Probable cause
The loss of torque on the No. 3 connecting rod’s nuts, which resulted in the failure of the No. 3 connecting rod’s bolts and a subsequent total loss of engine power due to the operator's maintenance personnel’s improper installation of the connecting rod nuts.
NTSB analysis
The private pilot reported that, during the instructional flight to accumulate flight time, the airplane experienced a rough-running engine in cruise flight and that the engine subsequently experienced a total loss of power. The pilot tried to restart the engine to no avail. He then chose to conduct a forced landing to a road, during which the airplane touched down on soft, wet ground before reaching the road. It then nosed over and came to rest inverted.
During recovery of the airplane, large cracks were noted in the engine crankcase near the No. 2 cylinder. Disassembly of the engine revealed that the crankshaft was fractured at the No. 3 connecting rod journal and exhibited signatures consistent with extreme heat. The No. 3 connecting rod bolts fractured at the point where the nuts contacted the connecting rod. Each connecting rod nut had a flat-face side and a raised-lip side. As found, the nuts were oriented with the raised-lip side touching the connecting rod despite the engine manufacturer's service instruction, which stated that "Nuts [were] to be assembled with flat face side touching the connecting rod." The caution associated with the orientation of the connecting rod nuts at installation stated that "the connecting rod bolt cannot be tightened correctly if the nut on the connecting rod is installed incorrectly." The operator's maintenance personnel likely installed the nuts incorrectly during an engine overhaul about 246 flight hours before the accident flight, which resulted in a loss of torque on the connecting rod's nuts and the subsequent fracture of the connecting rod's bolts and total loss of engine power.
Text from the NTSB. Open the NTSB docket for ERA17LA044 for the full record.
Event
- Date
- Nov 13, 2016
- Type
- Accident
- Place
- Miami, Florida
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Cessna 152
- N-number
- N94292
- Category
- Airplane
- Year built
- 1982
- Damage
- Substantial
- Operating rule
- Part 91 (general aviation)
- Purpose of flight
- Instructional
From the NTSB aviation accident database: N-registered aircraft, events since 2008, data through Oct 28, 2026. The file is published monthly, so the latest weeks are incomplete and recent records can change. The official source is the NTSB aviation investigation search. CheckAero is independent and not affiliated with the NTSB.