CEN19FA109 · Aerospatiale AS350 B3
Mountain Air Helicopters Aerospatiale AS350 B3 · Accident: loss of engine power (total) while maneuvering
Event
- NTSB case
- CEN19FA109
- 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
- 1 · 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
- Government
- 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
Aerospatiale AS350 B3
- Aircraft type
- Aerospatiale AS350
- 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
- N818MC
- Operator
- Mountain Air Helicopters
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- Aircraft age
- About 10 years (built 2009)
- 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
- Public Aircraft
- 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
- Maneuvering · low-altitude flying
- 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
- Loss of engine power (total)
- 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
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
While conducting controlled fire operations, the helicopter was maneuvering over trees, when the engine lost power. The pilot performed an autorotation and the helicopter impacted trees and then terrain, and came to rest on its side. The fuselage and empennage sustained substantial damage. One crewmember was fatally injured.
Examination revealed that a fuel line between the engine firewall and hydro-mechanical unit (HMU) was loose and not secured with safety wire as required. About 25 flight hours before the accident, that fuel line was disconnected to defuel of the helicopter in order to perform a weight and balance check. No other maintenance was performed in that area. The mechanic who returned the helicopter to service stated that he was confident that he torqued and secured the line. No other anomalies were detected with the helicopter which would have precluded normal flight.
The circumstances of the accident are consistent with a loss of engine power due to the loose fuel line.
Probable cause
Maintenance personnel's failure to properly re-install and secure a fuel line, which resulted in a total loss of engine power.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN19FA109
- Event ID
- 20190327X81509
- Case number
- CEN19FA109
- 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, 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: 75ed30dc04ab23c4972ffb21d5ff54da51922ab4c4b11555be5ea603e2c912b2; retrieved 2026-09-15T06:56:05.987Z.