Boeing faces new delays bringing the 737 Max back, as the FAA announces it will increase its oversight of the plane even after it's cleared to fly

• The FAA plans to keep full control of certifying individual new Boeing 737 Max planes as they roll off the production line, the regulator said Tuesday.
• Normally, once the plane type is certified by the regulator, the plane maker is responsible for ensuring that individual units conform to regulatory requirements. Airlines also typically conduct inspections when taking delivery of new planes.
• Boeing's plan to begin delivering new planes to airline customers in December, before the plane was certified to fly passengers again, was cast into serious doubt.
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The FAA said on Tuesday that it planned to exercise full control over all aspects of certification of Boeing's 737 Max, even once the plane returns to commercial service.

Relatively routine activities, such as certifying individual airplanes as they roll off the production line - as opposed to certifying the overall type of plane - will be performed by FAA officials, an agency spokesperson told Business Insider.

Normally, routine day-to-day activities like certifying individual planes of an already certified type - the issuing of Airworthiness Certificates - which are among the final phases of the manufacturing process, are delegated to the planemaker.

The decision was first reported by Bloomberg.

Additionally, the likelihood of the plane being cleared to fly in 2019 was cast into further doubt, as was the possibility of Boeing resuming deliveries of completed planes to airline customers before the plane was fully cleared to reenter commercial service, according to The Air Current, an aviation industry publication.

Boeing had stated earlier this month that it expected to resume deliveries in December, and for the plane to be fully cleared to fly again in January. However, it was not clear whether airline customers would accept delivery of the plane while it was not allowed to carry passengers.

"The FAA notified Boeing today that the agency will retain authority over the issuance of Airworthiness Certificates for all newly manufactured 737 MAX aircraft," the FAA said in a statement. "This action is in line with Administrator Steve Dickson's commitment that the agency fully controls the approval process for the aircraft's safe return to service."

Individual 737 Max planes, which have already received Airworthiness Certificates, will not have to be recertified once the FAA issues a Airworthiness Directive allowing the plane to fly again.

"The FAA has not completed its review of the 737 MAX aircraft design changes and associated pilot training. The agency will not approve the aircraft for return to service until it has completed numerous rounds of rigorous testing. The FAA will take all the time it needs," the agency added.

The 737 Max has been grounded worldwide since March, following the second of two fatal crashes within five months. Both crashes have been attributed to an automated flight control system, MCAS, or the Maneuvering Characteristics Augmentation System. The two crashes killed a combined 346 people.

Boeing has been working to develop a software fix for MCAS and get approval for the plane to return to commercial service. However, the plane maker has faced numerous hurdles.

Last week, leaked e-mails showed two managers with the Canadian aviation regulator and the FAA discuss their concerns with allowing the 737 Max to return to service with the MCAS system in place.

The ongoing crisis has cost the Boeing 737 the title of best-selling airplane, allowing the Airbus A320 family to pass it in terms of numbers of orders.

US airlines have all pulled the plane from their schedules until at least early March