Southwest Airlines Co.'s pilots union stepped up its criticism of Boeing Co., saying the plane-maker may be trying to rush the return to service of its grounded 737 Max.
In a message to members, the head of the Southwest Airlines Pilots Association said Boeing should never be given the benefit of the doubt again and criticized the manufacturer's "arrogance" over the development and certification of the Max. Union president Jon Weaks also threw his support behind Southwest's decision to consider flying planes made by a company other than Boeing.
The letter deepened the tension between Boeing and the pilots of the largest operator of the Max as the aircraft's flying ban hits the eight-month mark. Southwest is the largest operator of Boeing's best-selling jet, and the grounding reduced the carrier's operating income by $435 million through September. Southwest has pulled the Max from its flight schedule through March 6 — almost a year since the jet was grounded worldwide.