Delta Air Lines was named the best airline of 2019 in the latest Airline Quality Rating (AQR), the first time the carrier has achieved the top spot in 18 years. AQR, now in its 29th year, is a research project of Wichita State University and Embry-Riddle Aeronautical University. The rankings are based on government-reported data on mishandled baggage, consumer complaints, on-time performance and involuntary denied boardings. Overall, the airlines showed general improvement with the lowest rate of bumped passengers, mishandled baggage and customer clients since the AQR started in 1991. Six of the nine airlines rated -- Delta Air Lines, Hawaiian Airlines, JetBlue Airways, Southwest Airlines, Spirit Airlines and United Airlines -- performed better in 2018, as compared with the previous year's AQR scores. Brent Bowen, AQR co-author and professor of aeronautical science at Embry-Riddle, said that despite recent reports of airlines losing the confidence of key consumers, “travelers can be confident that our airlines are improving.”