What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) While enroute from destin, Florida to tulsa, Oklahoma, at 12K feet, 30 miles se of jackson, MS., the aircraft had a slight vibration then the right propeller separated fron the engine. An emergency was declared and the aircraft landed safety at jackson. Ms. International (jan). There were six souls on board with no injuries. (.4) during cruise flight, a slight vibration was felt and the right propeller completely separated contacting the right horizontal stabilizer. The flight diverted and landed uneventfully. The right engine no. 3 cylinder connecting rod failed; evidence of exposure to elevated temperatures and higher stress fatigue crack propagation was noted. Extensive fretting noted on the faying surfaces of the right propeller gear and hub, and on both sides of the propeller bulkhead and fillet assembly. The holes in the propeller bulkhead assembly and propeller gear were elongated/eggshaped. Fatigue noted on all eight studs; wear noted on the shanks of seven studs; the eighth stud was not examined. Four of the recovered seven spacers were damaged shortening their length. Only two of the eight fractured studs were extended the s pecified minimum distance beyond the nut. No discrepancies with the threads in the hub holes of the left propeller, or to the threads in the hub holes of the right propeller that were checked. Overstress failure noted on the fractured propeller blade from the right propeller. The mechanic who installed the right propeller used un-calibrated torque wrenches and an outdated service manual. The airplane had accumulated approximately 50 hours since installation of the right propeller.
As the FAA filed it
(-23) WHILE ENROUTE FROM DESTIN, FLORIDA TO TULSA, OKLAHOMA, AT 12K FEET, 30 MILES SE OF JACKSON, MS., THE AIRCRAFT HAD A SLIGHT VIBRATION THEN THE RIGHT PROPELLER SEPARATED FRON THE ENGINE. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT LANDED SAFETY AT JACKSON. MS. INTERNATIONAL (JAN). THERE WERE SIX SOULS ON BOARD WITH NO INJURIES. (.4) DURING CRUISE FLIGHT, A SLIGHT VIBRATION WAS FELT AND THE RIGHT PROPELLER COMPLETELY SEPARATED CONTACTING THE RIGHT HORIZONTAL STABILIZER. THE FLIGHT DIVERTED AND LANDED UNEVENTFULLY. THE RIGHT ENGINE NO. 3 CYLINDER CONNECTING ROD FAILED; EVIDENCE OF EXPOSURE TO ELEVATED TEMPERATURES AND HIGHER STRESS FATIGUE CRACK PROPAGATION WAS NOTED. EXTENSIVE FRETTING NOTED ON THE FAYING SURFACES OF THE RIGHT PROPELLER GEAR AND HUB, AND ON BOTH SIDES OF THE PROPELLER BULKHEAD AND FILLET ASSEMBLY. THE HOLES IN THE PROPELLER BULKHEAD ASSEMBLY AND PROPELLER GEAR WERE ELONGATED/EGGSHAPED. FATIGUE NOTED ON ALL EIGHT STUDS; WEAR NOTED ON THE SHANKS OF SEVEN STUDS; THE EIGHTH STUD WAS NOT EXAMINED. FOUR OF THE RECOVERED SEVEN SPACERS WERE DAMAGED SHORTENING THEIR LENGTH. ONLY TWO OF THE EIGHT FRACTURED STUDS WERE EXTENDED THE S PECIFIED MINIMUM DISTANCE BEYOND THE NUT. NO DISCREPANCIES WITH THE THREADS IN THE HUB HOLES OF THE LEFT PROPELLER, OR TO THE THREADS IN THE HUB HOLES OF THE RIGHT PROPELLER THAT WERE CHECKED. OVERSTRESS FAILURE NOTED ON THE FRACTURED PROPELLER BLADE FROM THE RIGHT PROPELLER. THE MECHANIC WHO INSTALLED THE RIGHT PROPELLER USED UN-CALIBRATED TORQUE WRENCHES AND AN OUTDATED SERVICE MANUAL. THE AIRPLANE HAD ACCUMULATED APPROXIMATELY 50 HOURS SINCE INSTALLATION OF THE RIGHT PROPELLER.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.