A PA28-235 ENG WAS STARTED THEN AFTER A FEW SECONDS SHUTDOWN. NO RESTART. FOUND R MAGNETO IMPULSE COUPLER FAILED. RPTR FAILED TO IDENT IMPULSE COUPLER AIRWORTHINESS DIRECTIVE WAS OVERDUE FOR COMPLIANCE.

Narrative

ACFT ENG WAS STARTED AND SHUT DOWN AFTER A FEW SECONDS. THEN WOULDN'T RESTART. INSPECTION DISCOVERED THE R-HAND MAGNETO IMPULSE COUPLING CAME APART. PRELIMINARY INSPECTIONS OF THE DAMAGE CANNOT DETERMINE THE EXTENT OF THE DAMAGE. THE ENG WILL BE REMOVED AND TORE DOWN FOR A COMPLETE INSPECTION. RESEARCH OF LOGBOOKS PROVED THAT THE IMPULSE COUPLING HAD APPROX 400 HRS ON IT SINCE ITS LAST INSPECTION FOR COMPLIANCE TO AIRWORTHINESS DIRECTIVE 99-04-04. I WAS THE INSPECTOR WHO PERFORMED THE LAST ANNUAL INSPECTION 8 MONTHS PRIOR AND FAILED TO IDENT THE AIRWORTHINESS DIRECTIVE WAS DUE FOR COMPLIANCE. LOOKING THROUGH THE PREVIOUS AIRWORTHINESS DIRECTIVE SEARCH FROM 4 YRS AGO FOUND THAT THE MECH WHO SIGNED OFF THE ANNUAL HAD STATED THE AIRWORTHINESS DIRECTIVE DID NOT APPLY BECAUSE OF THE 'MODEL NUMBER.' AT THAT TIME THE AIRWORTHINESS DIRECTIVE WAS NOT DUE (INSPECTION DUE EVERY 250 HRS). THE NEXT 3 ANNUALS INCLUDING THE LAST ONE WHICH I SIGNED OFF THE AIRWORTHINESS DIRECTIVE WAS DUE FOR INSPECTION AND WAS NOT IDENTED AS SUCH. THE HUMAN FACTOR THAT LED TO MY OVERSIGHT WAS THE ASSUMPTION THAT THE PREVIOUS AIRWORTHINESS DIRECTIVE SEARCH WAS CORRECT AND THE AIRWORTHINESS DIRECTIVE DID NOT APPLY. I HAVE LEARNED THAT IT IS VERY IMPORTANT TO PERFORM AN AIRWORTHINESS DIRECTIVE SEARCH FROM THE BEGINNING AND NOT TO REFER TO OTHER MECH'S STATEMENT REGARDING APPLICABILITY. FACTOR THAT CONTRIBUTES TO THE QUALITY OF PERFORMANCE WOULD BE THE AMOUNT OF TIME NEEDED TO PERFORM A COMPLETE AIRWORTHINESS DIRECTIVE SEARCH AND THE INABILITY TO CHARGE A CUSTOMER FOR THE TIME WHILE STILL PROVIDING A COMPETITIVE PRICE FOR THE COMPLETE INSPECTION. MORE DEFINED RULES AND A STANDARD OUTLINE FOR PROCS/DOCUMENTATION OF AIRWORTHINESS DIRECTIVES FROM THE FAA WOULD GREATLY REDUCE THE OCCURRENCE OF THIS TYPE OF OVERSIGHT IN THE INDUSTRY AS A WHOLE.