What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Engine power loss struck pole and green house. Inspection revealed hole in crank case number 3 and 4 rods damaged. (.4) during a night-time flight in marginal VFR conditions, the pilot radioed approach control that his aircraft's engine had begun running rough, losing power, and he was having difficulty maintaining altitude. Approach control vectored the pilot 14 miles back to the airport where he had previously completed an instrument approach. The pilot reported the runway in sight, however, the aircraft crashed on final approach 2 miles from the runway. A witness reported hearing the aircraft's engine as it approached, followed by 5 seconds of silence, and then the sound of impact. An annual inspection was completed on the aircraft about 2 weeks before the accident and this was believed to be the owner's first flight after the inspection. During the inspection, the nos. 1, 3, and 4 cylinders were removed from the engine and repaired. Postaccident examination of the engine revealed that one of the two valve keepers had not been reinstalled on the no. 3 cylinder exha ust valve resulting in asymmetric loading of the remaining keeper. When that keeper fractures, the exhaust valve was released and entered the combustion chamber of the no. 3 cylinder where it contacted the pistion. The consequential damage fractued the nos.3 and 4 pistions, the nos. 3 and 4CONNEC ting rods, and the crankcase.
As the FAA filed it
ENGINE POWER LOSS STRUCK POLE AND GREEN HOUSE. INSPECTION REVEALED HOLE IN CRANK CASE NUMBER 3 AND 4 RODS DAMAGED. (.4) DURING A NIGHT-TIME FLIGHT IN MARGINAL VFR CONDITIONS, THE PILOT RADIOED APPROACH CONTROL THAT HIS AIRCRAFT'S ENGINE HAD BEGUN RUNNING ROUGH, LOSING POWER, AND HE WAS HAVING DIFFICULTY MAINTAINING ALTITUDE. APPROACH CONTROL VECTORED THE PILOT 14 MILES BACK TO THE AIRPORT WHERE HE HAD PREVIOUSLY COMPLETED AN INSTRUMENT APPROACH. THE PILOT REPORTED THE RUNWAY IN SIGHT, HOWEVER, THE AIRCRAFT CRASHED ON FINAL APPROACH 2 MILES FROM THE RUNWAY. A WITNESS REPORTED HEARING THE AIRCRAFT'S ENGINE AS IT APPROACHED, FOLLOWED BY 5 SECONDS OF SILENCE, AND THEN THE SOUND OF IMPACT. AN ANNUAL INSPECTION WAS COMPLETED ON THE AIRCRAFT ABOUT 2 WEEKS BEFORE THE ACCIDENT AND THIS WAS BELIEVED TO BE THE OWNER'S FIRST FLIGHT AFTER THE INSPECTION. DURING THE INSPECTION, THE NOS. 1, 3, AND 4 CYLINDERS WERE REMOVED FROM THE ENGINE AND REPAIRED. POSTACCIDENT EXAMINATION OF THE ENGINE REVEALED THAT ONE OF THE TWO VALVE KEEPERS HAD NOT BEEN REINSTALLED ON THE NO. 3 CYLINDER EXHA UST VALVE RESULTING IN ASYMMETRIC LOADING OF THE REMAINING KEEPER. WHEN THAT KEEPER FRACTURES, THE EXHAUST VALVE WAS RELEASED AND ENTERED THE COMBUSTION CHAMBER OF THE NO. 3 CYLINDER WHERE IT CONTACTED THE PISTION. THE CONSEQUENTIAL DAMAGE FRACTUED THE NOS.3 AND 4 PISTIONS, THE NOS. 3 AND 4CONNEC TING RODS, AND THE CRANKCASE.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.