The Federal Aviation Administration, which oversees safety and maintenance, confirmed Thursday that it has stepped up its inspections of the Atlanta-based carrier over the past six months.

FAA officials say that the measure is preventative, and that the agency does not automatically link financial troubles with any drop in vigilance toward safety. The FAA has done this for struggling carriers dating before the 9/11 attacks.

"We do provide more oversight and conduct more inspections than we previously had," agency spokeswoman Kathleen Bergen said.

"We have certain financial criteria that once met, trigger this next step."

Delta, the nation's third largest carrier, has lost more than $5 billion in the last three years.

Delta has said bankruptcy remains a distinct possibility for the airline.

It operates its second-largest hub at the Cincinnati/Northern Kentucky International Airport.

"Delta is partnering fully with the FAA," the company said in a statement. "We welcome the opportunity to confirm our longstanding reputation as a safety-focused airline."

The new scrutiny does not apply to Delta's Erlanger-based regional subsidiary Comair, since it has an independent operating certificate. But Bergen said the agency would monitor the situation, and that Comair eventually could get increased attention as well because of its close relationship with Delta.

The agency also is keeping a closer eye on both United Airlines and US Airways, both of which are under Chapter 11 bankruptcy protection. The increased inspections include everything from checking on maintenance procedures to reviewing maintenance forms to observing in-flight procedures of both pilots and flight attendants.

"Pilots are accustomed to FAA scrutiny and are confident our professionalism will be demonstrated during this time," Delta's pilot union said in a statement.

The fact that so many carriers now are receiving extra attention worries Jim Hall, former chairman of the National Transportation Safety Board, who says that the FAA didn't have enough inspectors to begin with.

To pay closer attention to the struggling airlines, which make up more than half of the nation's market share, could leave the agency stretched too thin, said Hall, now a Washington, D.C. aviation lawyer and consultant.

"They have these struggling carriers and a lot of new entries into the market, both of which are potential red lights for safety issues, and there weren't enough inspectors to do the work required under normal times," Hall said.

Bergen said that FAA's Atlanta office, charged with overseeing Delta there, has approximately 70 full-time inspectors. Other inspectors at bases around the country, including in Louisville (which oversees Cincinnati) would help with the extra work, she said, although she would not quantify the increases in inspections that would be needed.

"We are focusing and targeting our resources toward the areas where they are needed most," Bergen said when asked if other areas could not get the attention they needed because of the extra emphasis being placed on Delta and the other carriers.

"We have systems in place for identifying areas of need that enable us to maximize use of resources, and remotely locating people around the country is one way of doing that," she said.

E-mail jpilcher@enquirer.com