AN A320 WAS NOSE JACKED FOR NOSE GEAR STRUT SVCING AND HAD TAIL STABILIZING JACK IN PLACE PER THE MAINT MANUAL WITH ALARM SET. TAIL JACK ROSE 8 INCHES WITH NO ALARM. ACFT SUSTAINED MAJOR STRUCTURAL DAMAGE.

Narrative

AT APPROX XA00 I ASSISTED OTHER MECHS IN NOSE JACKING ACFT. WHEN DONE; A TAIL JACK WAS PLACED PER THE AMM; THE PROPER LOAD SET; JACK DISCONNECTED; AND THE TAIL JACK ALARM TESTED. WE LEFT THE ACFT IN A SAFE CONFIGN. AT ABOUT XA15 THE JACK WAS FOUND TO HAVE RISEN ABOUT 8 INCHES; CAUSING SUBSTANTIAL STRUCTURAL DAMAGE. I WAS TOLD THAT THE TAIL OVERWT ALARM FAILED TO SOUND; EVEN THOUGH IT WAS SET TO 1500 LBS. I WAS TOLD THE TAIL WAS UP TO 5000 LBS! TO THE BEST OF MY KNOWLEDGE; ALL SAFETY PROCS WERE FOLLOWED AND THE ACFT MAINT MANUAL AS WELL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE INSTALLATION OF THE TAIL JACK WAS ROUTINE AND THE ONLY PROB ENCOUNTERED WAS THE JACK PRELOAD WAS NOT IN THE MAINT MANUAL. 1500 LBS WAS SELECTED FOR THE PRELOAD AND THE ALARM WAS TESTED AND WORKED NORMALLY. AFTER SHIFT; THE JACK WAS FOUND TO HAVE RAISED 8 INCHES CAUSING MAJOR DAMAGE TO THE FRAMES AND STRINGERS. THE REPAIR WAS GIVEN TO THE MANUFACTURER AND A REPAIR TEAM WAS BROUGHT IN TO REPAIR THE DAMAGE.