What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Aircraft departed calhoun county airport (kpkv) on an easterly heading for a local area flight. In cruise flight at 1100 AGL, 2300 RPM and mixture full rich, the aircraft experienced a sudden vigorous vibration; causing the propeller spinner to separate from the aircraft. Then a loud bang from the engine area with a sudden loss of power. Pilot scanned instruments and noted the oil pressure and RPM were dropping, then another bang was heard and the propeller stopped turning. Pilot then conducted and emergency landing, in a farm field resulting in minor damage to the aircraft.
Inspection of the aircraft engine revealed an approximate one inch hole/rupture of the crankcase located in the area of the number four cylinder. At the base of the cylinder there were numerous cracks in the crankcase.
Maintenance records indicate the last overhaul was signed off by an A&P mechanic holding an inspector authorization (IA) more than 24 years from date of failure. The aircraft flew approximately 710 hours during that time frame, where the last owner said he approximately flew 450 hours in the last 9 years 7 months. No log entries of proper aircraft storage or other special inspection concerning corrosion / non-operation of aircraft for extensive periods of time.
In support of NTSB request, September 12, 2016, removed number four cylinder from engine. Further inspection shows that the piston connecting rod failed in the area of the rod cap. Shipped cylinder assy. To NTSB for further inspection. FAA form 8020-2 was filled out and a copy was retained by the owner. Other copy forwarded to NTSB. SW17 office has original copy.
As the FAA filed it
AIRCRAFT DEPARTED CALHOUN COUNTY AIRPORT (KPKV) ON AN EASTERLY HEADING FOR A LOCAL AREA FLIGHT. IN CRUISE FLIGHT AT 1100 AGL, 2300 RPM AND MIXTURE FULL RICH, THE AIRCRAFT EXPERIENCED A SUDDEN VIGOROUS VIBRATION; CAUSING THE PROPELLER SPINNER TO SEPARATE FROM THE AIRCRAFT. THEN A LOUD BANG FROM THE ENGINE AREA WITH A SUDDEN LOSS OF POWER. PILOT SCANNED INSTRUMENTS AND NOTED THE OIL PRESSURE AND RPM WERE DROPPING, THEN ANOTHER BANG WAS HEARD AND THE PROPELLER STOPPED TURNING. PILOT THEN CONDUCTED AND EMERGENCY LANDING, IN A FARM FIELD RESULTING IN MINOR DAMAGE TO THE AIRCRAFT.
INSPECTION OF THE AIRCRAFT ENGINE REVEALED AN APPROXIMATE ONE INCH HOLE/RUPTURE OF THE CRANKCASE LOCATED IN THE AREA OF THE NUMBER FOUR CYLINDER. AT THE BASE OF THE CYLINDER THERE WERE NUMEROUS CRACKS IN THE CRANKCASE.
MAINTENANCE RECORDS INDICATE THE LAST OVERHAUL WAS SIGNED OFF BY AN A&P MECHANIC HOLDING AN INSPECTOR AUTHORIZATION (IA) MORE THAN 24 YEARS FROM DATE OF FAILURE. THE AIRCRAFT FLEW APPROXIMATELY 710 HOURS DURING THAT TIME FRAME, WHERE THE LAST OWNER SAID HE APPROXIMATELY FLEW 450 HOURS IN THE LAST 9 YEARS 7 MONTHS. NO LOG ENTRIES OF PROPER AIRCRAFT STORAGE OR OTHER SPECIAL INSPECTION CONCERNING CORROSION / NON-OPERATION OF AIRCRAFT FOR EXTENSIVE PERIODS OF TIME.
IN SUPPORT OF NTSB REQUEST, SEPTEMBER 12, 2016, REMOVED NUMBER FOUR CYLINDER FROM ENGINE. FURTHER INSPECTION SHOWS THAT THE PISTON CONNECTING ROD FAILED IN THE AREA OF THE ROD CAP. SHIPPED CYLINDER ASSY. TO NTSB FOR FURTHER INSPECTION. FAA FORM 8020-2 WAS FILLED OUT AND A COPY WAS RETAINED BY THE OWNER. OTHER COPY FORWARDED TO NTSB. SW17 OFFICE HAS ORIGINAL COPY.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.
Other reports on N3718X · 1
Matched to the same aircraft by N-number and date.