Hawaiian Airlines was again the nation's top on-time airline in May as the industry as a whole improved its performance.

The state's largest carrier said 88.9 percent of its flights were on-time during the month. The results came despite a near 50 percent expansion in Hawaiian's interisland flight schedule because of the March 31 closure of Aloha Airlines. Hawaiian Airlines avoids many of the nation's most delay-prone airports, however, reporting flights to just 14 destinations.

Hawaiian said it was fourth among the nation's 19 largest domestic airlines for misplaced baggage and fifth for fewest flight cancellations in May.

Domestic airlines improved their on-time arrival rates in May, although more than one in five flights still failed to get passengers to their destination as scheduled, according to government data released yesterday.

Twenty-one percent of commercial flights in the U.S. arrived at least 15 minutes late, were canceled or diverted in May, according to the Transportation Department's Bureau of Transportation Statistics.

For the third month in a row, American ranked last in on-time service. Passengers on just over two-thirds of the Fort Worth, Texas-based carrier's flights — 67.3 percent — got to their destinations on time in May.

"Unfortunately, the main reasons include weather and significant (air traffic control) delays at three of our main network operating areas" in Chicago, New York, and Dallas-Fort Worth, as well as in Miami, American spokesman Tim Smith said in an e-mailed statement.

UAL Corp.'s United Airlines, the second-largest carrier, reported 72.4 percent of arrivals were on time, and Continental Airlines Inc., with 75.4 percent, rounded out the bottom of the on-time list.

U.S. carriers also improved their baggage handling in May. About 4.6 passengers out of every 1,000 reported a mishandled bag during the month.