As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CAPTAIN`S OXYGEN MASK HARNESS LEAKING O2. SWAPPED OBSERVER OXYGEN MASK WITH CAPTAIN`S MASK IAW AMM 35-10-01. REMOVED AND REPLACED THE OBSERVER`S OXYGEN MASK WITH PILOT MASK AND INSTALLED NEW MASK INTO THE PILOT POSITION IAW AMM 35-11-12-400-801. LEAK CHECKED GOOD.