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