# Accessory drives - Type: NTSB finding subsection - Path: [Aircraft](https://openairdocs.org/ntsb-findings/01) › [Aircraft power plant](https://openairdocs.org/ntsb-findings/0105) › [Engine (turbine/turboprop)](https://openairdocs.org/ntsb-findings/010572) › Accessory drives - NTSB code: 01057260 - Cases: 12 - In the probable cause: 12 - Fatal cases: 2 - All cases: https://openairdocs.org/ntsb-findings/01057260/cases.md - Cases with it in the probable cause: https://openairdocs.org/ntsb-findings/01057260/cases.md?cause=1 - Page: https://openairdocs.org/ntsb-findings/01057260 ## Cases per year (in the probable cause / all) - 2011: 3 / 3 - 2013: 2 / 2 - 2014: 1 / 1 - 2017: 2 / 2 - 2019: 1 / 1 - 2021: 1 / 1 - 2022: 1 / 1 - 2023: 1 / 1 ## Defining events in these cases - [Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340): 6 cases - [Loss of engine power (total)](https://openairdocs.org/ntsb-events/341): 3 cases - [Uncontained engine failure](https://openairdocs.org/ntsb-events/343): 1 cases - [Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342): 1 cases - [Fire/smoke (non-impact)](https://openairdocs.org/ntsb-events/150): 1 cases ## Aircraft models (registry) - [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e): 1 cases - [Douglas DC-9-83](https://openairdocs.org/model/douglas-dc-9-83): 1 cases - [Arrow Falcon Exporters UH-1H](https://openairdocs.org/model/arrow-falcon-exporters-uh-1h): 1 cases - [Boeing 757-232](https://openairdocs.org/model/boeing-757-232): 1 cases - [Boeing 737-7H4](https://openairdocs.org/model/boeing-737-7h4): 1 cases - [Ag-Cat G-164B](https://openairdocs.org/model/ag-cat-g-164b): 1 cases - [Bell 407](https://openairdocs.org/model/bell-407): 1 cases - [Bell Helicopter Textron 206L-1](https://openairdocs.org/model/bell-helicopter-textron-206l-1): 1 cases - [Bell UH-1H](https://openairdocs.org/model/bell-uh-1h): 1 cases - [Ayres S2R-G6](https://openairdocs.org/model/ayres-s2r-g6): 1 cases ## Other findings in the same cases - [Not determined, general](https://openairdocs.org/ntsb-findings/05000000) (Not determined): 1 cases - [Design of document/info](https://openairdocs.org/ntsb-findings/04011020) (Organizational issues): 1 cases - [Light condition, general](https://openairdocs.org/ntsb-findings/03036000) (Environmental issues): 1 cases - [High density altitude](https://openairdocs.org/ntsb-findings/03031020) (Environmental issues): 1 cases - [Maintenance, general](https://openairdocs.org/ntsb-findings/02062000) (Personnel issues): 1 cases - [Scheduled/routine inspection](https://openairdocs.org/ntsb-findings/02061520) (Personnel issues): 1 cases - [Oil](https://openairdocs.org/ntsb-findings/01071020) (Aircraft): 1 cases ## Newest cases - [NTSB ERA23LA272](https://openairdocs.org/ntsb/ERA23LA272), Jun 20, 2023: Air Tractor AT802 (N3069S), Wellington, FL, substantial damage. Probable cause: Wear of the fuel control unit drive shaft and the corresponding fuel pump drive gear, which resulted in the disengagement of the fuel control unit from the fuel pump, a decrease in fuel flow, and a… - [NTSB CEN22FA317](https://openairdocs.org/ntsb/CEN22FA317), Jul 17, 2022: Bell UH-1H (N911SZ), Chapelle, NM, destroyed, 4 fatal. Probable cause: The total loss of engine power due to the fatigue failure of the starter-generator input (zerol) gear which failed due to poor maintenance. Contributing to the accident was the unsuccessful… - [NTSB CEN21LA287](https://openairdocs.org/ntsb/CEN21LA287), Jun 20, 2021: Grumman G164 (N62375), Sedgwick, AR, substantial damage. Probable