Southwest reported a great fourth quarter, up 13% over last year at the same time. As the new year starts, the compnay is still optimistic as travel bookings seem to be strong.

As the airline continues to grow, they continue to add jets. Currently, there are about 550 of the Boeing 737′s. Once they acquire AirTran, by the second quarter, they will also have some Boeing 717′s. They are working on getting more jets from Boeing, but are in the works to see if Boeing wants to revamp the 737 or build a more economic jet. Southwest would like the more economical option, but continues to wait as they make a decision.

Southwest Airlines says they are comfortable operating three types of aircraft, even though it will be quite some time before a final decision is made.

Southwest is hoping that the rise in travel continues. They are the world’s leading low fare carrier. That is going to be hard to maintain as fuel prices continue to rise.

Crude oil is refined into jet fuel. The barrels are currently $110, making it tough for airlines, but if the price jumps to a predicted $120 per barrel, that will cause real problems.

At the current price per gallon, $.80-$2.85, it will cost Southwest Airlines about $650 million more this year over last year to operate. That is a 20% percent jump over prices last year during this same time period.