What was found
AT APPROXIMATELY FL160 THE FLIGHT CREW REPORTED A SQUEAL FROM THE FIRST OFFICER'S DV WINDOW SEAL. AS THE AIRCRAFT CLIMBED THE SQUEAL BECAME WORSE AND THE FLIGHT CREW LEVELED OFF AT FL210 TO KEEP THE NOISE TO A TOLERABLE LEVEL. THE FUEL LOAD ONBOARD WAS INSUFFICIENT TO CONTINUE ON TO CMH AND IT WAS DECIDED TO RETURN TO IAH FOR MAINTENANCE. THE AIRCRAFT RETURNED TO IAH AND LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE FORWARD EDGE OF THE AIRFRAME SIDE SEAL FOR THE DV WINDOW DETACHED ON THE FIRST OFFICER'S DV WINDOW. THE SEAL WAS RE-ATTACHED AND NO FURTHER DEFECTS WERE NOTED.