As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, THERE WAS AN OILY, DIRTY SOCK ODOR IN THE COCKPIT. ODOR DISSIPATED AFTER ABOUT 6000 FT, BUT CAME BACK DURING APPROACH AT ABOUT 6000 FT. ODOR WAS ALSO IN FRONT OF CABIN. INSPECTED, AND FOUND NO EXTERNALS LEAKS. REPLACED RECIRCULATION FAN FILTERS. SYSTEM OPERATION IS NORMAL.