cause: The total loss of engine power due to the failure and disengagement of the torque sensor assembly front spur gear from its splined shouldered shaft due to a loose self-locking nut. - [NTSB CEN20FA035](https://openairdocs.org/ntsb/CEN20FA035), Dec 7, 2019: Bell 407 (N79LP), Gulf of Mexico (Gulf of Mexico), destroyed, 2 fatal. Probable cause: A total loss of engine power due to the failure of the engine’s Nos. 3 and 4 bearings and the power turbine pinion gear, and subsequent loss of main rotor rpm, which resulted in a loss of control and… - [NTSB ENG17IA027](https://openairdocs.org/ntsb/ENG17IA027), Jun 3, 2017: Boeing 737 7H4 (N765SW), Washington, DC, incident, minor damage. Probable cause: The failure the control alternator gearshaft, which disconnected the accessory gearbox from the rest of the engine and resulted in an uncommanded in-flight shutdown of the left engine and subsequent… - [NTSB ENG17IA017](https://openairdocs.org/ntsb/ENG17IA017), Mar 19, 2017: Douglas DC 9 83 (N881GA), Dayton, OH, incident, no damage. Probable cause: The probable cause of the No. 2 (right) engine fire was an uncontained generator failure. Deformed rotating generator components and/or metal fragments radially released by the generator severed the… - [NTSB ERA14LA361](https://openairdocs.org/ntsb/ERA14LA361), Jul 26, 2014: Hiller UH 12E (N107HA), Wadesboro, NC, substantial damage. Probable cause: A partial loss of engine power due to the failure of the No. 2 engine accessory gearbox bearing for reasons that could not be determined based on the available information. - [NTSB WPR14LA014](https://openairdocs.org/ntsb/WPR14LA014), Oct 11, 2013: Bell Helicopter Textron 206L 1 (N206KK), Seeley, CA, destroyed. Probable cause: The total loss of engine power due to the failure of the No. 4 bearing. - [NTSB ENG13IA033](https://openairdocs.org/ntsb/ENG13IA033), Jul 2, 2013: Boeing 777 (HL8275), Ugolny Airport, Russia, incident, no damage. Probable cause: The failure of the transfer gearbox resulting from the fracture and separation of the radial gearshaft from fatigue cracking as a result of a combination of high residual tensile stresses produced by… - [NTSB WPR11LA423](https://openairdocs.org/ntsb/WPR11LA423), Sep 2, 2011: Arrow Falcon Exporters UH-1H (N205PJ), Stockton, CA, substantial damage. Probable cause: A total loss of engine power due to the separation of a tooth from the starter-generator drive gear, which resulted in failure of the engine oil pump and subsequent oil starvation. NTSB has coded findings and defining events since 2008; earlier cases used its older occurrence and cause codes and aren't counted. Findings: https://openairdocs.org/ntsb-findings.md. Defining events: https://openairdocs.org/ntsb-events.md. Phases of flight: https://openairdocs.org/ntsb-phases.md. Every investigation, filtered by finding, event, phase, state, year or model: https://openairdocs.org/ntsb.md (for example ?state=MI&fatal=1). NTSB's definitions: Accident and incident, 49 CFR 830.2 (https://www.ecfr.gov/current/title-49/subtitle-B/chapter-VIII/part-830/subpart-A/section-830.2), CICTT occurrence categories (PDF) (https://www.ntsb.gov/safety/data/Documents/datafiles/OccurrenceCategoryDefinitions.pdf), CICTT phases of flight (PDF) (https://www.ntsb.gov/safety/data/Documents/datafiles/PhaseofFlightDefinitions.pdf), and NTSB coding manual, before 2008 (PDF) (https://www.ntsb.gov/GILS/Documents/codman.pdf). NTSB publishes no definitions for its findings, only their names. --- 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.