The Fort Worth Star-Telegram reports Southwest will add the Evolve interior to its 372 Boeing 737-700s. The carrier also will add it to AirTran's 737-700s and 717s as it converts them into the Southwest fleet.
The Dallas Morning News says "Southwest's older Boeing 737-500s will not be converted because they will be retired from the fleet soon. Southwest has not decided if it will retrofit the 165 Boeing 737-300s."
As for the new seats, they'll be about six pounds lighter than current seats. That, Southwest says, will be enough to save $10 million a year in fuel costs. The company also expects seat upgrades -- such as more durable tray-table latches -- will reduce maintenance costs.
Likely more noticeable to customers will be a "sleeker" seat design that Southwest says "will provide additional space under each seat for carryon luggage and approved pet carriers."
That also will allow the airline to add six extra seats to the retrofitted planes.