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