Delta Air Lines, that seemingly indomitable on-time arrival machine, managed to eke out a victory in the December on-time arrivals derby despite having to grapple with a massive power outage in the middle of the month at Atlanta Hartsfield-Jackson International, Delta's largest hub. That outage prompted the cancellation of hundreds of flights and the late arrival of many more. The December on-time arrival data showed Delta Air Lines ended December with 80.2% of its flights arriving on time for the month — a number good enough to put it in first place. One has to wonder what the final number would have been had that power outage not occurred. But despite its victory, Delta no doubt is keeping a close watch on hard-charging United Airlines, which just missed matching Delta's first-place performance in the December rankings. <br/>