WPR23LA192 · Viking Air Limited DHC-6-400
Bank of Utah Trustee Viking Air Limited DHC-6-400 · Accident: system/component malfunction/failure (non-power) en route
From Charles M. Schulz Sonoma County Airport (STS) to Daniel K. Inouye International Airport (HNL)
Event
- NTSB case
- WPR23LA192
- 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
Viking Air Limited DHC-6-400
- Aircraft type
- Viking Air DHC-6
- 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
- N153QS
- Operator
- Bank of Utah Trustee
- Onboard fatalities
- Unknown
- Route
- From Charles M. Schulz Sonoma County Airport (STS), Santa Rosa, CATo Daniel K. Inouye International Airport (HNL), Honolulu, HI
- Aircraft age
- About 10 years (built 2013)
- 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
- 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
- System/component malfunction/failure (non-power)
- 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
- Aircraft › Aircraft systems
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 was conducting a trans-Pacific flight when the accident occurred. A ferry fuel tank system was installed on the airplane and 1,189 gallons of fuel was added for the flight. About 4 hours into the flight over the Pacific Ocean, the crew contacted air traffic control (ATC) and reported that they were having a fuel transfer problem and were thinking of turning around. The crew then reported they were declaring an emergency and had 10 hours of fuel remaining but could only access about 2 hours of fuel. Satellite flight track data showed the airplane reversed course when it was about 356 miles from the California coast. About 132 miles from the coast the flight track decreases in altitude to about 4,000 ft above mean sea level (msl). The last few minutes of the data shows the altitude decrease from about 3,600 ft msl to about 240 ft msl. The last track data point was located about 33 miles off the California coast. The United States Coast Guard (USCG) responded to the accident location and reported the fuselage was inverted in the water. They reported the wings and engines were separated from the fuselage. The pilots were still strapped in their seats and unresponsive. The occupants were not recovered. Search efforts resulted in finding the nose landing gear, right wing, and right engine. A fuel bladder tank had washed ashore in southern California. Postaccident examination of the recovered components revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. A mechanic reported that he was instructed to set up the ferry fuel tank system in the accident airplane. He installed but did not fill the system with fuel, as he did not know when the flight would take place and it would have been unsafe to have the bladders contain fuel for several days before the flight. After installing the ferry fuel tank system, he contacted the copilot (who was also a mechanic), who was then to complete the installation. The mechanic understood that the copilot would be responsible for the final installation of the ferry fuel tank system and complete the appropriate logbook entries. The mechanic was not present when the copilot completed the installation and was not sure if the copilot had signed off on it.
Probable cause
The failure of the ferry fuel tank system to transfer fuel during a trans-Pacific flight for reasons that could not be determined, which resulted in fuel starvation and a subsequent ditching into the water.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR23LA192
- Event ID
- 20230520184404
- Case number
- WPR23LA192
- 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: investigation status, coordinates, cause areas. 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: d0fdaa442d5f915a49714d612228d3e1b4cbf90a357c07367275f376138aa6ea; retrieved 2026-09-15T08:00:09.203Z.