As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: HIGH PITCH SQUEAL COMING FROM FIRST OFFICERS SLIDING WINDOW, FROM FL 240 IN THE CLIMB AND IN CRUISE FL380. DIFF PRESS 8.0 PSI. ALL INDICATIONS NORMAL, MAINTENAANCE REPLACED THE SLIDING WINDOW PER AMM 52-12-11. A SATISFACTORY LEAK/ OPERATIONAL CHECK WAS ACCOMPLISHED.