FTW89FA075 · Bell 206B
Industrial Helicopters Bell 206B · Accident: partial loss of engine power (non-mechanical) on approach
Event
- NTSB case
- FTW89FA075
- 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
Bell 206B
- Aircraft type
- Bell 206
- Category
- Helicopter
- 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
- N5004L
- Operator
- Industrial Helicopters
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- 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
- Approach · VFR pattern final
- 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
- Partial loss of engine power (non-mechanical)
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Fuel contamination
- 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
- Company maintenance personnel › Maintenance, inspection, inadequate
- Fluid, fuel › Contamination
Not plotted · Location withheld: coordinates are missing, conflicting, invalid, or have no accepted acquisition method. No substitute location has been invented.
NTSB narrative
THE HELICOPTER HAD SVRL INFLT ENG DECELERATIONS THAT MAINTENANCE EFFORTS DID NOT ISOLATE. AFTER REPLACING THE ENG FUEL CONTROLLER, A TEST FLT WAS MADE (FROM AN OIL DRILLING PLATFORM). DRG THE FLT, THE ENG SURGED, THEN DECELERATED. THE PLT WAS UNABLE TO REACH THE HELIPAD. HE ELECTED TO LAND ON THE PLATFORM, SHORT OF THE HELIPAD, RATHER THAN ACCEPT SEA CONDS OF 8 FT WAVES. DRG THE LANDING, THE HELICOPTER WAS DAMAGED. A POST-ACDNT EXAM REVEALED FUEL CONTAMINATION HAD OCCURRED. CONTAMINATION HAD BYPASSED FILTERS IN THE FUEL SYS & HAD CLOGGED & COLLAPSED THE ENG FUEL NOZZLE SCREEN. THE AIRFRAME FUEL FILTER CAP BYPASS VLV WAS FND STUCK OPEN IN THE BYPASS MODE. A PIN (CONNECTED TO THE FUEL FILTER CAP IMPENDING BYPASS TEST BUTTON) WAS FND BENT, HOLDING THE BYPASS VLV OPEN. AN OPEN BYPASS VLV SHOULD HAVE ILLUMINATED A RESPECTIVE ANNUNCIATOR LIGHT IN THE COCKPIT; HOWEVER, WHEN CHECKED, THE ANNUNCIATOR LIGHT OPERD ONLY INTERMITTENTLY DUE TO A FAULTYCOMPONENT IN THE SYS. DRG TESTS, THE CLOGGED/COLLAPSED FUEL SCREEN PREVENTED SUFFICIENT FUEL FLOW TO SUSTAIN ENG POWER.
Probable cause
INADEQUATE MAINTENANCE/INSPECTION OF THE AIRCRAFT FUEL SYSTEM BY COMPANY MAINTENANCE PERSONNEL AND FUEL CONTAMINATION, WHICH RESULTED IN A PARTIAL LOSS OF ENGINE POWER. RELATED FACTORS WERE: A BINDING (STUCK) FUEL FILTER CAP BYPASS VALVE AND PARTIAL FAILURE (INTERMITTENT OPERATION) OF THE RESPECTIVE ANNUNCIATOR LIGHT SYSTEM.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW89FA075
- Event ID
- 20001213X28089
- Case number
- FTW89FA075
- 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: fc474ed917edf2515cb5c961bef67ad0f05f4bda8286bce3c322ffb7d7be8c93; retrieved 2026-09-23T07:44:19.541Z.