C210 PLT HAD ENG PROBS DEPARTING DSM. THIS WAS CAUSED BY AN OPEN LOG ITEM.

Narrative

ON MAR/XA/01; I MADE AN EMER LNDG AT DES MOINES INTL ARPT AFTER BEING INFORMED BY THE CTL TWR SHORTLY AFTER DEP THAT MY ENG WAS SMOKING. I LANDED SAFELY BACK ON RWY 23. AN FAA ACFT SAFETY INSPECTOR INSPECTED MY ACFT AND DETERMINED THAT THE REASON FOR THE ENG FAILURE WAS THE DROP OF 500 RPM IN ONE OF THE MAGNETOS. DURING HIS INSPECTION; HE ALSO FOUND AN OPEN DISCREPANCY THAT HAD BEEN WRITTEN UP IN MAR/01 WHICH SAID 'GS ON NAV #1 INOP.' THERE WAS NO SIGNATURE ON THE DISCREPANCY AND BY THE TIME OF THIS INSPECTION; 4 OTHER PLTS HAD FLOWN THE AIRPLANE WITH THE OPEN DISCREPANCY BEFORE ME. BECAUSE THERE WAS NO SIGNATURE OR INITIALS ON THE DISCREPANCY; WE STILL DO NOT KNOW WHO WROTE IT. IT MAY OR MAY NOT HAVE BEEN A PLT; AND NO ONE HAD NOTIFIED COMPANY MAINT OR DISPATCH AS IS REQUIRED. ALSO; THE DISCREPANCY WAS WRITTEN IN THE MIDDLE OF THE LOGBOOK (BTWN PAGES) WHERE IT WAS DIFFICULT TO FIND. THIS MAY EXPLAIN WHY IT HAD NOT BEEN NOTICED BY THE OTHER 4 PLTS OR MYSELF UNTIL THE FAA INSPECTOR FOUND IT. UPON DOING MY PREFLT EARLY THAT MORNING. I HAD NOT SEEN ANY DISCREPANCY; AND DURING FLT THE GS WAS WORKING. IN THIS PARTICULAR AIRPLANE THERE ARE 2 GS'S. THEREFORE; EVEN IF 1 WERE INOPERABLE; THERE WOULD STILL BE 1 FUNCTIONING. HOWEVER; SINCE OUR COMPANY DOES NOT HAVE AN MEL; EVERYTHING IN THE AIRPLANE MUST WORK. THIS IS WHY THE FAA WANTS TO ISSUE A VIOLATION. AT THIS TIME; THE INVESTIGATION IS STILL UNDERWAY.