Boeing 787 wing supplier Mitsubishi Heavy Industries has determined that a change in its manufacturing processes might have led to the development of hairline cracks in shear ties on Dreamliner wing ribs, Boeing confirmed Friday afternoon. The Chicago-based airframer said the problem could result in some delivery delays, but that the situation would not affect delivery guidance for 2014. Boeing recently increased production of the 787 to 10 airplanes a month.

The condition might appear in some 40 airplanes still in production, said Boeing. A company spokesman expressed confidence that the condition does not exist in any of the 787s now in service, however.

“We understand the issue, what must be done to correct it, and are completing inspections of potentially affected airplanes,” said Boeing in a statement. “We are addressing affected airplanes as required.”

It added that the affected areas “are very small” and that the time required to address the problem would vary between one and two weeks per airplane.