FAA Calls Into Question Boeing 737 MAX Wiring Bundles

Boeing Co. says the latest setback for the 737 MAX will not interfere with a planned mid-year return to service.

Nonetheless, the Federal Aviation Administration has notified the company that wiring bundles on the troubled aircraft are non-compliant.

The FAA formally rejected Boeing’s proposal that it not modify nor move wiring bundles in 737 MAX airplanes. Boeing says the bundles pose no threat to the flying public.

“The FAA continues to engage with Boeing as the company works to address a recently discovered wiring issue with the 737 Max,” said an FAA spokesman. “The manufacturer must demonstrate compliance with all certification standards. The aircraft will be cleared for return to passenger service only after the FAA is satisfied that all safety-related issues are addressed.”

A spokesperson for Boeing told CNBC: “We remain in ongoing discussions with the FAA on the wire bundles. Regardless of the final determination on this matter our estimate for a mid-year return to service of the MAX is unchanged.”

The 737 MAX has been grounded for almost a full year now after two separate crashes claimed the lives of 346 passengers and crew.

Boeing said any changes to the wiring bundles would take place when the company updates more than 400 Max planes that have been built but not yet delivered. The FAA’s concern with the bundles is that they could short-circuit and could, in certain situations, lead to the pilot losing control of the plane.