Some airlines have begun giving military personnel on official travel a pass on expensive baggage fees when they carry heavy duffel bags stuffed with combat gear.

Faced with criticism from veterans groups and others that the fees are a financial burden, several airlines have announced exceptions for service members. AirTran Airways of Orlando, Fla., a subsidiary of AirTran Holdings Inc., said Friday it will waive all baggage fees for active members of the U.S. military. Earlier this week, American Airlines, Southwest Airlines Alaska Airlines and Horizon Air began waiving their fee to check a third bag for active service members.

Many airlines struggling with the high cost of jet fuel implemented or increased baggage fees this year. Some service members, including those deploying to and from combat zones, have said they've been asked to pay as much as $300 for extra or overweight duffel bags that may include body armor and other vital combat equipment.

Veterans of Foreign Wars Commander In Chief George Lisicki sent a letter earlier this month to the Air Transport Association, which represents the airline industry, asking for a break for service members. On Friday, Sen. Hillary Rodham Clinton, D-N.Y., sent a letter to six major airlines and Defense Secretary Robert Gates asking that airlines who continue to impose baggage fees bill the Pentagon directly rather than have service members pay the fees themselves.

"Members of our armed forces traveling on official orders should not have to bear any cost whatsoever associated with that official travel," Clinton said. "Our men and women in uniform deserve our utmost respect and gratitude, not additional, unnecessary paperwork."

The Pentagon reimburses service members for bag fees incurred during official travel, but not for personal travel, Defense Department spokeswoman Eileen Lainez said.