Matching Pairs AVIATION ABBREVIATIONSOnline version Match the abbreviation with the correct meaning. by Steven Rafael Torres Orozco 1 P/N 2 LB 3 SB 4 FT 5 SL 6 S/N 7 AD 8 P.S.I 9 SRM PART NUMBER FOOT POUND SERVICE LETTER STRUCTURAL REPAIR MANUAL SERIAL NUMBER SERVICE BULLETIN AIRWORTHINESS DIRECTIVE PRESSURE SQUARE INCH