American Airlines on Saturday received clearance from federal aviation officials to return all of its 300 grounded jets to service, an airline spokesman said. After 200 cancellations Saturday morning, Fort Worth-based American was running a full schedule by the afternoon with no cancellations, said spokesman Charley Wilson. Starting Tuesday, the nation's largest airline canceled nearly 3,300 flights, as it grounded 300 MD-80 jets to wrap wiring bundles to meet federal safety standards and prevent fires. The cancellations stranded hundreds of thousands of people during the week. American said 226 of its MD-80s were back in service by Friday morning. By noon on Saturday, the airline had received clearance to return all the remaining grounded jets to service, Wilson said. The groundings had come as a surprise. American officials said they thought they had the needed repair work completed two weeks ago when it scrubbed more than 400 flights, but the Federal Aviation Administration said the wiring still was not secured and stowed properly in wheel wells. Gerard Arpey, chairman and chief executive of American parent AMR Corp., said the costs of the cancellations to American will run into the tens of millions of dollars – including vouchers to reimburse stranded customers. __