The airline’s management has proposed new language in the contract with its flight-attendants union that would grant it the flexibility “to fly more narrowbody aircraft types.”

Southwest management told the union, TWU Local 556, in a proposal this month that the ability to operate aircraft other than the 737 “would give us the flexibility … to better compete and grow.”

“We are flying to more destinations that vary in distance, size and seasonality,” the company’s proposal states. “This change would allow us to fly aircraft types that are better suited for some of the markets we serve.”