As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLIMBING OUT OF 12000 WE HEARD A LOUD SCREECHING NOISE.(NOISE SO LOUD HARD TO COMMUNICATE WITH HEADSETS ON) NOTED AIRCRAFT WAS NOT PRESSURIZING. NO OTHER INDICATIONS OBSERVED. THE NOISE WENT AWAY @3000 AND AIRSPEED OF 220KTS. NOTE THE SOUND DID NOT RETURN. FOUND THE FO'S SLIDING WINDOW DRAIN TUBE INCORRECTLY INSTALLED IN WINDOW TRACK. REPOSITIONED THE DRAIN TUBE PROPERLY.PRESSURIZED UP TO 4.5 WITH NO SQUEALS NOTED AT THIS TIME REF 56-12-11