As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EICAS MESSAGE -HEAT WINDOW LT- DISPLAYED AFTER 1 HOUR CRUISE FLT AT FL330 AND SIMULTANEOUSLY L1 WINDOW CRACKED. PRESSURIZATION WAS NORMAL. REPLACED L1 WINDOW HEAT CONTROL UNIT IAW MM 30-41-00 OPERATION CHECK NORMAL. REMOVED AND REPLACED L1 WINDSHIELD IAW MM 56-11-01 AND OPERATION CHECK NORMAL. (M)