The company says Boeing found “nonconformities” in some undelivered 737 fuselages

A Boeing supplier notified the company on Thursday that it had discovered a “nonconformity” in the way some holes were drilled in about 50 undelivered 737 planes, the company said Sunday.

Some holes in the fuselage of those planes “may not have been drilled exactly to our requirements,” Stan Deal, CEO of Boeing Commercial Airplanes, said in an email to employees.

“Although this potential situation does not present an immediate flight safety issue, and all 737s can continue to operate safely, we currently believe we will have to perform a rework on approximately 50 undelivered aircraft,” Diehl said.

The Washington-based plane manufacturer has been under public scrutiny since early January, when a door seal fell off a Boeing 737 MAX 9 operated by Alaska Airlines shortly after takeoff.

The FAA said in January that it plans to increase its oversight of Boeing and begin an immediate review of Boeing's production and manufacturing.