# NTSB WPR14LA340: Hughes 269C, N7432F, Darrington, WA, August 11, 2014 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 11, 2014, 11:30 local (18:30 UTC) - Place: Darrington, WA - Coordinates: 48.270832, -121.208885 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=48.2708&lon=-121.2089&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-descent: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report October 23, 2017 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 89852 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR14LA340 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/89852/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=89852 - Page: https://openairdocs.org/ntsb/WPR14LA340 ## Probable cause Maintenance personnel’s failure to secure the throttle mount bracket during a recent engine installation, which resulted in the loss of throttle movement and an inability to control engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine controls: power lever](https://openairdocs.org/ntsb-findings/01057603): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause); cases with it: [Hughes 269C, 2 cases](https://openairdocs.org/ntsb-findings/01057603/cases.md?model=4470504), [All aircraft, 95 cases](https://openairdocs.org/ntsb-findings/01057603/cases.md) - [Maintenance: installation](https://openairdocs.org/ntsb-findings/02062035): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Hughes 269C, 1 case](https://openairdocs.org/ntsb-findings/02062035/cases.md?model=4470504), [All aircraft, 371 cases](https://openairdocs.org/ntsb-findings/02062035/cases.md) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Hughes 269C, 1 case](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=4470504), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md) - [Object/animal/substance: water/moisture](https://openairdocs.org/ntsb-findings/03022057): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Hughes 269C, 1 case](https://openairdocs.org/ntsb-findings/03022057/cases.md?model=4470504), [All aircraft, 10 cases](https://openairdocs.org/ntsb-findings/03022057/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-descent: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Hughes 269C, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=4470504), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Autorotation: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Hughes 269C, 4 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=4470504), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Autorotation: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Hughes 269C, 10 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=4470504), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The commercial pilot was conducting a local, personal flight in the rented helicopter. The pilot reported that, while descending the helicopter from 5,000 ft and approaching 4,000 ft, he increased the collective and noticed that the engine was slowing down; he was unable to recover the engine rpm to a normal range. The helicopter continued to descend until the pilot entered an autorotation. The helicopter then impacted a tree and came to rest in a small stream. The pilot stated that he did not believe that the engine ever quit but that it did not produce enough power to continue flight. Postaccident examination of the helicopter revealed that the throttle mount bracket was hanging by the throttle cable linkage and was not secured to the servo mount studs, which would have led to the loss of throttle movement for acceleration. The operator stated that the engine had been installed in the helicopter 10 flight hours before the accident. It is likely that maintenance personnel did not properly secure the throttle mount bracket during the engine installation, which led to the loss of throttle movement and inability to control engine power. ## Factual narrative On August 11, 2014, about 1130 Pacific daylight time (PDT), a Hughes 269C Helicopter, N7432F, impacted terrain following a partial loss of engine power near Darrington, Washington. The airline transport pilot was not injured; the helicopter sustained substantial damage. Snohomish Flying Service (SFS) was operating the helicopter under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The local personal flight departed Snohomish, Washington, about 0815. Visual meteorological conditions prevailed, and no flight plan had been filed.The pilot reported that during a flight in the rented helicopter he was descending out of 5,000 ft. As he approached 4,000 ft, he increased collective and noticed that the engine was slowing down; he was unable to recover the engine rpm to a normal range. The helicopter continued to descend until the pilot entered an autorotation. The helicopter impacted a tree about 30 ft high and then came to rest in a small stream. The pilot stated he did not believe the engine ever quit, but the engine would not produce enough power to continue flight. The helicopter was recovered on August 12, 2014, by SFS and examined by Federal Aviation Administration inspectors with assistance from SFS personnel. They found that the throttle mount bracket was hanging by the throttle cable linkage and was not secured to the servo mount studs as it should have been. This would prevent the loss of throttle movement for acceleration. The operator stated that the engine had just been installed into the helicopter 10 flight hours prior to the accident. ## Aircraft - Registration: [N7432F](https://openairdocs.org/deregistered/N7432F-2018-03-28), registration cancelled 2018-03-28, S/N 160458, built 1976 (OpenAirDocs) - Reported make and model: HUGHES 269C - Registry model: [Hughes 269C](https://openairdocs.org/model/hughes-269c) (registry code 4470504) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Helicopter - Serial number: 160458 - Year built: 1976 - Airframe hours: 3015 - Engines: Lycoming HIO-360-D1A 200 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 9, 2014 - Departed: S43, SNOHOMISH, WA - Destination: S43, SNOHOMISH, WA - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 59; injuries: none; commercial, airline transport, private; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review July 13, 2014; seat: left; restraint: 4-point; flight hours: 18,000 total, 80 in this make and model, 10,000 as pilot in command, 270 in the last 90 days, 90 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 300° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 77 °F, dew point 61 °F - Altimeter: 29.93 inHg - Observed at: AWO, 19 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20140811013229A](https://openairdocs.org/incident/20140811013229A), Aug 11, 2014: Hughes 269C, Darington, WA, Substantial damage. The nuts securing the throttle suport bracket vibrated loose causing the bracket to come off the mount studs and loss of throttle control. ## Other investigations on N7432F (2) 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. - [NTSB SEA77DYA27](https://openairdocs.org/ntsb/SEA77DYA27), Jul 5, 1977: Hughes 269C (N7432F), Gooding, ID, destroyed - [NTSB SEA76DYA39](https://openairdocs.org/ntsb/SEA76DYA39), Jul 10, 1976: Hughes 269A (N7432F), Gooding, ID, substantial damage ## Docket (2 files) The files NTSB released with the investigation on October 5, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=89852. 933 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 8 photos, 889 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40456838&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - FAA Examination Statement (item 2, .PDF, 45 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40456839&FileExtension=.PDF&FileName=FAA%20Examination%20Statement-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.