PHILADELPHIA (AP) _ US Airways acted reasonably when it allowed a pig to fly first class from Philadelphia to Seattle, the Federal Aviation Administration found.

Maria Tirotta Andrews brought Charlotte, her 300-pound Vietnamese potbellied pig, on the flight Oct. 17, telling the airline it was a ``therapeutic companion pet.'' Andrews said her heart condition was so severe she needed the pig to relieve stress.

``US Airways and its personnel acted in a reasonable and thoughtful manner, based on a legitimate request to transport a qualified individual with a disability and her service animal,'' said FAA spokesman Jim Peters.

Under federal rules, airlines must permit a service animal to accompany passengers to their seats.

The airline, embarrassed, filed an incident report with the FAA based on passenger complaints that the pig became unruly when the plane landed. The animal tried to enter the cockpit and refused to leave the galley until a passenger tossed food at her, according to the report.

FAA officials interviewed US Airways personnel and passengers after reading an account of the incident in the Philadelphia Daily News and decided Nov. 18 that the airline did nothing wrong, Peters said Wednesday.

Andrews denies that Charlotte behaved badly during the six-hour flight.

``My pig did not run around the plane's aisles. My pig did not run around anywhere,'' Andrews said.

She told the airline ahead of time that she would have the pig on the plane, but said it only weighed 13 pounds.

``When they saw it in Philadelphia, they said it was OK to load it on the airplane,'' Andrews said.

The airline allowed the pig into first class for free.