I noticed a story last week in the Seattle Times (from Bloomberg) about Boeing grounding eight in-service 787 Dreamliner jets for inspection and repair. The other shoe dropped today from Dominic Gates, the Seattle Times aerospace reporter.
It turns out that there are two separate defects in the aft fuselage section and:
Boeing engineers determined that while either one of the flaws alone was not a safety of flight issue, planes with both flaws could have compromised structural integrity and had to be grounded.
Even planes with only one of the flaws may need substantial repair work during future maintenance checks to fully comply with regulatory specifications and this adds to long-standing concerns about the quality of work at Boeing’s North Charleston, SC plant. This is pretty bad timing, coming as Boeing is studying consolidating all 787 final assembly in SC. (Transferring all 787 final assembly work from Everett.)
Both the flaws are in the aft fuselage at the join of two barrel sections. One section is the back end of the pressurized cabin and the other is the tapered (unpressurized) end section where the tail is attached. Each of the flaws (when present) create gaps between the fuselage skin and the heavy bulkhead between the sections. One flaw involved incorrect sizing of the shims routinely used to fill the any gaps between skin and bulkhead that should have been flagged by software. Not clear why the SW notification “was not being used” (what does THAT phrasing really mean?). The other flaw was that in some planes the skin at the join was not smooth enough. Any deviation greater than 0.005 inches is considered outside of engineering tolerance. A plane with both flaws present would pass “limit load” requirements but might fail “ultimate load” compliance and those planes where both defects were found to be present were the ones grounded. Boeing is still analyzing what rework, if any, is needed on the other planes. (Ummm, OK then!)