What was found
WHILE TROUBLESHOOTING AN INTERMITTENT READY LIGHT FOR THE APU INLET DOOR, IT WAS OBSERVED THAT WHEN THE DOOR ACTUATOR RETRACTED, THE SURROUNDING STRUCTURE FLEXED. AFTER ACTUATOR REPLACEMENT, THE REMOVED ONE WAS FOUND TO BE 3/16" TOO SHORT PER THE MAINTENANCE MANUAL SPECS, WHICH WAS LOADING UP THE STRUCTURE. THIS WAS THE ORIGINAL INSTALLED PART FROM THE FACTORY. A SUBSEQUENT CHECK OF ANOTHER G550 FOUND THE SAME CONDITION. MANUFACTURER WAS NOTIFIED. APU HOURS: 625 HRS. VISUAL INSPECTION OF THE SURROUNDING STRUCTURE FOUND NO ANOMALIES.