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