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