# NTSB WPR17LA014: Aerospatiale AS350, N369BD, Starbuck, WA, October 28, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 28, 2016, 12:40 local (19:40 UTC) - Place: Starbuck, WA - Coordinates: 46.588333, -118.123054 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.5883&lon=-118.1231&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 13, 2020 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 94317 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR17LA014 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94317/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94317 - Page: https://openairdocs.org/ntsb/WPR17LA014 ## 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. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fuel system: fuel quantity sensor](https://openairdocs.org/ntsb-findings/01022842): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [S N I A S AS-350B ECUREUIL, 1 case](https://openairdocs.org/ntsb-findings/01022842/cases.md?model=8680801), [All aircraft, 10 cases](https://openairdocs.org/ntsb-findings/01022842/cases.md) - [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid level (probable cause); cases with it: [S N I A S AS-350B ECUREUIL, 1 case](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=8680801), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md) - [Maintenance: repair](https://openairdocs.org/ntsb-findings/02062015): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [S N I A S AS-350B ECUREUIL, 1 case](https://openairdocs.org/ntsb-findings/02062015/cases.md?model=8680801), [All aircraft, 99 cases](https://openairdocs.org/ntsb-findings/02062015/cases.md) - [Fuel system: fuel quantity sensor](https://openairdocs.org/ntsb-findings/01022842): Aircraft › Aircraft systems · Incorrect service/maintenance (probable cause); cases with it: [S N I A S AS-350B ECUREUIL, 1 case](https://openairdocs.org/ntsb-findings/01022842/cases.md?model=8680801), [All aircraft, 10 cases](https://openairdocs.org/ntsb-findings/01022842/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Miscellaneous/other](https://openairdocs.org/ntsb-events/900); cases with it: [S N I A S AS-350B ECUREUIL, 1 case](https://openairdocs.org/ntsb-events/900/sequence.md?model=8680801), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) - [Maneuvering-low-alt flying: Fuel exhaustion](https://openairdocs.org/ntsb-events/192); cases with it: [S N I A S AS-350B ECUREUIL, 1 case](https://openairdocs.org/ntsb-events/192/sequence.md?model=8680801), [All aircraft, 804 cases](https://openairdocs.org/ntsb-events/192/sequence.md) - [Maneuvering-low-alt flying: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [S N I A S AS-350B ECUREUIL, 2 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=8680801), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [S N I A S AS-350B ECUREUIL, 2 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=8680801), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [S N I A S AS-350B ECUREUIL, 2 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=8680801), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis 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. ## Factual narrative On October 28, 2016, about 1240 Pacific daylight time (PDT), a Eurocopter S.N.I.A.S. AS350B helicopter, N369BD, sustained substantial damage during a forced landing following a loss of engine power near Starbuck, Washington. The commercial pilot was not injured. The helicopter was registered to a private individual and operated by Leading Edge Aviation LLC under the provisions of Title 14 Code of Federal Regulations Part 137 as an aerial application flight. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight. The flight originated from a nearby staging area at 1137. The pilot reported that during the flight as he was making his 6th pass, on the 5th application load, and traveling upslope from the west to the east, the fuel pressure warning light illuminated. The pilot scanned the instruments and noticed the fuel pressure was low, and the fuel quantity was indicating between 40-50%. About 3-4 seconds later the engine started to lose power. The pilot entered an autorotation and set up for a landing in the flattest area he could find in the canyon. During the approach the pilot extended the landing to make it to a more suitable site. The helicopter subsequently landed hard. The helicopter sustained substantial damage to the tailboom and to the main rotor assembly. During the recovery it was noted that the helicopter fuel tank was intact, undamaged and void of fuel, but the fuel quantity gauge still indicated 42% fuel remaining, which converts to about 60-gallons.The helicopter was recovered from the accident site for further examination. Examination of the fuel transmitter revealed that the float guide pin was separated from the float assembly at the tack weld. According to the manufacturer, the separation of the float guide pin would allow the float to slide down the center torque shaft and not allow the potentiometer drive plate at the bottom to rotate with changing fuel quantity. Maintenance records for the overhauled fuel transmitter stated that the float guide was replaced at the time of overhaul on November 23, 2015. ## Aircraft - Registration: [N369BD](https://openairdocs.org/deregistered/N369BD-2018-10-23), registration cancelled 2018-10-23, S/N 1675, built 1983 (OpenAirDocs) - Reported make and model: AEROSPATIALE AS350 (BA) - Registry model: [S N I A S AS-350B ECUREUIL](https://openairdocs.org/model/s-n-i-a-s-as-350b-ecureuil) (registry code 8680801) (OpenAirDocs) - Registry engine: [Honeywell LTS101-700D-2](https://openairdocs.org/engine/honeywell-lts101-700d-2) (registry code 33825, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 1675 - Year built: 1983 - Airframe hours: 14004.8 - Engines: Honeywell LTS101700D2 732 horsepower turbo shaft - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Leading Edge Aviation LLC - Registered owner: Jim D. Pope - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, October 27, 2016, 1.6 hours before - Departed: Starbuck, WA - Destination: Starbuck, WA - Airport: 16W, Little Goose Lock And Dam ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 36; injuries: none; commercial, flight instructor; airplane ratings: single-engine land; medical: class 2, without waivers/limitations; seat: right; restraint: 4-point; flight hours: 4,529 total, 862 in this make and model, 4,441 as pilot in command, 320 in the last 90 days, 128 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 330° at 6 knots - Lowest ceiling: none - Temperature: 61 °F, dew point 45 °F - Altimeter: 29.98 inHg - Observed at: KALW, 30 nm away ## Docket (3 files) The files NTSB released with the investigation on January 15, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94317. 828 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 674 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40479923&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Pilot Statement (item 2, .PDF, 55 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40479924&FileExtension=.PDF&FileName=Pilot%20Statement-Master.PDF - Fuel Transmitter Examination Email (item 3, .PDF, 99 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40479925&FileExtension=.PDF&FileName=Fuel%20Transmitter%20Examination%20Email-Master.PDF From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.