The Air Force has decided to destroy its entire fleet of 110 T-3A Firefly training planes, which were grounded in 1997 after crashes that killed six people.

"We critically challenged ourselves as to what was the right moral policy and economical and legal decision and were led to completely salvage these airplanes, because we no longer have a mission for this aircraft," David Smith, news division chief with Air Education and Training Command's public affairs office, told The Gazette of Colorado Springs.

The Air Force purchased the British-made, propeller-driven planes for $32 million and spent $10 million trying to make them airworthy after they were grounded. It decided to junk them rather than try to renovate them to Federal Aviation Administration standards so they could be sold.

"The aircraft has been sitting for nine years, so to get them to FAA certification you'd almost have to rebuild the airplanes," he said. "It was found to be totally cost-prohibitive."

The aerobatic Firefly went into service in 1993, replacing the T-41. Three Air Force Academy cadets and three instructors were killed in crashes.

Destruction by contractor TOTALL Metal Recycling Inc. will begin Monday and be complete by Sept. 25.