Safety Recommendation A-18-003

The FAA continues to work with Aerospace Industries Association (AIA), specifically on their “Team 003” and “Team 004,” to address Safety Recommendations A-18-3 and -4.

On June 13, 2025, Acting FAA Administrator Christopher J. Rocheleau informed us that the agency is continuing the work described in its previous letter regarding Safety Recommendations A-18-3 through -5. We look forward to receiving your next update.

-From Christopher J. Rocheleau, Acting Administrator: The Federal Aviation Administration (FAA) continues to work with the Aerospace Industries Association (AIA) teams (Team 003 and Team 004) to address these two safety recommendations. AIA Team 003 completed their ultrasonic studies and continues to review and finalize the draft forging inspection report. The team will then seek concurrence from the team members’ respective engine manufacturers before approving the report. This review took longer than anticipated, and the approval of the report is expected to occur by the end of August 2025.

Additionally, the programs associated with the improved nickel billet ultrasonic inspection and fatigue properties of nickel material anomalies have been delayed by a lack of required data and the need to complete related research and development work. The new anticipated issue date of the program reports is June 2026.

The FAA has completed a technical assessment of AIA Team 004’s report related to in-service ultrasonic inspection of engine life-limited rotating parts and its implementation. We are coordinating our review of the assessment results with the affected stakeholders, including foreign authorities, to support a harmonized approach.

We note that you continue to work with the two Aerospace Industries Association (AIA) working groups (Team 003 and Team 004) that were established to refine the enhanced inspection technologies for applications using nickel alloys. In response to Safety Recommendation A-18-3, Team 003 continues to evaluate improved ultrasonic inspection techniques for forgings during the manufacturing of nickel alloy rotating engine components. You reported that, after the team has finished evaluating inspection sensitivity to large, difficult-to-detect anomalies, it plans to complete its report summarizing the results of its research.

In response to Safety Recommendation A-18-4, in July 2023, Team 004 issued an AIA internal report titled, “In-Service Ultrasonic Inspections for Turbine Engine, Life-Limited Rotating Parts,” which documents data collected and findings from an evaluation of in-service inspections. We note that you are currently reviewing the AIA report to determine the best approach to implementing in-service ultrasonic inspections of engine-life-limited rotating components.

We continue to believe the AIA working groups’ actions thus far are responsive to both recommendations. Pending completion of their work and improved published guidance pertaining to the inspection process for nickel alloy rotating engine components, Safety Recommendation A-18-3 remains classified OPEN-- ACCEPTABLE RESPONSE. Pending a requirement to use subsurface in-service inspection techniques for critical high-energy, life-limited rotating parts for all engines, Safety Recommendation A-18-4 remains classified Open—Acceptable Response.

-From Michael G. Whitaker, Administrator: As previously noted, the Federal Aviation Administration (FAA) continues to work with the Aerospace Industries Association (AIA) to examine current methods, best practices, and potential improvements in the recommended areas over the next few years through AIA’s two working groups (“Team 003” and “Team 004”).

Team 003 (A-18-3) continues to evaluate improved ultrasonic inspection techniques for forgings during the manufacturing of nickel alloy rotating engine components. The report summarizing the results of these studies is delayed while the team finishes evaluating inspection sensitivity to large, difficult-to-detect anomalies, similar to the Chicago event. Team 003 now anticipates completing the ultrasonic studies and issuing a report for the inspection of forgings by June 2024. The reports for the programs to develop an improved nickel billet ultrasonic inspection and develop the fatigue properties of nickel material anomalies are expected to be issued in 2025.

Team 004 (A-18-4) issued an AIA internal report, In-Service Ultrasonic Inspections for Turbine Engine, Life-Limited Rotating Parts. This confidential report was issued in July 2023 and documents data collected and findings from the evaluation of in-service inspections. The FAA is currently studying the AIA report to determine the best way to implement in-service ultrasonic inspection of engine life limited rotating components by the fourth quarter of Calendar Year 2024.

These advances will lead to improved inspections of both billets and forgings during manufacturing and could also lead to subsurface in-service inspection techniques for critical high-energy, life-limited rotating parts. The FAA will continue to collaborate with the AIA teams as they work to refine the enhanced inspection technologies for applications using nickel alloys.

We note that you continue to work with the two Aerospace Industries Association (AIA) working groups (Team 003 and Team 004) that were established to refine the enhanced inspection technologies for applications using nickel alloys. In response to Safety Recommendation A-18-3, Team 003 has invited additional engine manufacturers to participate in the round-robin ultrasonic testing program and, as a result, the team has delayed publishing the industry-recommended best practice document for ultrasonic inspections of forgings.

