The Federal Aviation Administration has taken further control over certification of individual 737 Max aircraft, saying it will not allow Boeing itself to issue the airworthiness certificates that permit specific aircraft to be flown.
Boeing had previously had the ability to issue the aircraft-specific certificates under its FAA-granted organisational design approval.
Airworthiness certificates affirm that each new 737 Max is cleared to fly. The documents would be issued only after the FAA also issues an airworthiness directive, which would lift the grounding of the 737 Max fleet.
"The FAA notified Boeing today that the agency will retain authority over the issuance of airworthiness certificates for all newly manufactured 737 Max aircraft," says the FAA 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."
The FAA says the change does not affect 737 Max already delivered to customers. Operators of those aircraft, which were already issued airworthiness certificates, will need to "comply with all changes required by an FAA airworthiness directive that will be issued as part of the FAA’s requirements for return to service of those aircraft".
Asked to comment about the FAA's change, Boeing says, "We continue to work with the FAA on the safe return to service for the Max".
The FAA adds that its 737 Max work continues.
"The FAA has not completed its review of the 737 Max design changes and associated pilot training," it says. "The agency will not approve the aircraft for return-to-service until it has completed numerous rounds of rigorous testing."
Boeing has said it aims for regulators to lift the grounding before year-end.