Boeing 777X Scrutiny Is Evidence Of FAA Changes Post-MAX
A group of internal FAA subject-matter experts is reviewing aspects of the Boeing 777X at the request of senior management—the latest sign that the 737 MAX saga is changing how the FAA does business.
The Technical Advisory Board (TAB) is examining several broad areas—including human factors, airworthiness, operations, maintenance and system safety assessments (SSA)—a senior government official familiar with the project says. The tasks align with issues highlighted in a U.S. Transportation Department special committee report released in January, which made recommendations on how the agency can improve certification.
Several of them, notably increased involvement by human factors experts and more thorough scrutiny of SSAs, have been cited in other reports that, like the Transportation Department review, were prompted by two fatal 737 MAX accidents in five months. The accidents killed 346 people and led regulators to ground the fleet and review the model’s certification.
- FAA is reviewing 777X design and operations
- Agency plans for the review to be a bridge to permanent certification process changes
The FAA often uses TABs composed of agency experts not involved in the day-to-day project they are examining to look at specific certification or airworthiness issues and provide recommendations to agency staff. The FAA has a TAB reviewing some of Boeing’s proposed changes to the MAX, which remains grounded while Boeing modifies its flight control software and pilot training. Non-FAA experts are among those on the MAX TAB, which is reviewing the agency’s conclusions, including findings of compliance, related to Boeing’s proposed changes.
The 777X review team is acting more like a traditional TAB, providing advice to the FAA’s 777X certification team, and its review extends beyond design and into the operational environment. For example, the team’s review of the newest 777’s highly scrutinized folding wingtips will focus as much on human factors and operational issues such as flight deck interfaces and deicing as it does on the system’s design.
Boeing is working with the TAB, the official says, providing technical documentation and other support to members. The TAB has about 16 members and taps deeper FAA expertise on an as-needed basis.
The TAB is not on a specific schedule, and its work is not expected to affect the certification timeline of the 777-9, the first model in the new family. Two 777-9s are in flight testing, and two more are expected to join them. First deliveries are planned for next year.
In the longer term, the FAA sees the 777X TAB as a bridge to a permanent shift the agency is planning for its certification process, the official says. The change is part of the FAA’s response to the MAX reports and to a few outstanding recommendations from previous certification reviews.
The FAA’s recently released response to the Transportation Department committee report highlights several focus areas. Among them is to “approach certification holistically by treating the aircraft as complex systems, with full consideration of how all the elements in the operating system interact,” the agency wrote.
The FAA also plans to “prioritize” a long-stalled revamp of SSA rules and guidance. Launched in 2011 with the intent of adopting recommendations made by a rulemaking advisory committee and standardizing with the European Union Aviation Safety Agency, progress quickly slowed. The FAA now plans to publish a draft rule by November.
“The planned new and/or updated guidance and standards will address issues such as validating assumptions made in the system safety assessments concerning trained flight crew recognition of single and multiple failures, tracking and validating changes to key safety-related assumptions, and coordinating the manufacturer’s [safety management systems, or SMS] program with an operator’s SMS program,” the agency says.
The FAA plans to launch a policy review team in the coming weeks linked to the SSA process improvements. One of its prime areas of focus will be integrating more human factors expertise into not just SSA evaluation but into the entire certification process. The agency is recruiting at least eight human factors specialists who will be assigned to its Aircraft Evaluation Group (AEG). The AEG is the primary link between the FAA’s Aircraft Certification and Flight Standards units. A need for better coordination between the two organizations was among the issues highlighted in reviews of the MAX certification process.
In both MAX accidents, Lion Air Flight 610 in October 2018 and Ethiopian Airlines Flight 302 in March 2019, software added to the MAX that can automatically move the stabilizer in certain flight profiles activated when it was not needed. Neither crew reacted to the resulting aircraft nose-down commands as Boeing had believed they would, and both accident sequences ended in fatal dives.
Reviews of the MAX certification found that not only were Boeing’s pilot-reaction assumptions wrong, the stabilizer SSA had not been not updated after changes to the software—the Maneuvering Characteristics Augmentation System flight control law—were made late in the aircraft’s development. Some FAA experts knew about the changes, but because they were not documented in an updated SSA, key FAA engineers were left out of the loop.
Better communication might have led the FAA to order design changes that would have improved the MAX’s safety, a team of 10 regulators probing the issue concluded last October. The agency believes that more proactive involvement during certification by a broader range of experts, notably human factors specialists, will reduce the risk of similar mistakes.
One SSA-related area on which FAA pushed back is the committee’s call to remove exclusions for skill-related errors associated with manual control of the aircraft. In theory, this would force manufacturers to ensure their designs compensate for mistakes during not only complex hand-flying tasks but also routine ones such as errors on crosswind landings.
Such an approach “might be viewed as driving manufacturers toward a single solution—a fully autonomous aircraft,” the FAA says. “The FAA seeks to avoid unnecessarily limiting the range of potential solutions.”
The agency also has tasked an advisory committee to examine how certification can reasonably consider an aircraft’s global operating environment when developing operational requirements. The FAA and other regulators that certify aircraft are facing calls to develop broader training and maintenance requirements that take into account different regulatory standards, such as pilot qualification minimums, around the world, as opposed to the framework that they have established for their airlines.
The FAA says it will assign a “senior manager” to help keep the tasks outlined in its response on track and “oversee the implementation of all activities.”
Sean Broderick
Senior Air Transport & Safety Editor Sean Broderick covers aviation safety, MRO, and the airline business from Aviation Week Network’s Washington, D.C. office.