The golden age of aviation may be long behind us, but according to a report released on Monday, airline performance last year was actually better than it’s been in a quarter of a century.

Researchers from Wichita State University in Kansas and Embry-Riddle Aeronautical University, a private school with campuses in Daytona Beach, Fla., and Prescott, Ariz., said in the 24th annual Airline Quality Rating report that the airline industry had improved markedly on involuntary denied boardings and customer complaints, though on-time performance and baggage handling were down slightly in 2013. The quality report is based on data collected by the U.S. Department of Transportation and annual passenger surveys.

Eight of the 15 carriers rated for performance both in 2012 and 2013 improved their scores, while just six declined. Dean Headley, associate professor of marketing at Wichita State University, said the AQR scores reflected a commendable effort by the airline industry to serve customers in a capacity-limited air travel system.

“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," he said. "With continued capacity limits and consolidation, one would hope that a less congested system would perform better.

"The challenge is whether airline performance quality improvements at this level can be maintained as more people choose to fly. Or does the infrastructure and air traffic control technology limit what the airlines can actually do?"

Headley singled out the strong performance of Delta Air Lines in 2013, saying it showed how a large, merged airline was able to compete with the typically better performing smaller carriers.

“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," he said. Yet, Delta didn't take the top slot in the 2013 AQR. That honor went to Virgin America for the second year running.

"We're honored and proud to have once again secured the top spot in the Airline Quality Rating -- a venerable ranking that is entirely based on objective and quantifiable measurements," Virgin America Chief Operating Officer Steve Forte said in a statement. "As a young airline, our goal from day one has been to reinvent flying for the better. Our teammates have shown that in addition to the innovative, award-winning guest experience we're known for, we also work hard every day to run an excellent operation and deliver on our promise to guests."

Virgin America said that 2013 was its first profitable year since the airline launched in 2007. The carrier is expected to go public sometime later this year.

Rounding out the top three in the quality report were JetBlue and Hawaiian Airlines. JetBlue was an industry leader in avoiding denied boarding incidents with a rate of just 0.001 per 10,000 passengers, while Hawaiian Airlines had the best on-time performance of all U.S. carriers at 93.3 percent.

The percentage of on-time arrivals industry-wide dropped in 2013 from 81.8 percent to 78.4 percent, while the rate of mishandled baggage increased from 3.07 per 1,000 passengers in 2012 to 3.21 per 1,000 passengers in 2013. These setbacks, however, were largely mitigated by a decline in both the number of complaints and rate of passengers who were involuntarily denied a seat.

Critics argue that while, statistically, quality may look better than it’s been in decades, 2013 was a year marked by even higher airfares, staggering ancillary fees and cramped cabins -- an airline industry model that began in 2008 and is only picking up steam.

“While airline operational performance is at an all-time record high, this does not translate to customers being happy,” Brent Bowen, Embry-Riddle Prescott dean of the College of Aviation, cautioned in the report. “Because airlines are solving operational issues and advancing in AQR elements, it is time to begin a new focus on serving travelers and expanding customer service.”

Other Findings From The Airline Quality Rating Report

-AirTran Airways experienced the largest drop in rating from No. 3 in 2012 to No. 10 in 2013.

-American Eagle had both the worst on-time performance (72.1 percent) and worst baggage-handling rate (5.9 mishandled bags per 1,000 passengers).

-SkyWest Airlines had the highest involuntary denied boarding rate at 2.55 per 10,000 passengers.

-Southwest Airlines had the lowest rate of consumer complaints (0.34 per 100,000 passengers), while Frontier Airlines had the highest (3.09 per 100,000 passengers).