CHI04LA283 · Cessna 172M
Cessna 172M · Accident: total loss of engine power (mechanical failure) en route
From Lee's Summit Municipal Airport (LXT) to Columbia Regional Airport (COU)
Event
- NTSB case
- CHI04LA283
- 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
- 0 · 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
Cessna 172M
- Aircraft type
- Cessna 172
- 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
- N80237
- Operator
- Kenneth T. Conlee · private individual
- Onboard fatalities
- Unknown
- Route
- From Lee's Summit Municipal Airport (LXT), Lee's Summit, MOTo Columbia Regional Airport (COU), Columbia, MO
- 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
- En route · cruise
- First occurrenceThe 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
- Total loss of engine power (mechanical failure)
- 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
- Engine assembly, connecting rod › Failure
- Engine assembly, connecting rod › Fatigue
- Pilot in command › Aircraft control, not maintained
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The airplane sustained impact and fire damage when it cart-wheeled during a forced landing following a loss of engine power. The pilot reported that 30 minutes into the flight he heard a "clunk", the engine stopped running, and the propeller was not windmilling. He stated he attempted to restart the engine to no avail. The pilot was attempting an off airport landing in a bean field when the right wing contacted the ground, the airplane cart wheeled, and a post impact fire ensued. Inspection of the engine revealed the piston and piston pin on the number 4 cylinder were separated from the connecting rod. The metallurgical examination of the number 4 connecting rod noted the piston pin end of the rod was fractured and the fractured ends were deformed inward. The fractured surface revealed an area typical of a fatigue crack that started at the forging parting plane on the exterior surface. The fatigue origin areas contained ratchet marks indicating that fatigue cracking initiated at multiple sites and the crack extended through approximately 60% of the wall thickness. The engine, a Lycoming O-320-E2D, was overhauled on August 11, 2003, at an engine total time of 3,918.7 hours. The engine had accumulated approximately 70 hours since the overhaul. Maintenance records indicate the connecting rods were magnafluxed, rebushed, checked for alignment, and reinstalled in the engine during the overhaul. The connecting rods were the original engine rods.
Probable cause
The fatigue failure of the piston end of the connecting rod and the pilot's failure to maintain aircraft control during the forced landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI04LA283
- Event ID
- 20040929X01527
- Case number
- CHI04LA283
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
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: c2818582b5da91e631f868f570f3aabfab4296c0eecb7bd6c29547b426b58db8; retrieved 2026-09-21T19:08:18.964Z.