As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED THE FIRST OFFICER'S SLIDING WINDOW CRACKED ON TAKEOFF AND WAS ARCING VERY BAD. FLIGHT RETURNED AND LANDED WITHOUT FURTHER INCIDENT. NO EMERGENCY WAS DECLARED. MAINTENANCE REMOVED AND REPLACED THE FIRST OFFICER'S SLIDING WINDOW PER AMM 56-12-11, ALSO REPLACED WINDOW HEAT CONTROL UNIT AS PRECAUTIONARY PER AMM 30-41-11. WINDOW HEAT OPS CHECKS NORMAL.