ERA18FA137 · Piper PA28R 200
Piper PA28R 200 · Accident: loss of engine power (partial) en route
From Gwinnett County Briscoe Field (LZU) to Gwinnett County Briscoe Field (LZU)
Event
- NTSB case
- ERA18FA137
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 1 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Piper PA28R 200
- Aircraft type
- Piper PA28
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N4363F
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Gwinnett County Briscoe Field (LZU), Lawrenceville, GATo Gwinnett County Briscoe Field (LZU), Lawrenceville, GA
- Aircraft age
- About 42 years (built 1976)
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Loss of engine power (partial)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Aircraft › Aircraft power plant
- Personnel issues › Task performance
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The commercial pilot receiving instruction and a flight instructor were conducting a local instructional flight when the engine lost partial power and oil obscured the front windscreen. The instructor took control of the airplane and maneuvered toward a highway on which to conduct a forced landing; the airplane struck power lines and a vehicle before veering off the road and down a steep embankment, where it came to rest inverted.
Examination of the engine revealed that the No. 2 cylinder had separated from the cylinder mounting deck. The No. 2 cylinder rocker box cover and a pushrod tube were protruding from the left forward side of the cowling. The No. 2 cylinder connecting rod was protruding through the top of the cowling. The No. 2 cylinder base studs and thru bolts remained in the crankcase and were fractured at their threaded section. Metallurgical examination revealed that each of the fractured surfaces exhibited evidence of crack arrest marks consistent with fatigue cracking and microvoid coalescence features typical of overstress separation. The crankcase web mating surfaces at the Nos. 2, 3 and 4 bearing journals exhibited pitting consistent with fretting, which is typically a result of inadequate preload tension or loss of preload tension to the fasteners that secure the cylinder to the engine. The inadequate or loss of preload resulted in fatigue cracking of the No. 2 cylinder studs and thru-bolts, and the subsequent separation of the cylinder.
According to maintenance records, the engine underwent a major overhaul about 4 years before the accident and had accrued 1,071.11 hours since the last overhaul. At the time of the overhaul, the crankcase was reassembled, and all four cylinders were installed. It could not be determined if the thru-bolts and studs were improperly tightened by maintenance personnel at the time of the overhaul or during an undocumented maintenance action that was performed after the overhaul.
Toxicology testing of the flight instructor revealed an unquantifiable amount of doxylamine, a sedating antihistamine that was well below that considered to cause significant effects. Therefore, it is unlikely that the pilot's use of doxylamine contributed to his inability to successfully perform a forced landing on a highway.
Probable cause
A partial loss of engine power due to inadequate thru-bolt and stud preload tension by undetermined maintenance personnel, which resulted in fretting between the engine crankcase halves, and the subsequent separation of the No. 2 cylinder due to the fatigue failure of the No. 2 cylinder stud/thru bolts.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA18FA137
- Event ID
- 20180428X83650
- Case number
- ERA18FA137
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: ce11effddeda7f7494c2d2d63ba1170a0b9eeea5e1a902f021b1c3ed2191645f; retrieved 2026-09-15T06:39:49.191Z.