What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Shortly after takeodd, the pilot heard a loud bang, felt a thump, and saw the engine cowling deflect upward. He reduced engine power, and turned towards the departure airport. After a second loud bang, followed by severe vibration the pilot shut down the engine, and performed a forced landing to a field. Examintion of the wreckage revealed two holes in the top of the engine crank case which were over 8 inches in diameter. One of the engines number six cylinder connecting rod bolts showed signs of a catastrophic failure, the other number six connecting rod bolt was intact and did not contain a nut. Examinaiton of the number six connecting rod, and connecting rod bolts revealed severe mechanical impact damage to the threads of the intact bolt. The broken bolt had three different fracture features. One was consistent with failure in shear, a second was consistent with a tensile overstress seperation, and the majority of the third had rubbed appearance. The connecting rod bolts and nuts had been replaced 375 hours before the accident flight. The last annual inspection of the airplane was performed abaout 16 months prior to the accident. (.4 narrative) (-23)on climb out from Lynchburg, the engine suffered catistrophic failure of three out of six cylinders. The engine crank case was punctured which caused oil to coat the windshield. The pilot could not maintain altitude to return to Lynchburg and the off field landing was accomplished. No injuries to passengers or pilot; aircraft suffered structual damages.
As the FAA filed it
SHORTLY AFTER TAKEODD, THE PILOT HEARD A LOUD BANG, FELT A THUMP, AND SAW THE ENGINE COWLING DEFLECT UPWARD. HE REDUCED ENGINE POWER, AND TURNED TOWARDS THE DEPARTURE AIRPORT. AFTER A SECOND LOUD BANG, FOLLOWED BY SEVERE VIBRATION THE PILOT SHUT DOWN THE ENGINE, AND PERFORMED A FORCED LANDING TO A FIELD. EXAMINTION OF THE WRECKAGE REVEALED TWO HOLES IN THE TOP OF THE ENGINE CRANK CASE WHICH WERE OVER 8 INCHES IN DIAMETER. ONE OF THE ENGINES NUMBER SIX CYLINDER CONNECTING ROD BOLTS SHOWED SIGNS OF A CATASTROPHIC FAILURE, THE OTHER NUMBER SIX CONNECTING ROD BOLT WAS INTACT AND DID NOT CONTAIN A NUT. EXAMINAITON OF THE NUMBER SIX CONNECTING ROD, AND CONNECTING ROD BOLTS REVEALED SEVERE MECHANICAL IMPACT DAMAGE TO THE THREADS OF THE INTACT BOLT. THE BROKEN BOLT HAD THREE DIFFERENT FRACTURE FEATURES. ONE WAS CONSISTENT WITH FAILURE IN SHEAR, A SECOND WAS CONSISTENT WITH A TENSILE OVERSTRESS SEPERATION, AND THE MAJORITY OF THE THIRD HAD RUBBED APPEARANCE. THE CONNECTING ROD BOLTS AND NUTS HAD BEEN REPLACED 375 HOURS BEFORE THE ACCIDENT FLIGHT. THE LAST ANNUAL INSPECTION OF THE AIRPLANE WAS PERFORMED ABAOUT 16 MONTHS PRIOR TO THE ACCIDENT. (.4 NARRATIVE) (-23)ON CLIMB OUT FROM LYNCHBURG, THE ENGINE SUFFERED CATISTROPHIC FAILURE OF THREE OUT OF SIX CYLINDERS. THE ENGINE CRANK CASE WAS PUNCTURED WHICH CAUSED OIL TO COAT THE WINDSHIELD. THE PILOT COULD NOT MAINTAIN ALTITUDE TO RETURN TO LYNCHBURG AND THE OFF FIELD LANDING WAS ACCOMPLISHED. NO INJURIES TO PASSENGERS OR PILOT; AIRCRAFT SUFFERED STRUCTUAL DAMAGES.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.