An American Airlines passenger checks the departure board for flight delays and cancellations at O’Hare International Airport. (AP Photo/Jim Prisching, File)

Associated Press | U.S. airlines operated more flights on-time in April and far fewer passengers were stuck in long tarmac delays, the government said Thursday.

The 18 airlines that report statistics to the Transportation Department were on-time 85.3 percent of the time in April, compared with a rate of 79.1 percent a year earlier and 80 percent in March. Most delays were caused by late-arriving aircraft and aviation system delays, which include bad weather, heavy traffic, or airport and air traffic system slowdowns.

U.S. Airways posted the best on-time rate among major mainline carriers. It was third in the overall rankings behind Hawaiian and Alaska Airlines. American Airlines reported the worst on-time rate of big U.S. carriers. Its sister carrier, regional airline American Eagle, was last among all airlines reporting.

Only 4 planes were stuck on the tarmac for more than three hours, down from 25 in March and 81 in April 2009. One flight, an American Airlines jet from Atlanta to Miami, was stuck for more than four hours.

But airlines didn’t cancel more flights in April to avoid tarmac delays. DOT said 3,637 flights were canceled during the month out of a total 529,330 — about half the rate in March or in April 2009. Continental grounded the fewest flights in April — just 11 out of 19,460. SkyWest Airlines canceled the most.

Airlines also did a better job of getting bags to their destinations. U.S. carriers had a mishandled baggage rate of 2.89 per 1,000 passengers in April, better than 3.89 in April a year ago and 3.72 in March.

Still, some passengers were not satisfied. DOT received 878 complaints about airline service from consumers in April, up from 782 in April 2009 but fewer complaints than in March.