ANC04FA092 · Maule M-5-235C
Maule M-5-235C · Accident: airframe, component or system failure en route
From Birchwood Airport (BCV) to Seward Airport (SWD)
Narrative check · The NTSB narrative appears to contradict this record's location and departure or destination. Values are shown as recorded, not corrected; compare with the narrative.
Event
- NTSB case
- ANC04FA092
- 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
- 2 · 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
Maule M-5-235C
- 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
- N6194M
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route Possible conflict
- From Birchwood Airport (BCV), Chugiak, AKTo Seward Airport (SWD), Seward, 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
- Airframe, component or system 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
- Fluid, oil › Loss, total
- Other maintenance personnel › Maintenance, inspection, inadequate
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The private pilot, with two passengers, was flying one of two wheel-equipped airplanes en route to a remote beach site. The route of flight was over ocean waters, flanked by steep vertical cliffs to the waters edge. After passing over the last suitable landing site, an airport about 12 miles north, the accident pilot reported to the pilot of the second airplane that he had a severe engine oil leak, and was retuning to the airport. The pilot reported that once the oil stopped leaking, about 3 miles from the airport, the engine began to vibrate so violently that he thought the engine was going to be torn from its mounts, and he shut the engine off. He said he turned the airplane in an attempt to glide to the nearest beach, but he was unable to reach the beach, and was forced to ditch the airplane about 300 yards from shore. When the airplane's main landing gear wheels touched the water, it nosed over abruptly, and the cabin rapidly filled with water. The pilot said he struggled to free himself and the passengers from their seat belts, while upside-down, and submerged in cold ocean water. Once he was free, he swam to the rear of the airplane, kicked out one of the aft windows, swam to the surface, and summoned help. Rescue personnel discovered the two passengers still restrained within their seats. A postaccident examination of the engine revealed that a hex head plug at the front of the engine, in front of the propeller governor idler gear shaft, was missing, allowing engine oil under pressure to flow overboard. Additionally, the propeller governor idler gear shaft setscrew was loose, and the idler gear shaft was missing. There was no evidence that the hex head plug had been safety wired as required at the last engine overhaul, 299.6 service hours prior to the accident. According to the owner/pilot, he and a friend assembled the overhauled components of the accident engine in the pilot/owner's home-based shop. He said that that all work was accomplished in accordance with Textron Lycoming technical data. The pilot/owner did not possess an aviation mechanic's certificate. The pilot/owner reported that his friend, who owned and operated an aircraft maintenance facility, was supervising his work during the engine overhaul. A review of the engine logbooks revealed that the overhaul was certified by the pilot/owners friend, who also possessed inspector authority (IA).
Probable cause
The failure of an aviation mechanic/inspector to adequately inspect the pilot/owner's work during the engine overhaul, which resulted in a loss of engine oil and engine power during cruise flight, and a subsequent ditching. Factors associated with the accident were the inadequate installation of the idler gear shaft setscrew, and the lack of a safety wire on the three-quarter inch hex head (oil) plug in front of the idler gear shaft. Additional factors associated with the accident were the lack of suitable terrain for a forced landing, and ocean water.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC04FA092
- Event ID
- 20040824X01279
- Case number
- ANC04FA092
- 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. 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: 756ed8c0b583917695be5ccbcaa5ffce1e103a91dd785e9bca15bc0dfd79d14b; retrieved 2026-09-20T18:22:36.055Z.