What was found
AC WITH A PRESSURIZATION COMPLAINT. GROUND PRESSURIZATION DISCOVERED A LARGE FLOW OF AIR UNDER THE REAR CABIN FLOOR IN THE AREA OF THE OUTFLOW VALVES. FURTHER INVESTIGATION FOUND THE SUPPORT VANES FOR THE NOISE SUPPRESSORS WERE BROKEN CAUSING THE OUTFLOW VALVE TO COCK AND JAM DURING OPERATION NOT ALLOWING THE VALVE TO CLOSE COMPLETELY. CLOSE INSPECTION OF THE 3 SUPPORT VANES IS VERY IMPORTANT. THIS VALVE HAS BEEN IN THIS AC SINCE DAY ONE(20 YEARS). CLOSE INSPECTION OF THE OTHER VALVE WAS COMPLIED WITH, NO DEFECTS FOUND. NEW OUTFLOW VALVE INSTALLED, OPS CHECKED GOOD. (NE05200408329)