Academy aircraft return to flight Published Jan. 21, 2004 U.S. AIR FORCE ACADEMY, Colo. (AFPN) -- Forty-five aircraft previously grounded amid safety concerns were cleared for normal flight operations Jan. 17. Air Force officials regained confidence in the contract maintenance program and permanent fixes were established for all discrepancies identified.Three UV-18 Twin Otter aircraft of the 98th Flight Training Squadron, used to support the cadet parachuting program, continue on maintenance stand-down status. These aircraft will remain on the ground a few more days while new engine data download and analysis procedures are finalized.Immediately returned to flight are: TG-10B\C\D unpowered gliders and TG-14 motorgliders of the 94th FTS, and T-41s and Cessna 150s of the 557th FTS.