Audit Reports

-A A +A

FAA’s Efforts To Track and Mitigate Air Traffic Losses of Separation Are Limited by Data Collection and Implementation Challenges

Requested by the Senate Committee on Commerce, Science, and Transportation and its Subcommittee on Aviation Operations, Safety, and Security and the House Committee on Transportation and Infrastructure
Project ID: 

On February 27, 2013, we issued a report on the Federal Aviation Administration’s (FAA) efforts to identify and mitigate risks of air traffic losses of separation—i.e., when two aircraft fly closer together than safety standards permit, due to an air traffic controller operational error, a pilot’s deviation,  or other issue. Between fiscal years 2009 and 2010, the number of reported operational errors by controllers increased by more than 50 percent. According to FAA, this increase was mostly due to enhanced reporting through new voluntary and automated reporting programs. However, we found that the increase was linked, in part, to a rise in actual errors, as well as other contributing factors. In addition, we found that FAA lacks an accurate baseline of the actual total number of separation losses that occur. Although FAA has recently instituted new policies and procedures for improving the collection, investigation, and reporting of separation losses, we found that the effectiveness of these procedures is limited by incomplete data and implementation challenges. Finally, FAA has recently developed new corrective action plans to mitigate high-risk separation loss events. However, it is too early to determine the effectiveness of these plans. In addition, the Agency’s corrective action plans do not include all safety risks identified by FAA and will not address all losses of separation that air traffic facility officials consider to be high risk.

FAA concurred with four and partially concurred with two of our six recommendations to improve the Agency’s policies and processes for identifying and mitigating separation losses. We are requesting that FAA provide additional information or reconsider its response for two recommendations.




Closed on 09.30.2015
No. 1 to FAA

Include all losses of separation that are reported under ATSAP, but unknown to air traffic facilities, in its official count of such events.

Closed on 03.31.2016
No. 2 to FAA

Determine the level of staff and expertise needed at the ATO Service Areas to effectively implement ATO's new Orders on investigating losses of separation, audit all TARP data, and initiate actions to fill those requirements.

Closed on 09.30.2015
No. 3 to FAA

Determine the extent to which ATO has successfully implemented its new orders (effective January 2012). This determination should include reviews of the quality of separation loss investigation reports, effectiveness of training, and additional actions or resources needed.

Closed on 12.17.2020
No. 4 to FAA

Include high-risk TCAS warning events in its Risk Analysis Process and System Risk Event Rate when the separation between two converging aircraft is maintained at 66 percent or more.

Closed on 02.03.2015
No. 5 to FAA

2. Develop actions to mitigate the following situations identified in the Risk Analysis Process: (1) poor recovery from loss of separation and (2) losses of separation involving on-the-job training.

Closed on 04.01.2013
No. 6 to FAA

3. Utilize analysis of the causal and contributory factors derived in the Risk Analysis Process—including perception, memory, and training—to identify the underlying reasons for separation losses and develop mitigation strategies to address those causes.