The results of the 21st annual national Airline Quality Rating (AQR) will be announced at 9:30 a.m. EDT, Monday, April 4, at a news conference at the National Press Club, Murrow Room, in Washington, D.C.

The AQR is the most comprehensive study of the performance and quality of the 16 largest airlines in the United States. The study helps sort out the difference in airline performance for the business community, the media and the general public.

The rating is conducted annually by researchers at the W. Frank Barton School of Business at Wichita State University and the Department of Aviation Technology at Purdue University.

The rating is a multifactor look at the overall performance quality of the airlines based on elements such as on-time performance, denied boardings, mishandled baggage and customer complaints.

It is the only rating to include multiple criteria by which airline performance is measured in a quantitative and unbiased manner.

The new findings cover the 2010 calendar year. The following airlines, listed in alphabetical order, are rated: AirTran, Alaska, American, American Eagle, Atlantic Southeast, Comair, Continental, Delta, Frontier, Hawaiian, Jet Blue, Mesa, SkyWest, Southwest, United and US Airways.

Additional issues the researchers will speak to reporters about include:

— How 2010 airline performance compares to 2009.

— How on-time performance, involuntary denied boardings, mishandled bags and customer complaints have changed during the past year.

— National and international issues impacting the U.S. airline industry.

— How the airline industry has performed over the past two decades.

— How key industry elements have changed since 1991.