Boeing Co (BA.N), opens a new tab, said on Sunday that it will have to undertake further work on around 50 undeliverable 737 MAX jets, potentially postponing certain near-term deliveries, after its supplier Spirit AeroSystems (SPR.N), opens a new tab, discovered two mis-drilled holes in some fuselages.
Boeing verified the findings in response to a Reuters inquiry after industry sources reported an “edge margin,” or spacing fault, in holes drilled on the window frame of some jets.
Boeing, which has been under pressure from regulators and airlines since the Jan. 5 rupture of a door plug on a 737 MAX 9, said safety was unchanged and that existing 737s could continue flying.
“This past Thursday, a supplier notified us of a non-conformance in some 737 fuselages. I want to thank an employee at the supplier who flagged to his manager that two holes may not have been drilled exactly to our requirements,” Boeing Commercial Airplanes CEO Stan Deal said in a letter to staff referring to Spirit, which is the sole 737 fuselage supplier.
“While this potential condition is not an immediate flight safety issue and all 737s can continue operating safely, we currently believe we will have to perform rework on about 50 undelivered airplanes,” Deal said in the letter, first reported exclusively by Reuters.
Spirit spokesperson Joe Buccino told Reuters that as part of its 360-degree quality management program, a member of its team identified an issue that did not conform to engineering standards.
“We are in close communication with Boeing on this matter,” he said.
Deal stated that Boeing intends to devote several “factory days” this week at the Renton 737 plant outside Seattle to work on the misaligned holes and complete other outstanding work. Such days allow teams to suspend routine work and focus on specific projects without disrupting output.
The amount of rework time is expected to be finalized in the following days.
It is Boeing’s latest effort to improve its procedures following the blowout on Alaska Airlines (ALK.N), opening a new tab jet, which highlighted quality controls.
Investigators who have been looking into whether the bolts on the Alaska Airlines door plug were missing or improperly installed are likely to provide an interim report this week.
At the same time, Boeing has requested that a significant supplier, which it has not identified, suspend shipments until works are finished to specification, according to Deal.
“While this delay in shipment will affect our production schedule, it will improve overall quality and stability.”
Boeing stated that items that already meet the required specifications can continue to be transported.
The Federal Aviation Administration (FAA) provided no immediate reaction.
Quality Defect:
The US regulator has ordered Boeing to limit 737 manufacturing to 38 jets per month for an unspecified period while it addresses quality issues, delaying production increases required to satisfy rising demand for new jets.
So far, Boeing has stated that it will continue to buy parts from vendors at previously planned higher rates to mitigate the impact of the production expansion freeze.
The 737 MAX examinations are focusing on the potentially sloppy placing of two holes on a Spirit window frame assembly, a defect known as “short edge margin,” according to industry sources.
Edge margins, or the gap between a fastener and the edge of a metal sheet, must fulfill precise criteria meant to reduce the danger of metal fatigue in the long run.
The FAA has previously mandated inspections for cracks caused by improperly drilled fastener holes.
As of Friday, the “non-conformance” or quality fault had been discovered in 22 fuselages out of 47 inspected thus far, spread across Boeing and Spirit, and may still be present in other 737s in service, according to the sources.
The discoveries were revealed in a standard warning known as a Notice of Escapement, which requires suppliers to alert Boeing of any known or suspected quality drop, according to the sources.
Such quality assessments are routine in the aerospace industry, but the finding comes as Boeing and its best-selling airplane are under fire following the Alaska Airlines disaster.
According to a memo seen by Reuters, the US planemaker last month encouraged suppliers to tighten checks and told them it was “imperative” that they achieve quality requirements.
According to sources familiar with the situation, Boeing and Spirit have yet to reach an agreement on how many of the mis-drilled holes must be repaired and how many of the mistakes are minor enough to allow the fuselages to be used “as is.”
Spirit, which was spun out from Boeing in 2005, is scheduled to report profits on Tuesday.
Boeing 737s are constructed in Renton, outside Seattle, using fuselages shipped by train from Sprit in Wichita, Kansas.