Amid fierce opposition from charter and cargo airlines, as well as alarms raised by Pentagon officials, the Obama administration has delayed new safety rules aimed at preventing airline pilots from becoming so exhausted that they make dangerous mistakes.

The Federal Aviation Administration was supposed to have final rules in place by Aug. 1 under a law passed by Congress last year in response to a 2009 regional airline crash in western New York that killed 50 people.

The FAA proposed new rules last year designed to address long-standing concerns that pilot fatigue contributes to errors that cause accidents. They would reshape decades-old regulations governing how many hours a pilot can be on duty or at the controls of a plane, to take into account the latest scientific understanding of how fatigue slows human reflexes and erodes judgment.

Administration officials declined to comment on the reasons for the delay. A new schedule for issuing final rules indicates the target date — which has been repeatedly pushed back — is now in late November.

Charter airlines are demanding to be exempted from the new rules. Charter, also called nonscheduled, airlines not only fly tourists and sports teams, they provide the planes and pilots for thousands of military flights every year. Civilian airlines transport more than 90 percent of U.S. troops and 40 percent of military cargo around the globe under contracts with the Pentagon. The trips are frequently long, usually at night and often to danger spots like Afghanistan.

The nation's top aviation accident investigator blamed the delay in issuing final rules on the influence of airlines that put profit ahead of safety.

"There are special interests who are holding this rule up because it's not in their financial self-interest," National Transportation Safety Board Chairman Deborah Hersman told The Associated Press this week. "The American people expect safety to trump special interests, not the other way around."

The proposed rules would allow some pilots to fly more hours — 10 instead of the current maximum of eight — if they begin their day in the morning so that most of their flying takes place during the daytime. But pilots who fly overnight — the busiest time of day for cargo carriers and military charters — would be allowed fewer than eight hours because people naturally crave sleep during those hours.

The rule could force airlines to add one or two relief pilots to the normal two-pilot flight crew on long, overseas flights and to provide onboard rest facilities and sleeping accommodations at destinations more frequently.

And it sets standards for suitable resting places for a pilot during a flight while another pilot flies the plane. Airlines that provide a bunk for the pilot to lie flat for a nap would be allowed to fly longer without changing crews.

Many airlines already provide bunks for flights longer than eight hours, but not all. On United Parcel Service's Boeing 767s, pilot Lauri Esposito says the only place to rest is on a row of three small jump seats in the back of the cockpit. A captain or first officer trying to get some rest will often lie across all three seats, positioning tray tables on top to keep from sliding through the gaps, she said. If they're tall, their feet are in the bathroom.

"We're not asking for rest in heavenly beds, we just want some fatigue mitigation," said Esposito, fatigue committee chairman for the Independent Pilots Association, the union representing UPS pilots. "I don't know how these 6-foot-4 men do it. Some of them just resort to sleeping on the floor."

Airlines would also have to give pilots a minimum of nine hours off between work shifts, one hour more than currently required. They would also have to put in place "risk management" programs designed to spot work schedules likely to prevent pilots from getting adequate rest and correct them.

Airline industry officials are nearly unanimous in their opposition. The Air Transport Association, which represents large carriers, estimates the proposal will cost airlines nearly $20 billion over 10 years. The FAA pegs the cost far lower: $1.2 billion. And the agency said that would be partially offset by an estimated $660 million in benefits over the same period.

Opposition is greatest among cargo and charter carriers. UPS, the world's 9th largest airline with more than 200 planes and over 2,600 pilots, estimates its compliance costs at as much as $1.8 billion over the next decade.

"The proposal effectively rewrites UPS' collective bargaining agreement with its pilots' union while hobbling the company's finely honed domestic and overseas logistics network," the carrier said in comments to the FAA.

Air Force Gen. Duncan McNabb, commander of the U.S. Transport Command, said the current work rules for charter carriers should stay in place.

Sen. James Inhofe, R-Okla., tried to attach a provision to a long-term FAA funding bill that would have exempted charter carriers from the proposed rule, but dropped the matter for lack of support. He and Sen. Tom Coburn, R-Okla., also wrote Transportation Secretary Ray LaHood asking for an exception for charter airlines. They said FAA hadn't sufficiently considered the estimated $3.7 billion over 10 years in cost to charter carriers.

Omni Air Inc., based in Tulsa, Okla., is one of the most active charter airlines involved in military transport. It made a profit of $69 million last year on revenues of $530 million, according to the Transportation Department.

An Air Force study provided to The AP suggests that the new rules would have caused the number of flights requiring extra pilots to drop from 2,775 to 1,583 over five months last year.

But flights that don't comply with FAA regulations would have increased from 786 to 1,734 during the same period. As an example, the study said flights from Leipzig, Germany, to Fort Campbell in Kentucky will no longer be able to proceed on to Fort Hood in Texas without first changing crews in Kentucky.

The rule allows airlines to exceed pilot work limits when operating in "unsafe areas," but isn't clear on what constitutes an unsafe area, the National Air Carrier Association, which represents charter airlines, wrote the FAA. FAA rules apply to civilian pilots working overseas.

The rule "would have severe implications on the non-scheduled carriers' ability to serve U.S. military and humanitarian efforts worldwide and would ultimately weaken those efforts," the association said.

For example, under the proposed rules the carrier that currently flies from an Air Force base in Ramstein, Germany, to Al Udeid, Qatar — a flight that requires pilots to be on duty more than 17 hours — would have to increase its flight crew to four pilots and use a plane with a bunk for pilot rest, which it doesn't currently have, the association said.

Concerns that charter airlines might not be able to complete military missions aren't credible, Hersman said.

"They can still do the missions, they just need to make sure they are properly crewing and complying with the rest requirements," she said.