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(Adds details from paragraph 3) by Tim Hepher and Valerie Insinna
Boeing Co BA.N said on Sunday it would have to carry out additional work on around 50 undelivered 737 MAX planes, which could delay deliveries in the short term, after its supplier Spirit AeroSystems SPR.N discovered two poorly drilled holes on some fuselages.
Boeing confirmed the findings in response to a question from Reuters, after industry sources said a spacing issue had been discovered in holes drilled on a window frame, but the planemaker said the safety was not affected and that the existing 737s could continue to fly.
“Last Thursday, a supplier informed us of a non-compliance issue on some 737 fuselages. I would like to thank an employee of the supplier who reported to his superior that two holes may not have been drilled in accordance with our requirements,” Stan Deal, chief executive of Boeing Commercial Airplanes, said in a letter to staff.
“While this potential situation does not pose an immediate flight safety concern and all 737s can continue to operate safely, we currently believe we will need to carry out repair work on approximately 50 undelivered aircraft,” Mr. Deal said.
The checks focus on the potentially incorrect positioning of two holes on a window frame assembly supplied by Spirit, an issue known as “short edge margin,” the sources said.
As of Friday, the “non-compliance” or quality defect had been detected in 22 fuselages – almost half of the 47 inspected so far in production systems split between Boeing and Spirit – and could exist in some 737s in service, they added.
Figures provided by Deal to employees on Sunday suggest that inspections moved quickly and that the problem affects a minority of the hundreds of fuselages being manufactured.
“As part of our 360-degree quality management program, a member of our team identified an issue that is not consistent with engineering standards,” said a Spirit AeroSystems spokesperson.
The findings were revealed during a routine notification known as a “Notice of Escapement,” in which suppliers notify Boeing of any known or suspected quality deviations, the sources said.
Such quality reports are common in aerospace, but the discovery comes as Boeing and its best-selling plane face increased scrutiny after a door plug on a plane exploded mid-flight of Alaska Airlines on January 5.