BIRMINGHAM, Ala.- - The Army is trying to thin out the ranks of civilian helicopter instructor pilots at its main flight training base in Alabama with a 250-pound weight limit.

New military rules set to take effect Monday at Fort Rucker set the weight limit for instructors for a major contractor.

Court documents filed by the Army say the rule is needed partly because heavier pilots increase costs since more fuel is required to keep them aloft.

The Professional Helicopter Pilots Association Local 102, a union that represents civilian pilots at Fort Rucker, filed a federal lawsuit trying to block the new weight restriction, but a judge refused Friday to intervene, said union attorney Robert Weaver.

Aside from the union, the suit was filed by six flight instructors whose weight ranges from 252 to 272 pounds, including their flight suits and boots. None of the men would be eligible to continue working if the rule takes effect, the complaint said.

The civilian trainers work for URS Federal Support Services Inc., an Army contractor that was not named in the complaint.

Jim Bloxsom, whose weight is listed at 256 pounds in the complaint, is among the instructors who are suing. He said heftier pilots do increase fuel costs, as the Army claims, so bigger teachers are generally paired with lighter students.

Bloxsom said the new rule isn't fair because it doesn't cover instructors who work for Fort Rucker contractors other than URS or military pilots, who sometimes weigh more than 250 pounds.

Plus, Bloxsom said, he only teaches students in a ground-based simulator that doesn't require aircraft fuel.

"It shouldn't affect me in the simulator ... and it should apply to everyone across the board," he said.

Pilots who weigh 250 pounds aren't necessarily fat since many work out, Bloxsom said, but some are overweight.

The Army trains scores of helicopter pilots annually at Fort Rucker, located in the state's southeastern corner. Much of the work is performed by employees of URS, which the lawsuit said employs about 400 people as instructor pilots, teachers or support personnel.

The military told the company in September it wanted to impose the weight restriction, and URS began a weight monitoring and control program on Oct. 1, according to the complaint. The military at the time agreed to delay the limit until April 1 but still has not explained the new rule, the union claims.

The Army, in asking a judge to let the rule take effect as scheduled, said trucks are sometimes required to remove fuel from training aircraft to lighten them because of the weight of the teachers.

"Other commercial helicopter organizations maintain weight limitations of less than 250 pounds," the military argued in court documents.

Employees who weigh more than 250 pounds will be placed on paid leave for as long as they have days off to take, the suit said, but they will lose seniority after two years and won't be allowed back to work until their weight falls below 250 pounds.

The lawsuit was first reported by The Dothan Eagle.