As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 2 PACK WAS INADVERTENTLY SWITCHED ON FOR APPROX 10 MINUTES ENROUTE. PILOTS NOTICED ODOR IN COCKPIT, PACK SWITCHED OFF AND A PUFF OF WHITE SMOKE CAME OUT OF VENT IN COCKPIT THEN SMOKE ODOR DISSIPATED. MAINTENANCE REMOVED AND REPLACED RIGHT HAND AIR CYCLE MACHINE. (M)