The U.S. Federal Aviation Administration recommended that Boeing address four “issues” related to manufacturing and supplier quality in a new report released on March 19. The report details the results of a joint review of the Boeing 787’s design manufacturing and assembly processes ordered after the January 2013 lithium battery fire aboard a Dreamliner parked at Boston Logan Airport. The review team also made recommendations for improved, “risk-based” FAA oversight to account for new business models.

Team members traveled to manufacturing facilities in the U.S. and abroad and used in-service data and “safety risk management principles” to conduct reviews of the 787’s critical systems. They chose specific components to examine more thoroughly, including the aircraft’s variable-frequency starter generators, electrical power panels, fuel-line couplings and aft fuselage sections.

The review team recommended, first, that Boeing establish a means to ensure suppliers identify realistic program risks and complementary mitigation plans through what it called “closed-loop flowdown validation of requirements.” Closed-loop corrective action involves a process in which suppliers define and describe the problem in question, identify causes, test, validate, implement and sustain the solutions and monitor their results. According to the report, the review team found cases in which complete and accurate design requirements did not “flow down” from Boeing to its primary supplier then to the subtier suppliers involved. The failure to adequately validate and verify design requirements resulted in inconsistency in parts manufacturing, part failures and operational disruptions such as turn backs and diversions.

Next, the FAA called on Boeing to “continue to implement and mature the gated design and production processes with sufficient resources for development programs, and to minimize risks throughout the life cycle of the program.” In such processes, engineers establish a series of “gates” at various points in the development program. Each gate contains criteria before proceeding to the next development phase. The manufacturer then must address or mitigate any unsatisfied criteria at a given gate before proceeding to the next phase. The FAA said Boeing has successfully employed a gated approach in the 737 Max, 787-9 and 767-2C programs.

The third recommendation centered on Boeing’s supply chain. Specifically, the FAA said Boeing should ensure its suppliers fully understand their integration responsibilities and accountability for subtier performance. Finally, the report said Boeing should require its suppliers to follow industry standards for the training, qualification and certification of supplier personnel performing Boeing-required (non-FAA) inspections.

Meanwhile, the FAA said it would revise its own policies, orders and procedures to ensure it conducts manufacturing surveillance at the highest-risk facilities; to assess risks related to emerging technologies, complex manufacturing processes and supply-chain management; and to make engineering conformity determinations using standardized, “risk-based” criteria.

As a result, the agency said its manufacturing inspectors will expand their review of production and quality data for critical suppliers, including those located outside the U.S. It also said it is working on a rule to strengthen the supplier reporting process for quality “issues” at all tiers of the supply chain.

Notwithstanding some of the apparent communication failures between Boeing and its suppliers, the report concluded that “the 787 meets its intended level of safety” based on the fundamental soundness of its overall design and the effective processes defined and implemented to solve problems that arose during and after certification.

In fact, the FAA determined that the 787’s reliability performance in the first 16 months of service compared favorably to the reliability of other new Boeing models over the same time period, including the 777.

For its part, Boeing said it welcomed the review and applauded the release of the report. “The findings validate our confidence in both the design of the airplane and the disciplined process used to identify and correct in-service issues as they arise,” said Boeing Commercial Airplanes president and CEO Ray Conner. “I am grateful for the hard work of the joint review team and for its recommendations, which will allow us to further improve our processes as we move forward."