Flight delays caused by airline glitches are now creating longer passenger slowdowns than congestion in the skies, a USA TODAY analysis shows.

The data call into question a long-held notion about air travel delays — that bad weather and heavy air traffic cause the bulk of the waits that passengers endure. The newspaper's analysis shows that airline problems, such as pilot shortages, taking too long to refuel and mechanical breakdowns, are as much at the root of delays as anything else.

Airline issues triggered 23.8 million minutes of delay through October this year, according to the federal Bureau of Transportation Statistics (BTS). Delays attributed to the congested air-traffic system, the next largest cause, were 23.3 million.

Overall, the number of flights delayed because of congestion was slightly higher. But the average length of delay was longer for airline-caused holdups: 55 minutes compared to 47. That was a first since data have been collected.

"It's symptomatic of an entire system out of control right now," said Darryl Jenkins, an academic and airline consultant.

Jenkins and others say that one of the chief reasons that airlines are causing more delays is that they have cut staffing dramatically to respond to the financial woes encountered after the Sept. 11 terrorist attacks. In recent months, many carriers have begun adding employees, Jenkins said.

Airlines did not dispute the BTS data, but said the system's inability to handle heavy air traffic and bad weather remain the prime causes of delays. For instance, some delays blamed on air carriers were due to weather delays earlier in the day, said David Castelveter, the spokesman for the Air Transport Association.

In recent years, most major carriers reported increases in delays caused by their own problems. Among them was Northwest Airlines, which struggled with labor problems last summer. It had more than 1.9 million minutes of such delays through October, accounting for more than 40% of all of its delays.

Northwest spokesman Roman Blahowski said the carrier may have reported delays differently than others.

The problem was more acute among regional carriers, which typically fly smaller planes under contract for the large airlines.

For example, Atlantic Southeast Airlines, which flies for Delta Air Lines, reported that 49% of its 4.7 million minutes of delay were due to the airline's operating issues. The airline did not have enough pilots to handle an increase in the schedule this year, but has aggressively hired more pilots and expects its delays to drop, said spokeswoman Kate Modolo.

Some delays attributed to regionals were the result of decisions of their major airline partners, said Roger Cohen, president of the Regional Airline Association. "Most regional carriers have little say in which flights are delayed or cancelled," Cohen said.

Unions for pilots and flight attendants said that high turnover and low staffing at regional carriers contributed to delay problems.

"It's a direct cause of the poor performance by the airlines," said Capt. John Prater, president of the Air Line Pilots Association.

Airline delays reached record levels this year.