Airline travel continues to be problematic

Airline cancellations and delays are up slightly this year from 2013, according to data from the U.S. Department of Transportation.

The nation's biggest airline carriers averaged on-time arrivals of nearly 77.7 percent during August.  In August of 2013, that on-time arrival average was 78.8 percent.

The 14 airlines covered in the government report canceled 1.2 percent of their U.S. flights in August, up from 1 percent a year earlier.

Almost 300 flights were delayed by two hours or more. Flight delays of more than three hours can result in federal fines for an airline. The first six months of 2014 saw the worst for airline delays in six years.

The major carriers blame bad weather as a big factor for the increase. Hawaiian Airlines and Delta Air Lines had the best on-time rankings.  American Airlines and Envoy Air had the worst.

But the real trouble may still lie ahead, according to Charlie Leocha, founder of Travelers United, a non-profit consumer travel organization.

Leocha said some of the larger carriers are beginning to make their connecting times tighter at their hubs across the U.S. "The tighter that they make their connecting times, the more important their on-time arrivals are going to be."

Tighter connections will be especially problematic for flyers, according to Leocha,  because big carriers only arrive on time about 75 percent of the time, and they're flying their planes at between 85 to 90 percent capacity.

Leocha said travelers should book nonstop flights to avoid connecting flight problems, or only fly with nonstop carriers like JetBlue or Southwest.

The Associated Press contributed to this report.