Airline Capacity Cuts Slow in December, Some Carriers See Growth

It's really tiring seeing all those numbers in parentheses in the table below each month, no? Parentheses mean negative numbers, and that means shrinking airlines. But this month, we've seen many airlines cut less while some have even posted an increase to close out the year.

First, let's welcome Continental (CAL) and Alaska (ALK) to the positive growth club. They actually saw an increase in ASMs (the basic measure of capacity - the number of miles flown multiplied by the number of seats on board) in December as compared to December 2008. This isn't a surprise for Alaska, an airline which has really been surging lately. All those Hawai'i flights add up ASMs quickly. Continental is also in better shape than most.

We've also seen increases from several airlines when comparing December year over year versus November. JetBlue (JBLU) fell in that category with positive growth while American (AMR), Delta (DAL), and Southwest (LUV) shrank less. Curiously, some airlines that had been on a tear have actually moderated. AirTran and Allegiant (ALGT), for example, saw lower growth. Why is this the case?

Remember, December is prime leisure travel season with the holidays, so the airlines were likely running their fleets more last December than they might have during slower leisure months. (Leisure travel has held up best so far.) That makes year-over-year growth tougher.

Bringing up the rear, however, we have United (UAUA) and US Airways (LCC). They actually shrank more in December year over year than in November. It's no surprise for United. They've been shrinking their average aircraft size by parking 737s and adding smaller jets, so you would expect that to be reflected.

US Airways, however, not only shrunk more but also saw its load factor decline. AirTran was the only other airline to see a load decline. US Airways has really been trying to find itself. It's cut non-hub flights and sold off a few airplanes, so it's not a surprise that it's shrinking. Here are all the numbers. This is year-over-year change in each number December 2009 vs December 2008.