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WPR17LA014 · Aerospatiale AS350 BA

28 Oct 2016 · Starbuck, WA, United States

Leading Edge Aviation Aerospatiale AS350 BA · Accident: loss of engine power (total) while maneuvering

From Starbuck, WA to Starbuck, WA

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Event

NTSB case
WPR17LA014
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
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

Aerospatiale AS350 BA

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
N369BD
Onboard fatalities
Unknown
Route
From Starbuck, WATo Starbuck, WA
Aircraft age
About 33 years (built 1983)
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
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
  • Aircraft › Fluids/miscellaneous hardware

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

The commercial pilot reported that, during the agricultural application flight in the helicopter, the fuel pressure warning light illuminated. The pilot scanned the instruments and noted that the fuel pressure was low and that the fuel quantity was indicating between 40% and 50%. Subsequently, the engine started to lose power. The pilot entered an autorotation and set up the helicopter for landing in the flattest area. Subsequently, the helicopter landed hard, which resulted in substantial damage to the tailboom and main rotor assembly.

Postaccident examination of the helicopter revealed that the fuel tank was intact, undamaged, and empty of fuel. Given this evidence, the engine likely lost all power due to fuel exhaustion.

Despite the lack of fuel, the fuel quantity gauge indicated that 42% of the fuel was remaining (or about 60 gallons). Disassembly of the fuel transmitter revealed that the float guide pin was separated from the float assembly at the tack weld. The separation of the float guide pin allowed the float to slide down the center torque shaft and prevented the potentiometer drive plate at the bottom from rotating when the fuel quantity changed, which led to the fuel quantity gauge displaying an incorrect fuel level.

A review of the airplane's maintenance records revealed that the fuel transmitter was overhauled about 11 months before the accident. Given the evidence, it is likely that, during the overhaul, maintenance personnel improperly welded the float pin guide to its mount and subsequently did not adequately inspect it, which led to its eventual separation from the assembly at the welded area.

Probable cause

A total loss of engine power due to fuel exhaustion, which resulted from the pilot’s reliance on the fuel gauge that was displaying an incorrect fuel amount due to the separation of the fuel transmitter float pin guide from the float.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record WPR17LA014
Event ID
20161031X33238
Case number
WPR17LA014
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. 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: 75e7a3c79f78afca09b220a34f73240da556469050400cd86495818b93106a33; retrieved 2026-09-16T04:47:51.293Z.