CHI08LA166 · Helton LARK 95
Helton LARK 95 · Accident: loss of engine power (partial) during initial climb
From Moraine Air Park (I73) to Reno, NV
Event
- NTSB case
- CHI08LA166
- 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
Helton LARK 95
- Aircraft type
- Helton LARK 95
- 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
- N86657
- Operator
- Leonard E. Notek · private individual
- Onboard fatalities
- Unknown
- Route
- From Moraine Air Park (I73), Moraine, OHTo Reno, NV
- Aircraft age
- Not recorded
- 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
- Initial climb
- 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)
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Pole; Tree(s)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Aircraft › Aircraft power plant
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
Shortly after takeoff, the airplane entered a descending left turn. The airplane contacted a utility pole, a light pole, and a tree prior to coming to rest. A witness stated the airplane sounded fine on takeoff, but the engine began to lose power shortly thereafter. Post accident inspection of the airplane and engine revealed the number four cylinder sustained impact damage in the area of the top spark plug. The top spark plug on this cylinder was found separated from the engine. The top spark plugs on the remaining cylinders were loose. The accident occurred on the first flight following an annual inspection. The mechanic who signed off the inspection stated he checked the torque on the spark plugs after they were installed. The airplane was topped off with fuel prior to the flight. The pilot's logbook did not show any entries indicating that he had ever flown a Lark 95 prior to the accident flight and the passenger stated this was the pilot's first flight in the airplane.
Probable cause
The improper installation of spark plugs during the annual inspection which resulted in a loss of engine power shortly after takeoff. Contributing to the accident was the lack of suitable terrain during the forced landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI08LA166
- Event ID
- 20080623X00891
- Case number
- CHI08LA166
- 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: fd4f807804b8ca93d992f7d807bcdf07276915bfcf50fbe33cf5b2a1d99c3b20; retrieved 2026-09-13T19:08:25.131Z.