In response to Safety Recommendation A-18-4, Team 004 is investigating additional in-service events that have been discovered and evaluating the effects of material anomalies on the fatigue properties of nickel alloys. We continue to believe the AIA working groups’ actions thus far are responsive to both recommendations. Pending our receipt and review of the groups’ evaluation of inspection technologies for use with nickel alloys, and improved guidance pertaining to the inspection process for nickel alloy rotating engine components, Safety Recommendation A-18-3 remains classified OPEN-- ACCEPTABLE RESPONSE.

Pending a requirement to use subsurface in-service inspection techniques for critical high-energy, life-limited rotating parts for all engines, Safety Recommendation A-18-4 remains classified Open—Acceptable Response.

-From Billy Nolen, Acting Administrator: As previously noted, the Federal Aviation Administration (FAA) continues to work with the Aerospace Industries Association (AIA) to examine current methods, best practices, and potential improvements in the recommended areas over the next two to three years through AIA’s established two working groups (“Team 003” and “Team 004”). Below is the current status for each team:

Team 003 (A-18-3) has continued evaluating ultrasonic inspection capabilities and improved inspection techniques for billet and forgings. The work on the industry-recommended best practice document for ultrasonic inspections of forgings is scheduled for completion by the end of December 2022, at which time the FAA will begin its analysis of the supplied data. The group experienced a short delay by including additional engine manufacturers participating in the round-robin ultrasonic testing program, which has proven to be beneficial despite the delay.

Team 004 (A-18-4) is finishing its assessment of in-service ultrasonic inspection of critical nickel and titanium rotating parts. Based on this assessment, the group expects to propose ultrasonic field inspection options by the end of December 2022, at which time the FAA will begin its analysis of the supplied data. The group experienced a short delay when it discovered additional in-service events requiring further investigation. Additionally, Team 004 continues to evaluate the effects of material anomalies on the fatigue properties of nickel alloys and remains on schedule to complete this evaluation by 2024.

We note that the two working groups (Team 003 and Team 004) that were established by the Aerospace Industries Association (AIA) are continuing their work to refine the enhanced inspection technologies for applications using nickel alloys. In response to Safety Recommendation A-18-3, Team 003 plans to develop an industry best practices document that includes the findings from its evaluation of ultrasonic inspection capabilities and improved inspection techniques for applications that use nickel alloys.

In response to Safety Recommendation A-18-4, Team 004 plans to propose ultrasonic field inspection options based on its assessment of in-service ultrasonic inspection techniques for critical nickel and titanium rotating parts.

We continue to believe your involvement in establishing the AIA working groups and the groups’ actions thus far are responsive. Pending our receipt and review of the groups’ evaluation of inspection technologies for use with nickel alloys, and improved guidance pertaining to the inspection process for nickel alloy rotating engine components, Safety Recommendation A-18-3 remains classified “Open—Acceptable Response.” Pending a requirement to use subsurface in-service inspection techniques for critical high-energy, life-limited rotating parts for all engines, Safety Recommendation A-18-4 remains classified OPEN-- ACCEPTABLE RESPONSE.

-From Steve Dickson, Administrator: In our previous response, the Federal Aviation Administration (FAA) stated that we are working with the Aerospace Industries Association (AIA) to examine current methods, best practices, and potential improvements in the recommended areas, and that the AIA had established two working groups (“Team 003” and “Team 004”) to address these recommendations. Also, as previously noted, the working groups reevaluated the tasks needed to address these recommendations and determined that this effort will take approximately three to five years to implement improvements. Below is an update for each team:

Team 003 (A-18-3) initiated activities to evaluate ultrasonic inspection capabilities and improve inspection techniques for billet and forgings, including those utilizing nickel alloys scheduled for completion in the Fall of 2021. An industry-recommended practice document for ultrasonic inspection of forgings is expected by March 2022.

Team 004 (A-18-4) is assessing in-service ultrasonic inspection of critical nickel and titanium rotating parts. Based on this assessment, the group expects to propose ultrasonic field inspection options by December 2021. The group is also evaluating the effect of material anomalies on the fatigue properties of nickel alloys scheduled for completion in 2024.

I will keep the Board informed of the FAA’s progress on these recommendations and provide an update by November 30, 2022.

We are pleased to learn that the Aerospace Industries Association (AIA) has established two working groups (Team 003 and Team 004) in response to these recommendations, and that the working groups held their first meeting in September 2019. We note that, in response to Safety Recommendation A-18-3, Team 003 is evaluating the behavior of the various nickel material anomalies under loading to determine which behaviors may contribute to nickel rotor failure and how to detect those anomalies.

