What was found
FLT#149, JFK-GND. (AIRCRAFT PERFORMED AN AIR TURN BACK) 'CAPTAINS FIXED WINDSHIELD LOUD SQUEAL AT 9:00 POSITION. WOULD NOT SEAL AT HIGHER CABIN DIFF PRESSURE. WENT AWAY AT 5000 FT ALTITUDE WITH 2.5 PRESSURE DIFFERENTIAL; ACCOMPLISHED CAPT'N WINDSHIELD REPLACEMENT REF LOG PG 3998412-2 (INSTALLED L/H FRONT WINDSHIELD PER AMM 56-11-11 SUBTASK 56-11-11-420-062-A ON REQUIRES COMPLETION REF LOGPAGE 3998412 ITEM #1 FOR CONTINUATION) & 3998413-1. (ACCOMPLISHED WINDSHIELD INSTALLATION FROM SUBTASK 56-11-11-420-062-A TO COMPLETION. OPS CHECK WIPERS, CHECKS-OK.)'