By David Shepardson
WASHINGTON (Reuters) - Southwest Airlines Co said on Thursday it was postponing the return of Boeing Co's 737 MAX jets to its flight schedule until Feb. 8, the latest delay for the plane involved in two fatal crashes over five months.
The airline had previously planned to keep the jet off its flight schedule through Jan. 5. United Airlines and American Airlines have canceled flights involving the 737 MAX until January.
"With the timing of the MAX's return-to-service still uncertain, we are extending the MAX-related flight schedule adjustments through Feb. 8, 2020," Southwest said in an update on its website https://www.southwest.com/html/air/737-MAX-8.html?clk=737MAX8_190408. "The revision will proactively remove roughly 175 weekday flights from our schedule out of our total peak-day schedule of more than 4,000 daily flights."
Earlier this week, Southwest's pilots union forecast that the grounded Boeing 737 MAX airplane would return to the skies around February, weeks later than Boeing and airlines have projected.
Southwest is the largest operator of the MAX with 34 jetliners in its fleet. The aircraft was grounded worldwide following a Lion Air crash in Indonesia on Oct. 29, 2018, and an Ethiopian Airlines crash on March 10 that together killed 346 people.
The Southwest Airlines Pilots Association (SWAPA), the union for the airline's pilots, said flights would likely resume in "probably a February time frame."
Boeing said Monday it was "working towards return to service in the fourth quarter." A key step towards that effort - a certification test flight by Boeing - is not expected until at least early November.
Last week, SWAPA sued Boeing, alleging the planemaker "deliberately misled" the airline and pilots about the 737 MAX aircraft. The grounding of the 737 MAX in March forced more than 30,000 Southwest Airlines flight cancellations and caused over $100 million in lost wages for pilots, the union said.
Boeing said last week it believes the lawsuit "is meritless and will vigorously defend against it."
The union noted that following the certification test flight, the European Joint Aviation Authorities Joint Operational Evaluation Board has to submit recommendations to the FAA's Flight Standards Board.
Airlines will then submit proposed changes to the FAA Certificate Management Office and pilots must complete training.
Boeing is under pressure to deliver updated software and training to regulators for the aircraft to fly again, and the company has been negotiating compensation with customers like Southwest over the financial hit from the grounding.
Southwest, with around 10,000 pilots represented by SWAPA, had 41 more MAX jets on order for this year alone.
(Reporting by Tamara Mathias in Bengaluru; Editing by Shailesh Kuber)