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