Delta Air Lines ranked near the bottom for on-time performance in the airline industry in 2010, and was last among major carriers.
With 77.4 percent of its flights arriving on time last year, Atlanta-based Delta ranked 15th out of 18 carriers, according to federal data released on Thursday. Delta was fifth among the major network carriers, behind United, US Airways, Continental and American.
The airline had "a number of operational challenges throughout 2010," particularly in late spring and summer, Delta spokesman Anthony Blackacknowledged.
Delta's performance last year was worse than its 2009 effort, when 78.6 percent of its flights arrived on time and it ranked 12th out of 19 carriers, according to the U.S. Bureau of Transportation Statistics.
Last year marked the first full year that Delta combined operations with merger partner Northwest Airlines, which ranked eighth for on-time performance in 2009.
"No question, summer was tough," Delta chief executive Richard Anderson said in September, at an event for flight attendants, after several months of delays and cancellations,
At that time, Anderson said the problems over the summer stemmed from maintenance delays, from what he called a "dis-synergy with the merger," something he didn't adequately anticipate. When Delta started moving Northwest planes onto Delta routes, for example, the airline found itself unprepared when planes needed maintenance.
Delta said it has since hired more employees, added maintenance bases and increased training, the latter involving customer service. The company also will add new technology to better handle problems caused by bad weather. And its Twitter account to help passengers, DeltaAssist, will expand to a 24-hour operation starting at the end of this month, Black said.
For Delta's most lucrative customers -- frequent business travelers -- on-time performance i of utmost importance and could affect airline choice, said Brett Snyder, author of crankyflier.com. "In a place like Atlanta, does that make them consider AirTran more if Delta doesn't perform as well?" Snyder asked. "You would think probably yes."
In addition to Delta's ranking near the bottom last year, its regional subsidiary Comair came in last for on-time performance. Southwest Airlines, which plans to enter the Atlanta market by acquiring AirTran Airways, ranked 10th, and AirTran came in sixth.
Delta had the highest rate of consumer complaints to the U.S. Department of Transportation in 2010 while Southwest had the lowest.
In December, Delta encountered problems with tarmac flight delays. On Dec. 12, Delta's Miami-bound Flight 1329 was stuck on the tarmac in Detroit for three hours and 12 minutes. Delta Connection carrier Pinnacle Airlines had a tarmac delay that lasted 3:06 the same day involving a flight from Detroit to Cedar Rapids, Iowa, and theflight was canceled.
The lengthy tarmac delays are subject to investigation by the U.S. Department of Transportation, but it's unclear whether fines will be assessed, spokesman Bill Mosley said.
Airlines also are required to report animal incidents, and Delta had the highest number of animals that died or were injured during air transport last year: 16 animals died and six were injured. Six was the next-highest number of animal deaths for any other airline.