextGen). PBN delivers new routes and flight procedures that primarily use satellite-based navigation aids and on-board aircraft equipment to navigate with greater precision and accuracy. To accelerate PBN, FAA began the Metroplex program in 2010 to increase efficiencies in congested, metropolitan areas with multiple airports. Chairmen Bill Shuster and Frank LoBiondo of the House Committee on Transportation and Infrastructure and its Subcommittee on Aviation requested that we examine the Metroplex program, including whether FAA has delivered new routes and procedures that yield measurable benefits to airspace users and resolved obstacles to PBN. Accordingly, our objectives were to (1) assess FAA’s progress in implementing its Metroplex program, including its efforts to resolve key barriers to PBN; (2) compare planned to actual benefits for PBN identified by FAA; and (3) assess the soundness of the methods used by FAA to estimate PBN benefits.
What We Found
FAA has made progress in implementing its Metroplex program but has experienced difficulties meeting timelines and has yet to fully resolve key obstacles. While FAA has completed 7 of 12 Metroplex locations, the Agency does not expect to complete all remaining locations until 2021, 4 years later than originally planned. Delays have occurred largely due to increased community concerns about aircraft noise. In addition, other previously identified PBN obstacles remain, including a lack of automated decision support tools for controllers, unclear terminology used by pilots and controllers for referring to flight paths, and the lengthy procedure amendment process. Further, Metroplex benefits to airspace users have fallen well short of predictions—in post‐implementation reports, FAA estimated annual benefits of $31.1 million, which is $30.5 million (49.5 percent) less than the minimum amount initially expected when FAA first planned each Metroplex site. Finally, FAA’s methods for estimating benefits overly rely on judgment and are not well documented, limiting the ability to readily test the estimates’ robustness and replicate results.
FAA concurred with all five of our recommendations. However, FAA‘s response does not meet our intent for the recommendation related to the need for better documentation, so we are asking FAA to reconsider its actions.




Closed on 03.30.2021
No. 1 to FAA

Implement a procedure for assessing online and facility-level Performance Based Navigation (PBN) training provided to controllers for effectiveness. This procedure should include reporting the results of the assessments on a continuous basis to FAA management in the PBN policy office, and take corrective action as needed.

Closed on 06.30.2021
No. 2 to FAA

Implement a process in the PBN policy office to track andevaluate whether actions taken to address identified obstacles have beeneffective in mitigating them, including the areas of phraseology, training,designing and amending procedures, and automation tools.

Closed on 07.31.2020
No. 3 to FAA

Identify the corrective actions needed to mitigate the 10 obstacles from the NextGen Advisory Committee that FAA did not include in its action plan, and if feasible, establish milestones for implementing them.

Closed on 03.05.2020
No. 4 to FAA

Display the same benefits numbers on FAA's NextGen website as those that are reported in post-implementation analysis reports for completed Metroplex sites or declare any differences in the data being reported.

Closed on 10.30.2019
No. 5 to FAA

Document the methodology used to estimate PBN benefits for each Metroplex site.