WASHINGTON (AP) -- Safety inspectors are not keeping up with potential risks posed by airlines trying to save money, according to a Transportation Department report Wednesday.
The problem could worsen because the Federal Aviation Administration may have fewer inspectors due to budget cuts next year, the department's inspector general said.
The FAA defended its safety record and oversight during a period when low-cost carriers expanded and traditional airlines looked for ways to cut costs.
American, United and other major carriers have lost record amounts of money and are trying to match the efficiency of low-cost competitors such as Southwest and JetBlue.
Airlines worked to get planes in and out of airports more quickly and contracted out maintenance operations, but FAA inspectors ''did not respond to industry changes in a timely and consistent manner,'' the report said.
A plane that spends less time on the ground has less time to allow its brakes to cool. Maintenance done by subcontractors receive less oversight from airlines than if the work were done in-house.
The FAA said it recognized the industry's evolution in recent years and improved the way it oversees safety.
''We changed the way we do business as the industry changed,'' said spokesman Greg Martin. As a result, ''this is the safest period in aviation history.'' There has not been a single crash in more than three years of a large passenger aircraft.
Industry spokesman Jack Evans said FAA inspections ''are secondary to the robust quality assurance programs the airlines adhere to in overseeing all maintenance work.'' Evans represents the Air Transport Association, the major airlines' industry group.
The report said it was critical that the FAA stay on top of industry changes because the agency may not have enough inspectors due to the budget cuts.
The agency is expected to lose about 300 aviation safety inspectors this year and has plans to replace only one-third of them, the report said.
''Adequate resources need to be committed to air carrier oversight to ensure the continuity of safe operations,'' said the report, signed by David Dobbs, assistant inspector general.
Peggy Gilligan, the FAA's deputy associate administrator for aviation safety, told reporters, ''Obviously we're going to have to look back at that concern.''
The report looked at five major airlines that have lost record amounts of money -- United, Delta, American, Northwest and US Airways. The FAA only stepped up its surveillance at the three that are in or near bankruptcy, the report said.
Since the terrorist attacks of Sept. 11, 2001, those five carriers retired 664 aircraft and stored 166 more and closed 42 maintenance facilities. The companies cut 9,920 pilots and 12,873 mechanics through the end of 2003.
The agency has a policy of increasing its oversight of financially troubled airlines.
Gilligan said the FAA may not need to do more inspections of an airline if it is getting smaller. But inspectors may want to make sure employees are being properly retrained for different tasks, she said.
Airlines are turning planes around faster at gates to save money and sometimes do not follow required operating procedures, the report said. FAA inspectors do not consider that practice a potential risk, the report said.
The inspector general also reviewed five low-cost airlines, noting that fast growth carries safety risks as well. They were JetBlue, ATA, AirTran, Frontier and Spirit.
One low-cost carrier, which was not identified in the report. added 56 percent more planes and nearly tripled its destinations, but reduced the number of mechanics by 14 percent, the report noted. The FAA did not identify those changes as risks, the report said.