The Federal Aviation Administration intends to require airlines to inspect horizontal stabiliser hardware on Boeing 787s due to components possibly being assembled incorrectly by the company during manufacturing.
The FAA proposed the inspections in notice released on 21 November. It says Boeing already made operators aware of the issue and recommended inspections in an “Alert Requirements Bulletin” released by the company in August.
The regulator’s action responds to a report of possible “misalignment at final assembly” of horizontal stabiliser hardware – specifically, a “pivot pin lock ring, outer pivot pin and outboard spacer misalignment”.
“One operator further reported a left-side pivot assembly that did not have a visible gap between the outboard nut and trap fitting,” the FAA adds. “A misaligned pivot pin lock ring caused a pivot pin outboard spacer to not be set flush against the horizontal stabiliser pivot bearing and outboard washer.”
The result can be “decreased lateral load capacity”, possibly leading to “loss of pivot pin retention parts… [which] could result in the loss of the horizontal stabiliser.”
The FAA’s proposal would apply to 145 US-registered 787s of all three subtypes – 787-8s, 787-9s and 787-10s.
“In August, we issued detailed inspection guidance to 787-9 and 787-10 operators on how to address this issue. We fully support the FAA making that guidance mandatory, and this [notice of proposed rulemaking] extends guidance previously issued for 787-8 operators,” Boeing says. “The in-service fleet may continue to safely operate.”
Boeing recommended airlines complete the inspections within 32 months from August.
Little more is known about the issue, which comes as the US manufacturer works to improve quality and safety following a raft of manufacturing issues in recent years.
After a 45-day public comment period, the FAA intends to require operators to complete inspections detailed in Boeing’s August notice. Specifically, operators would need to inspect “the left-side and right-side horizontal stabiliser pivot pin assemblies for misalignment and incorrect gapping”, and replace components if necessary.
