A Boeing 737 Max aircraft during a display at the Farnborough International Airshow, in Farnborough
A Boeing 737 Max aircraft during a display at the Farnborough International Airshow, in Farnborough, Britain, July 20, 2022.

The top Republican on the Senate Commerce Committee has proposed extending the deadline for Boeing to win approval for two new variants of the 737 MAX until September 2024.

Boeing faces a December deadline to win approval from the Federal Aviation Administration (FAA) of the 737 MAX 7 and 10 variants, or it must meet new modern cockpit-alerting requirements that could significantly delay the planes entry into service.

Boeing shares fell 3.4% on Friday. It said it is "is focused on meeting all regulatory requirements to certify the 737-7 and 737-10" and argues it is safer to have one common 737 cockpit alerting system.

The requirements were adopted as part of a certification reform bill passed after two fatal 737 MAX crashes killed 346 people and led to the best-selling plane's 20-month grounding.

Senator Roger Wicker proposed an amendment that would extend the deadline and said he is hoping it will be attached to a must-pass annual defense bill, people briefed on the matter said. It is not year clear if Senate Commerce Committee chair Maria Cantwell and other key lawmakers agree. Wicker's office declined comment.

Wicker filed his amendment on Thursday, the same day a harsh Sept. 19 FAA letter to Boeing became public.

The FAA raised significant concerns Boeing would not be able to win certification this year and told Boeing it has not completed key work needed in order to certify the MAX 7.

Lirio Liu, the FAA's executive director of aviation safety, in the letter said the agency had told Boeing to turn in all remaining System Safety Assessments (SSAs) by mid-September "if the company intends to meet its project plan of completing certification work (and receiving FAA approval for the MAX 7) by December."

The FAA added, "most concerning, however, is that Boeing has yet to provide an initial submittal for six of the

outstanding SSAs." The FAA said the letter speaks for itself.

Boeing said in a Sept. 22 letter to the FAA that it was "hard at work to complete" required SSAs.

It said 10 were under revision by Boeing to address FAA comments in preparation for resubmittal, and that the remaining 6 were in the final stages of preparation and review prior to submittal.

On Sept. 15, Boeing Chief Executive Dave Calhoun predicted the company would win approval for the smaller 737 MAX 7 this year.