ODI OPENED THIS PE AFTER RECEIVING THREE ALLEGATIONS OF SEAT TRACK CORROSION DISCOVERED BY FLEETS WHILE PERFORMING PREVENTATIVE MAINTENANCE.SINCE OPENING THIS INVESTIGATION, ODI HAS VISITED THE FLEETS, INSPECTED SUBJECT BUSES, INTERVIEWED SHOP PERSONNEL, REVIEWED BLUE BIRD'S RESPONSE TO OUR INFORMATION REQUEST. AND CONDUCTED A JOINT EVALUATION OF A COMPLAINT VEHICLE'S CONFORMANCE TO FMVSS 571.222, SCHOOL BUS SEATING AND CRASH PROTECTION.THE TESTING WAS CONDUCTED AT THE VEHICLE RESEARCH & TEST CENTER, ANDA BLUE BIRD BODY COMPANY TEST ENGINEER WAS IN ATTENDANCE. BASED ON THESE ACTIONS,NO SAFETY RELATED DEFECT HAS BEEN IDENTIFIED AT THIS TIME AND THIS PE IS CLOSED.THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT NO SAFETY-RELATED DEFECT EXISTS AND WE RESERVE THE RIGHT TO TAKE FURTHER ACTION IF WARRANTED.NEVERTHELESS, BLUE BIRD HAS DECIDED TO MAIL NON-SAFETY OWNER LETTERS TO THESUBJECT BUS OWNERS ADVISING THEM TO INSPECT THE ALUMINUM SEAT TRACKS ON A REGULAR BASIS AND TO MAKE ANY NECESSARY REPAIR/REPLACEMENT.