Seattle, Chicago - Boeing says the approval delays by regulators could cause the manufacturer to suspend the production of the MAX jets.
In its letter to the U.S. Securities and Exchange Commission, Boeing referred the size of the current 737 MAX order backlog and difficulties to keep up with the planned delivery dates due to the ongoing uncertainty.
Boeing was expecting the U.S Federal Aviation Administration to lift the flight ban for its MAX jets around mid-December. But recent statements from the Agency revealed that the U.S. regulator's review of revised training requirements could go beyond December 2019.
During the Duba Air Show last month, FAA Administrator Stephen Dickson said that the Agency did not finish its audits on the aircraft's stall prevention system known as MCAS.
737 MAX's MCAS (Maneuvering Characteristics Augmentation System) is linked to two recent crashes in Indonesia and Ethiopia, which killed 346 people.
It remains to be seen whether it will be allowed to fly again by January 2020 and that a March timeline would be more conservative,
Time pressure cannot be a factor in completing safety certifications.
EASA (European Aviation Safety Agency), Transport Canada, and CAAC (Civil Aviation Administration of China) already declared that that would conduct their own reviews for the recertification of the aircraft.
Indonesia's civil aviation authority said it would allow the aircraft to return to service after all major regulators approve the changes made to the system and pilot training.
DGCA (The Directorate General of Civil Aviation of India) also announced that it was considering setting an experience threshold for pilots who will fly the 737 MAX jets of the Indian operators.
The 737 MAX is the fastest-selling aircraft in the history of Boeing, The aircraft has been grounded worldwide since March 13, after the second fatal crash in Ethiopia.
Boeing has so far recorded more than 5000 orders for its 737 MAX series jets. The manufacturer recently unveiled the 737 MAX 10, the largest variant of the series that is currently under airworthiness campaign.
Last month in Dubai Air Show, Boeing has received new 737 MAX orders after a long time. The planemaker registered 60 firm orders from three customers.