Tatonduk Outfitters Douglas C 118A incident
Douglas C 118A · Incident: aircraft structural failure
From Ted Stevens Anchorage International Airport (ANC) to Emmonak Airport (ENM)
Event
- NTSB case
- ENG14IA016
- 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
- Incident
- 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
- Airline
- 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
Douglas C 118A
- Aircraft type
- Douglas C-118
- 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
- N351CE
- Operator
- Tatonduk Outfitters Limited Dba
- Onboard fatalities
- Unknown
- Route
- From Ted Stevens Anchorage International Airport (ANC), Anchorage, AKTo Emmonak Airport (ENM), Emmonak, AK
- Aircraft age
- About 60 years (built 1954)
- 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 121: Air Carrier
- 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
- Unknown
- 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
- Aircraft structural failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Minor
Cause areas
- Aircraft › Aircraft structures
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The airplane suffered a crack in the left wing lower skin just inside the left inboard engine nacelle. The crack was discovered by the flight crew during a post flight inspection when they saw fuel streaming from the nacelle area. The incident airplane was manufactured in 1954 and had accrued almost 36,900 flight hours.
Examination of the lower wing skin revealed a crack with a total length about 15.5 inches. Two separate regions of pre-exiting progressive fracture were found that totaled about 4.12 inches in length. Fatigue cracking initiated and progressed from two separate rivet holes where a stringer was attached to the wing skin. There were no material discrepancies or other anomalies noted at the fatigue initiation sites. The remainder of the fracture was due to overstress separation.
The fractured area of lower wing skin was inspected by x-ray in accordance with an existing Airworthiness Directive 611.7 hours prior to the discovery of the crack. No discrepancies were reported from this inspection. Post incident examination of the x-ray films showed the crack was present but very difficult to detect without close scrutiny, optimal lighting and a known crack location.
The manufacturer released a Service Bulletin based on the findings of the investigation to provide more detailed instructions and additional methods to detect cracking of the lower wing skin at the inboard nacelle area.
Probable cause
The fatigue failure of the lower wing skin due to aging mechanisms. Contributing to the failure were lower wing skin inspection procedures insufficient to identify the crack.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ENG14IA016
- Event ID
- 20140603X95748
- Case number
- ENG14IA016
- 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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2014-02-25.
- API snapshot SHA-256: 4fe09aca03c2fcb76c5ea0aa9aae3bf34a738e22fe865741c3c5fb1cc484ef44; retrieved 2026-09-15T23:44:17.127Z.