Less than a month after pilots at US Airways took out a full-page ad in USA Today accusing the carrier of skimping on fuel loads to save money, pilots at other airlines are continuing to sound the alarm and are expressing concerns about the safety of airline crews and passengers.

Pilots said that their airline bosses, desperate to cut costs, are forcing them to fly uncomfortably low on fuel. The situation got bad enough three years ago, even before the latest surge in fuel prices, that NASA sent a safety alert to federal aviation officials. Since then, pilots, flight dispatchers and others have continued to sound off with their own warnings, yet the Federal Aviation Administration says there is no reason to order airlines to back off their effort to keep fuel loads to a minimum.

“We can’t dabble in the business policies or the personnel policies of an airline,” FAA spokesman Les Dorr said recently. He added that there was no indication safety regulations were being violated.

The September 2005 safety alert was issued by NASA’s confidential Aviation Safety Reporting System, which allows air crews to report safety problems without fear their names will be disclosed.

With fuel prices now their biggest cost, airlines are aggressively enforcing new policies designed to reduce consumption.

In February, a Boeing 747 captain reported running low on fuel en route to Kennedy Airport. He said he continued on to Kennedy after consulting his airline’s operations manager, who told him there was adequate fuel aboard the jet.

When the plane arrived, the captain said it had so little fuel that had there been any delay in landing, “I would have had to declare a fuel emergency” – a term that tells air traffic controllers a plane needs immediate priority to land.

The last major U.S. air crash attributed to low fuel was on Jan. 25, 1990, when an Avianca Boeing 707 ran out while waiting to land at Kennedy and crashed in Cove Neck. Seventy-three of 158 aboard were killed.