Boeing and the FAA investigating a third issue with the construction of Boeing 787 Dreamliner

Boeing has issued another warning about its Boeing 787 programme, advising airlines as many as 900 aircraft may need to be inspected and that there will be delays in the delivery of new Dreamliners.

Three separate production flaws over the past year have hampered efforts to turn the so-far successful Dreamliner programme into Boeing's main cash cow after its much-hyped 737 MAX aircraft was infamously grounded after two disasters.

The latest issue with the 787 Dreamliner was discovered in February and announced on Tuesday. Boeing learned during fabrication of the 787 horizontal stabiliser (also known as the tail) that some components were clamped with greater force than specified, which could result in improper gap verification and shimming. 

The Federal Aviation Administration (FAA) responded to the announcement confirming it is "investigating manufacturing flaws affecting certain Boeing 787 jetliners. The agency continues to engage with Boeing."

What is a vertical stabiliser?
What is a vertical stabiliser? Photo credit: Creative Commons/Newshub.

A person briefed on the matter told Reuters the horizontal stabiliser issue could require the inspection of as many as 900 airplanes.

Boeing said the stabiliser issue - identified at a production plant in Salt Lake City, Utah - was being corrected on airplanes not yet delivered and was not an immediate flight safety issue.

"Analysis is underway to determine if action is required on the in-service fleet," Boeing added.

Boeing shares fell 5.8 percent following the announcement. 

On Monday, the FAA said it was also investigating two other manufacturing flaws in some Boeing 787 Dreamliners, but said it was too early to say if it will require new inspections.

Boeing said in late August that airlines had removed eight 787 Dreamliners from service as a result of two distinct manufacturing issues in fuselage sections.

On Monday, Boeing also confirmed some airplanes have shims that are not the proper size, and some airplanes have areas that do not meet skin flatness specifications.

Boeing identified the shimming issue in August 2019.

"Individually these issues, while not up to specifications, still meet limit load conditions. When combined in the same location however, they result in a condition that does not meet limit load requirements," Boeing said.

Boeing confirmed the inspections will slow the timing of 787 deliveries in the near-term.

Air New Zealand, which operates 787 Dreamliners, told Newshub it has not received any recent notifications from the FAA or Boeing.