Polar Air Cargo Flight 8445
Boeing 747-123 · Incident: fire during initial climb
From Ted Stevens Anchorage International Airport (PANC) to Osan Air Base (RKSO)
Event
- NTSB case
- ANC05IA020
- 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
Boeing 747-123
- Aircraft type
- Boeing 747
- 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
- N858FT
- Operator
- Polar Air Cargo
- Onboard fatalities
- Unknown
- Route
- From Ted Stevens Anchorage International Airport (PANC), Anchorage, AKTo Osan Air Base (RKSO), Osan Air Base
- 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 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
- Initial climb
- 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
- Fire
- 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
- Fuel system, line fitting › Failure, total
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The 14 CFR Part 121 international cargo flight had an under-cowl fire in the number four engine during takeoff. The crew shut down the engine, activated the fire extinguishing system, and returned to the airport. An inspection of the engine disclosed that the entire outboard engine cowl was missing, and the engine had extensive fire damage. A fuel tube to the oil cooler was observed to have separated from the coupler attaching it to the oil cooler, leaving a gap of about one-half inch. The oil cooler uses the heat-exchange principle, exchanging heat via high quantity fuel flow. The fuel tube is about one and one-quarter inches in diameter, and has a working pressure of about 200 psi. Separation of the fuel tube assembly connection occurred at the brazed sleeve joint between the ferrule and the fuel tube. An examination and X-ray mapping revealed that the brazed joint did not meet the minimum requirement for filler material adhesion required in Aerospace Material Specification (AMS) 2664F for silver brazing.
Probable cause
The failure of a high-pressure fuel line fitting, which resulted in an engine fire during takeoff/initial climb.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC05IA020
- Event ID
- 20050106X00021
- Case number
- ANC05IA020
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (5)
- 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: 968a7a99f93fca491f97dc505a03afbda0fb432973fe2d65647e21a4986201fe; retrieved 2026-09-18T15:09:50.267Z.
- The NTSB's operator name is blank for N858FT; the operator shown is the name the NTSB records it doing business as.