Starting on Saturday, we will countdown the top 10 stories as we close out the year.
First up is a few moves that Southwest Airlines made this year.
In January, the Dallas-based airline showed off a new cabin interior, called "Evolve", that had eco-friendly seats and added 6 more seats to its Boeing 737-700s. Southwest said it will cost $60 million to retrofit 372 Boeing 737-700s and it had already completed more than half of the fleet.
The seats each weigh 6 pounds less as it is made of lighter material. And with a smaller life-vest pouch, there is more room for carry-on items underneath the seat, Southwest said.
In March, with confetti cannons blasting, Southwest welcomed its newest aircraft to the fleet, it's first Boeing 737-800. The larger jet has replaced older 737s that are smaller and less fuel-efficient and is being used on longer flights out of slot-constricted airports.
Southwest has also spent most of 2012 trying to integrate AirTran Airways. And in May, it chose to shed the 88 Boeing 717 airplanes it received as part of its acquisition of AirTran.
The carrier agreed to lease the aircraft to Delta Air Lines starting in the second half of 2013 and ending in 2015. Delta said it will use the 717s to replace 50-seat regional jets and some older DC-9s that are still in service.