A NEW MOONEY M20TN ACCLAIM ACFT LEFT AFT TAIL CONE COMPARTMENT ACCESS PANEL WAS RE-INSTALLED BUT NOT PROPERLY SECURED. ACFT OWNER REPORTED THAT PANEL WAS MISSING AFTER ARRIVAL AT HIS DESTINATION.

Narrative

AFTER TROUBLESHOOTING THE AIRSPD GEAR SAFETY SWITCH/HOBBS METER SYS ON A MOONEY M20TN; THE L AFT TAIL CONE COMPARTMENT ACCESS PANEL WAS INSTALLED BUT NOT SECURED PROPERLY. ACFT OWNER RPTED THAT THE PANEL WAS MISSING AFTER HIS ARR AT HIS DEST. FACTORS THAT CONTRIBUTED TO THIS EVENT WERE; A PERSONAL OVERSIGHT; AND DISTRS FROM OTHER TASKS BEING PERFORMED THAT DAY. I FEEL THAT WHAT NEEDS TO BE DONE TO PREVENT THIS TYPE OF EVENT FROM HAPPENING IN THE FUTURE IS PERSONAL DUE DILIGENCE TO THE TASK AT HAND AND INCLUDING FOLLOWING OUR PROCESS OF ADDITIONAL PERSONNEL TO BE INVOLVED IN THE FINAL INSPECTION PROCESS BEFORE THE ACFT IS RETURNED TO SVC. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATES HIS COMPANY'S PROCEDURES INCLUDES DOUBLE CHECKING BY OTHER MAINT PERSONNEL FOR A FINAL ON OUTGOING ACFT. ALTHOUGH 80 % OF THE PANEL'S CAM-LOC FASTENERS WERE SECURED; THE TWO FASTENERS AT THE PANEL'S FWD EDGE WERE NOT. AS A RESULT; THE WIND CAUGHT THAT UNSECURED EDGE; LIFTED; RATTLED AND THEN TORE THE METAL PANEL OFF FROM THE FUSELAGE; LEAVING ALL THE SECURED FASTENERS IN THE FUSELAGE; EXCEPT FOR THE TWO LOOSE CAM-LOCS WHICH DEPARTED WITH THE PANEL SKIN. REPORTER ALSO STATES HE WAS DISTRACTED AS A RESULT OF A PHONE CALL AND WITH EVERYONE RUSHING TO GET THE ACFT READY FOR FLIGHT; THE DOUBLE CHECK PROCEDURE WAS NOT ACCOMPLISHED AND THE PILOT'S WALKAROUND DID NOT CATCH THE UNSECURED FASTENERS. THE AFT LEFT ACCESS PANEL WAS REMOVED SO HE COULD COMPLETE A SERVICE BULLETIN (S/B) TO REPLACE A DIODE IN THE EXTERNAL POWER RECEPTACLE IN THE AFT SECTION OF THE ACFT. REPORTER ADDS THIS ACFT IS BRAND NEW WITH G-1000 GLASS COCKPIT AND VERY FAST.