We also note that, in response to Safety Recommendation A-18-4, Team 004 is developing criteria to prioritize which existing life-limited parts (LLPs) would benefit from field ultrasonic test (UT) inspections, defining a program for sample UT inspection data on time-expired LLPs, and developing UT technology for smaller engine LLPs.

We believe your work with the AIA to establish the working groups and the groups’ planned activities are responsive to these recommendations. In your next update, please provide additional details on what has been accomplished, the items to be completed, and a general timeline of the working groups’ completion of their work. Pending the completion of the working groups’ evaluation and improved guidance pertaining to the inspection process for nickel alloy rotating engine components, Safety Recommendation A-18-3 remains classified “Open—Acceptable Response.”

Pending a requirement to use subsurface in-service inspection techniques for critical high-energy, life-limited rotating parts for all engines, Safety Recommendation A-18-4 remains classified OPEN-- ACCEPTABLE RESPONSE.

-From Steve Dickson, Administrator: The Federal Aviation Administration (FAA) remains engaged with industry as they work to examine current methods, best practices, and potential improvements in the recommended areas. The Aerospace Industries Association (AIA) established two working groups to address these recommendations, and on September 10-12, 2019, the AIA groups (“Team 003” and “Team 004”) held their first face-to-face meetings. During these meetings, the groups reevaluated the tasks needed to address these recommendations and determined that this effort will take approximately three to five years to implement improvements.

Team 003 (A-18-3) will support the development of an original equipment manufacturer (OEM) capability matrix for billet and forging inspection practices. The development of this matrix will allow the group to evaluate the behavior of the various nickel material anomalies under loading. This evaluation will determine which behaviors may contribute to the failure of nickel rotors so that the detection of those anomalies can be developed using conventional and experimental techniques. Based on these efforts, analysis of this data will be ongoing and will conclude with the implementation of a technology maturation plan.

Team 004 (A-18-4) will support the development of an OEM capability matrix for existing life-limited parts (LLP) field inspections [i.e., fluorescent penetrant inspection, eddy current inspection, and ultrasonic test (UT)]. Additionally, the group will develop an industry set of criteria to prioritize which parts would benefit from field UT inspection, define a program for sample UT inspection data on time-expired LLPs, and develop the UT technology for smaller engine LLPs.

The FAA will continue to collaborate with these teams as they work to refine the enhanced inspection technologies for applications using nickel alloys.

I will keep the Board informed of the FAA’s progress on these recommendations and provide an update by September 30, 2021.

We note that you regularly meet with engine and rotor grade material manufacturers as part of the Aerospace Industries Association’s (AIA’s) Rotor Integrity Steering Committee and the Jet Engine Titanium Quality Committee, and that you plan to address these recommendations as part of your meetings and discussions with these groups. Based on these discussions with industry, you plan to revise your policies requiring ultrasonic inspection techniques during manufacturing or in service for engine rotor life-limited parts, as needed.

Pending your evaluation of inspection technologies for use with nickel alloys, and improved guidance pertaining to the inspection process for nickel alloy rotating engine components, Safety Recommendation A 18 3 is classified OPEN--ACCEPTABLE RESPONSE. Pending a requirement to use subsurface in-service inspection techniques for critical high-energy, life-limited rotating parts for all engines, Safety Recommendation A-18 4 is classified “Open—Acceptable Response.”

-From Daniel K. Elwell, Acting Administrator: The Federal Aviation Administration (FAA) meets regularly with engine and rotor grade material manufacturers as part of the Aerospace Industries Association (AIA) Rotor Integrity Steering Committee (RISC) and Jet Engine Titanium Quality Committee (JETQC). We plan to include recommendations A-18-03 and A-1 8-04 as part of our discussions with the AJA RISC and JETQC to determine the appropriate actions and response to these recommendations.

Based on our discussions with industry, the FAA will consider the need for policy requiring ultrasonic inspection techniques during manufacturing or in-service for engine rotor life -limited parts.

On January 30, 2018, the NTSB adopted its report Uncontained Engine Failure and Subsequent Fire, American Airlines Flight 383, Boeing 767-323, N345AN, Chicago, Illinois, October 28, 2016, AAR1801. The details of this accident investigation and the resulting safety recommendations may be found in the attached report, which can also be accessed at http://www.ntsb.gov. Among the Safety Recommendations seven are issued to Federal Aviation Administration, which can be found on page 77 of the report. The NTSB is vitally interested in these recommendations because they are designed to prevent accidents and save lives.

We would appreciate a response within 90 days, detailing the actions you have taken or intend to take to implement these recommendations. When replying, please refer to the safety recommendations by number.