The charter airlines that transport nearly 90 percent of U.S. troops around the world had also lobbied heavily for an exemption to the new rules, saying military missions could be jeopardized. But FAA officials rejected those pleas.

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The new rules give "pilots enough time to get the rest they really need to safely get passengers to their destinations," FAA Acting Administrator Michael Huerta said.

The rules will prevent about one and a half accidents a year and an average of six deaths a year, FAA officials said. They will also improve pilots' health, officials said.

Researchers say fatigue, much like alcohol, can impair a pilot's performance by slowing reflexes and eroding judgment. The National Transportation Safety Board has been campaigning for two decades for an overhaul of pilot work schedule rules. An effort by the FAA in the late 1990s to develop new rules stalled when pilot unions and airlines were unable to find common ground.

That effort was revived after the February 2009 crash Continental Connection Flight 3407 near Buffalo. Neither pilot appeared to have slept in a bed the previous night. The flight's captain had logged onto a computer in the middle of the night from an airport crew lounge where sleeping was discouraged. The first officer had commuted overnight from Seattle to Newark, N.J., much of the time sitting in a cockpit jumpseat. They could be heard yawning on the ill-fated flight's cockpit voice recorder.

However, by a 2-1 vote the NTSB decided not to cite fatigue as a contributing factor to the crash. The board agreed that the captain's incorrect responses to a stall warning caused the accident, and that other pilot errors contributed to the crash. But investigators said it wasn't possible to determine whether those errors were the result of fatigue.

But Transportation Secretary Ray LaHood and former FAA Administrator Randy Babbitt vowed to put strong fatigue rules in place.

"We made a promise to the traveling public that we would do everything possible to make sure pilots are rested when they get in the cockpit. This new rule raises the safety bar to prevent fatigue," LaHood said in a statement.

The families of victims killed in the crash won congressional passage of a law requiring the FAA to issue new rules by Aug. 1 of this year, but the White House Office of Management and Budget delayed release of the rules.

Safety advocates applauded the new rules.

The changes replace "rules that were dangerously obsolete and completely ineffective," said Bill Voss, president of the Flight Safety Foundation in Alexandria, Va. "The rule applies fatigue science in a way that makes sense."