Boeing is apparently facing a new difficulty in its effort to increase 737 MAX deliveries, as the OEM and Spirit AeroSystems have reported a new manufacturing defect in a structural segment of Boeing’s top-selling aircraft. Spirit issued a statement announcing it had discovered “a quality issue involving elongated fastener holes on the aft pressure bulkhead on certain models of the 737 fuselage.”
According to that statement, Boeing has determined there is no immediate safety concern for 737 MAX jets, and that aircraft in-service fleet may continue to operate.
The aft pressure bulkhead is an airframe substructure that seals off the rear of the pressurized cabin. Spirit noted that it had implemented changes to the manufacturing process to address the error.
“We are working closely with our customer to address any impacted units within the production system and address any needed rework. Based upon what we know now, we believe there will not be a material impact to our delivery range for the year related to this issue,” according to Spirit AeroSystems’ statement.
The supplier to Spirit AeroSystems has not been named.
Not all of the aft pressure bulkhead units supplied to Boeing are defective, because Spirit relies on multiple suppliers for the affected structure. Spirt also emphasized that it will continue to deliver aft pressure bulkheads to Boeing.
Wichita-based Spirit AeroSystems is a primary supplier of aerostructures to the 737 MAX program. It has been the source of previous manufacturing issues affecting airframes for the narrow-body aircraft series.
Boeing is determined to increase the production rate for the 737 MAX, to address order backlogs but also to improve its revenues. In July it confirmed it is increasing the production rate from 31 to 38 per month by the end of 2023.
