LAX98LA134 · Bell OH-58A
Bell OH-58A · Accident: total loss of engine power (mechanical failure) during initial climb
Event
- NTSB case
- LAX98LA134
- 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 OH-58A
- Aircraft type
- Bell OH-58
- 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
- N176SJ
- Operator
- Unknown
- 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 137: Agricultural
- 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
- Total loss of engine power (mechanical 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
- Fuel system, pump › Leak
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
During the initial climb, the pilot noted that the fuel boost pump warning light had flickered on and then off, with a corresponding surge in the engine. Approximately 20 feet agl, engine power was lost and the helicopter impacted the ground. A functional field check of the fuel system was conducted and it was noted that there was a leak in the breakaway valve, which would have allowed air to enter the system. Further examination of the fuel boost pump and breakaway valve revealed that the O-rings were deteriorated. The field inspection further revealed that the inlet shutoff valve arm on the fuel boost pump was bent. According to the manufacturer's overhaul manual, if the inlet shutoff valve arm is bent it may prevent the valve from opening and restrict the fuel flow. According to the component overhaul manuals, the O-ring seals in both the fuel boost pump and the fuel breakaway valve are not required to be inspected during routine inspections and are replaced as on-condition items. A hydro leakage test and performance flow test check was conducted on the fuel boost pump with the original O-rings. The fuel boost pump did not pass the manufacturer's tests. The O-ring seals were replaced with new ones, and the fuel boost pump functioned within manufacturer's limits. The fuel control unit and fuel pump were tested and no discrepancies were found. The fuel nozzle was also tested and flowed within manufacturer's limits. Maintenance records disclosed that the last time the fuel boost pump was worked on was 5 years prior to the accident.
Probable cause
A loss of engine power due to deteriorated O-ring seals in the fuel boost pump, which allowed air to enter the fuel lines. Factors in the accident were the inadequate manufacturer's inspection criteria for the fuel boost pump O-ring seals and the resulting failure of the operator's maintenance personnel failure to detect the condition.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX98LA134
- Event ID
- 20001211X09887
- Case number
- LAX98LA134
- 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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 1998-04-09.
- API snapshot SHA-256: 6258b8f07568d6bd8de593f53d81dfe8ecfb1958d39b9f22554cb91db07bb957; retrieved 2026-09-21T20:52:17.692Z.