The first big Southwest Airlines investor wanted the new carrier to operate Boeing 707s. That plan was never really in the cards, but they did consider the Boeing 737-100, Boeing 737-200, DC-9-30, DC-9-10, BAC-111-400, and the Caravelle.

The Southwest Airlines business model was largely a copy of intra-California carrier Pacific Southwest Airlines, and PSA flew the Boeing 737-200. It made sense for PSA, so they were always going to give the Boeing 737-200 a hard look. But it was one fateful phone call with Boeing — while Southwest founding President Lamar Muse and co-founder Rollin King were meeting with the Douglas Aircraft Company — that led the airline to go with the 737.

Now they have over 750 of the aircraft. However it’s been speculated that they could look beyond the Boeing 737 for their future. In April they were visiting Europe kicking the tires on the Airbus A220. At the time this seemed like a head fake, meant to scare Boeing while the 737 MAX was grounded, in order to extract concessions from the plane manufacturer.

Swiss International Air Lines, Copyright: prestonia / 123RF Stock Photo

However Dominic Gates reports that Southwest has proposed adjusting its flight attendants union contract to allow it to fly other planes,

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.”

This may have nothing whatsoever with confidence in the Boeing 737 MAX. Addison Schonland thinks it has more do to with,

• Industry disappointment with the smaller Boeing 737 MAX 7 (of which they have 30 on order but haven’t taken delivery of yet)
  
• Need to compete with Delta’s 109-seat Airbus A220 and JetBlue founder Dave Neeleman’s airline startup Moxy which will also operate the A220

Southwest Airlines Boeing 737 MAX 8 interior

Southwest could convert their MAX 7 orders to MAX 8s, and go looking for a smaller plane that can offer lower costs for markets that can’t fill 150 seats. That could just as easily be the Embraer E2. The E190-E2 might be outfitted with 108 seats and the E195-E2 might be outfitted with 140 seats.

A deal for Boeing to take an 80% stake in Embraer’s commercial aircraft business (‘Boeing Brasil-Commercial’) should close this year. So even if Southwest expanded beyond the 737, they might still remain a 100% Boeing operator.