ATL05LA052 · WSK PZL Mielec M-18A
WSK PZL Mielec M-18A · Accident: total loss of engine power (mechanical failure) en route
From 50J · Moncks Corner, SC to 50J · Moncks Corner, SC
Event
- NTSB case
- ATL05LA052
- 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
- 0
- 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
WSK PZL Mielec M-18A
- Aircraft type
- WSK PZL Mielec M-18
- 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
- N2296Y
- Operator
- David Melvin Hill
- Onboard fatalities
- Unknown
- Route
- From 50J · Moncks Corner, SCTo 50J · Moncks Corner, SC
- 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 137: Agricultural
- 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)
- 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
- 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
- Substantial
Cause areas
- Propeller system/accessories, planetary gear › Fractured
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
While approaching Moncks Corner Airport to land, the airplane's engine seized and the pilot was forced to land on tree tops about 400 feet from the runway. Post-accident examination of the engine assembly revealed four fatigue cracks on the planetary carrier housing that propagated outboard and caused the housing to fracture into multiple pieces. The teeth around the sun gear in the area that corresponds to the planetary gears were fractured and exhibited deformation. The teeth of the planetary gears showed deformation. The splined lock was examined and exhibited fretting damage. The width of the fretting/galling damage on the four flat surfaces was wider compared to the thickness of the mating square slot on the cap, consistent with lateral movement between the splined lock and cap. All spine teeth on the splined lock showed deformation. Dimensional inspection of the gears were performed on the engine approximately 98 hours prior to the accident. At that time, a new sun gear was installed in the engine. The mating four planetary gears were not replaced and not required to be replaced. Uneven wear between gear faces caused stresses to be distributed unevenly between the gears, resulting in accelerated wear of the gears. Wear of the planetary gears are required to be evaluated when the engine is overhauled, but there is no record of a recent engine overhaul.
Probable cause
The fatigue cracking of the planetary gear housing, which resulted in the loss of engine power.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ATL05LA052
- Event ID
- 20050224X00227
- Case number
- ATL05LA052
- 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: b488d8102561d86dcef2ce13172e28874e595246ef5c99f57c097ea44ab9ac5e; retrieved 2026-09-22T06:15:27.759Z.