The report conducted by researchers for Embry-Riddle Aeronautical University and Wichita State University's W. Frank Barton School of Business rated several performance markers, such as on-time flight, baggage handling and customer care services. While eight carriers upped their ranking, six took a dip and there was one newcomer to the list.
Virgin America was followed by JetBlue, in second place for the second year in a row, with Hawaiian Airlines taking up the third spot. Delta, which merged with Northwest on 2008, claimed the fourth spot.
Endeavor Air, formerly Pinnacle Airlines, was the newcomer to the list and debuted at a respectable No. 6.
The researchers said that it was unusual for a merged carrier to maintain its quality standards, making Delta an anomaly. Past reports have shown that mega-sized airlines are poor performers.
"Bigger hasn't always been better, but in Delta's case we are seeing a large airline perform at levels usually only seen by smaller low-fare carriers," said Dean Headley, associate professor of marketing at Wichita State University.
Other recent major airline mergers include American and U.S. Airways -- now the biggest airline in the world -- United and Continental and Southwest's merger with TransAir.
While industry-wide performance improved in involuntary denied boardings and customer complaints, it declined in on-time performance and baggage handling in 2013.
"When you look at the past 14 years, you find that the airline industry performs most efficiently when the system isn't stressed by high passenger volume and high number of airplanes in the air," said Headley. "With continued capacity limits and consolidation, one would hope that a less congested system would perform better."
[Airline Quality Rating 2013]