ANC96LA053 · Maule M-5-210C
Maule M-5-210C · Accident: total loss of engine power (mechanical failure) en route
From Grayling Airport (KGX) to Edward G. Pitka Sr Airport (GAL)
Event
- NTSB case
- ANC96LA053
- 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
Maule M-5-210C
- Aircraft type
- Maule M-5
- 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
- N9704N
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Grayling Airport (KGX), AKTo Edward G. Pitka Sr Airport (GAL), GALENA, AK
- 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
- Destroyed
Cause areas
- Accessory drive assembly, drive gear › Jammed
- Electrical system, alternator › Sheared
- Engine assembly, connecting rod › Failure
- Fluid, oil › Starvation
- Lubricating system, oil pressure pump › Sheared
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The certificated private pilot departed a remote airstrip. About 1,000 feet above the ground, the engine quit. The pilot performed an emergency landing on soft snow covered terrain and the airplane nosed over. An engine examination revealed that the alternator drive coupling, consisting of a hub, retainer and bushing, fragmented within the engine. The alternator drive shaft and the oil pump gear were fractured when fragments of the retainer were enmeshed in the engine accessory gear teeth that drove both accessories. The number 6 cylinder connecting rod failed and penetrated the engine case due to a lack of lubrication. The engine, including the alternator, was overhauled 250 hours before the accident. An engine manufacturer's service bulletin recommended inspection and replacement of the standard alternator drive coupling every 500 hours. The engine manufacturer offered a one piece alternator drive coupling in which the retainer, bushing and hub were bonded together as one unit.
Probable cause
disintegration of the alternator drive coupling, jamming of the accessory drive gear, shearing of the oil pump drive, oil starvation, and failure of the number 6 cylinder connecting rod. Non-compliance with a manufacturer's service bulletin and soft snow were factors in the accident.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC96LA053
- Event ID
- 20001208X05501
- Case number
- ANC96LA053
- 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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 1996-04-21.
- API snapshot SHA-256: 44fb982992ab0d5082a87ef4101099f99a6734987851bce383f7a3647793abb1; retrieved 2026-09-22T22:36:35.843Z.