As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CAPTAIN`S SLIDING WINDOW WAS VERY DIFFICULT TO OPEN AND CLOSE, LATCHING AND UNLATCHING REQUIRED EXCESSIVE FORCE. THE AIRCRAFT WAS GROUNDED. MAINTENANCE ADJUSTED UPPER CONTROL HOUSING IAW AMM 56-12-11, AND PERFORMED SATISFACTORY OPS CHECK.