What was found
MUSTY, OILY, DIRTY SOCK ODOR AFTER TAKEOFF, AND DESCENT, UNTIL 15,000 - 18,000 FT. THE ODOR WAS ISOLATED TO COCKPIT AREA. ODOR DISSIPATES WHEN PACK NR 1 OFF. RETURNS WHEN PLACED ON. ODOR PRESENT WHEN NR 1 HP VALVE OPEN, ODOR NOT RELATED TO APU. FUMES BEGAN 30,000 FT START OF DESCENT, UNTIL TOUCH DOWN. FUMES PRESENT WHILE PACK NR 1 ON. FUMES DISSIPATE WHEN PACK NR 1 SELECTED OFF. COMPLIED WITH AN ENGINE COMPARTMENT WASH AND PERFORMED A PACK DECONTAMINATION IAW AMM 21-00-00-615-009A. PERFORMED AN OPS CHECK OF THE PACK NR 1 WITH ENGINE NR 1, OPS CHECKED OK. DIRTY SOCK ODOR NOT PRESENT IN ACFT.