Fuel System O-Ring Leaks on Post P.D.M. (Programmed Depot Maintenance) C-5A Aircraft

摘要

This report presents the data developed and gathered as a result of fuel leaks around O-rings found in C-5 fuel systems following long periods of Programmed Depot Maintenance (PDM). The O-ring leaks occured when the fuel system was refilled after having been empty for 60-90 days during PDM. The study also involved an investigation of Buna-N O-ring shrinkage and swelling characteristics along with some testing of less or no shrinkage O-ring materials like the phosphonitrilic fluoride (PNF) O-ring. (Author)