What was found
CLIMBING THROUGH 15,500 WITH A CABIN ALT OF AT 1000 AND 5.5 PSI, A SQUEAL DEVELOPED IN THE FRONT LT SIDE WINDOW. DESCENDING REDUCED CABIN PRESSURE, SQUEAL WENT AWAY AT ABOUT 1.3 PSI. MAINTENANCE FOUND LEFT SIDE WINDOW SEAL SEPARATING, SEALED LT SIDE WINDOW IAW SAAB AMM 56-10-10-8-1. OPS CHECK GOOD.