# NTSB DCA22MA193: Dehavilland DHC-3, N725TH, Freeland, WA, September 4, 2022

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Class 1 · Major · Final report
- Date: September 4, 2022, 15:09 local (22:09 UTC)
- Place: Freeland, WA · last ADSB from Soper 1508:51.5 crashed in Mutiny Bay, 1.3 nm from shore of Whidbey Island . Nearest zip code is Freeland, WA
- Coordinates: 47.99032, -122.58502
- Nearby events: https://openairdocs.org/map.md?lat=47.9903&lon=-122.5850&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Defining event: [Enroute: Loss of control in flight](https://openairdocs.org/ntsb-events/240)
- Highest injury: Fatal
- Injuries: 10 fatal
- Status: Completed, report September 29, 2023
- Report: Board-adopted by Notation
- Investigation class: Class 1
- NTSB office: Major Investigations Division
- Parties: Friday Harbor Seaplanes, Viking Air Limited, FAA/AVP, TSB Canada, Northwest Seaplanes
- Safety recommendations: Yes
- NTSB case key (mKey): 105855
- NTSB case page: https://www.ntsb.gov/investigations/Pages/DCA22MA193.aspx
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105855/pdf
- Board report AIR2301 (PDF): https://www.ntsb.gov/investigations/AccidentReports/Reports/AIR2301.pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=105855
- Page: https://openairdocs.org/ntsb/DCA22MA193

## Probable cause

The in-flight unthreading of the clamp nut from the horizontal stabilizer trim actuator barrel due to a missing lock ring, which resulted in the horizontal stabilizer moving to an extreme trailing-edge-down position rendering the airplane’s pitch uncontrollable.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Flight control system: stabilizer control system](https://openairdocs.org/ntsb-findings/01022740): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Dehavilland DHC-3, 1 case](https://openairdocs.org/ntsb-findings/01022740/cases.md?model=2802412), [All aircraft, 13 cases](https://openairdocs.org/ntsb-findings/01022740/cases.md)
- [Knowledge: knowledge of equipment](https://openairdocs.org/ntsb-findings/02032015): Personnel issues › Experience/knowledge · Maintenance personnel; cases with it: [Dehavilland DHC-3, 1 case](https://openairdocs.org/ntsb-findings/02032015/cases.md?model=2802412), [All aircraft, 69 cases](https://openairdocs.org/ntsb-findings/02032015/cases.md)
- [Manufacture/production: document/info production](https://openairdocs.org/ntsb-findings/04013020): Organizational issues › Development · Manufacturer; cases with it: [Dehavilland DHC-3, 1 case](https://openairdocs.org/ntsb-findings/04013020/cases.md?model=2802412), [All aircraft, 15 cases](https://openairdocs.org/ntsb-findings/04013020/cases.md)
- [Maintenance: installation](https://openairdocs.org/ntsb-findings/02062035): Personnel issues › Task performance · Maintenance personnel; cases with it: [Dehavilland DHC-3, 1 case](https://openairdocs.org/ntsb-findings/02062035/cases.md?model=2802412), [All aircraft, 371 cases](https://openairdocs.org/ntsb-findings/02062035/cases.md)
- [Policy/procedure: adequacy of policy/proc](https://openairdocs.org/ntsb-findings/04021015): Organizational issues › Management · Maintenance provider; cases with it: [Dehavilland DHC-3, 2 cases](https://openairdocs.org/ntsb-findings/04021015/cases.md?model=2802412), [All aircraft, 106 cases](https://openairdocs.org/ntsb-findings/04021015/cases.md)
- [Documentation/record keeping: maintenance records](https://openairdocs.org/ntsb-findings/04033025): Organizational issues › Support/oversight/monitoring · Maintenance provider; cases with it: [Dehavilland DHC-3, 1 case](https://openairdocs.org/ntsb-findings/04033025/cases.md?model=2802412), [All aircraft, 16 cases](https://openairdocs.org/ntsb-findings/04033025/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Enroute: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Dehavilland DHC-3, 3 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=2802412), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md)

## Factual narrative

On September 4, 2022, about 1509 Pacific daylight time, a float-equipped de Havilland DHC-3 (Otter), N725TH, was destroyed when it impacted the water in Mutiny Bay, near Freeland, Washington, and sank. The pilot and nine passengers were fatally injured. The airplane was owned by Northwest Seaplanes, Inc., and operated as a Title 14 Code of Federal Regulations (CFR) Part 135 scheduled passenger flight by West Isle Air dba Friday Harbor Seaplanes. The flight originated at Friday Harbor Seaplane Base (W33), Friday Harbor, Washington, with an intended destination of Will Rogers Wiley Post Memorial Seaplane Base (W36), Renton, Washington. Visual meteorological conditions prevailed at the time of the accident.

## Aircraft

- Registration: [N725TH](https://openairdocs.org/deregistered/N725TH-2024-03-25), registration cancelled 2024-03-25, S/N 466, built 1967 (OpenAirDocs)
- Reported make and model: DEHAVILLAND DHC-3
- Registry model: [Dehavilland DHC-3](https://openairdocs.org/model/dehavilland-dhc-3) (registry code 2802412) (OpenAirDocs)
- Registry engine: [Walter M601 series](https://openairdocs.org/engine/walter-m601-series) (registry code 64003, turbo-prop) (OpenAirDocs)
- Category: Airplane
- Serial number: 466
- Year built: 1967
- Airframe hours: 24430
- Engines: General Electric H80-200 777 horsepower turbo prop
- Damage: Destroyed
- Flight: Part 135
- Operator: West Isle Air, doing business as Friday Harbor Seaplanes
- Registered owner: Northwest Seaplanes Inc
- Airworthiness certificate: Standard, Commuter
- Last inspection: 100 hour, September 1, 2022, 11 hours before
- Departed: W33, Friday Harbor, WA
- Destination: RNT, Renton, WA
- Flight plan: Company VFR
- Equipment: ADS-B

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 43; injuries: fatal; commercial; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review July 29, 2022; seat: left; toxicology performed; flight hours: 3,686 total, 1,300 in this make and model, 297 in the last 90 days, 111 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 310° at 10 knots
- Visibility: 10 statute miles
- Lowest ceiling: 9,000 ft broken
- Temperature: 68 °F, dew point 57 °F
- Altimeter: 30.02 inHg
- Turbulence: Unknown
- Observed at: K0S9, 10 nm away
- METAR: K0S9 042215Z AUTO 31010KT 10SM FEW040 FEW075 BKN090 20/14 A3002 RMK AO2

## 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 20220904020609A](https://openairdocs.org/incident/20220904020609A), Sep 4, 2022: Dehavilland DHC-3, Mutiny Bay, WA, Destroyed, 10 fatal. During the examination of the airplane wreckage, the investigative team found that the clamp nut that attaches the top eye end and bearing assembly of the…

## Docket (66 files)

The files NTSB released with the investigation on August 31, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=105855. 833 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15437685&FileExtension=pdf&FileName=6120.1%20Pilot_Operator%20Aircraft%20Accident_Incident%20Report_print2_Redacted-Rel.pdf
- Aviation accident report AIR-22-08 (investigative update) (item 2, PDF, 7 pages, 671 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14805890&FileExtension=pdf&FileName=AIR-22-08-Rel.pdf
- Memorandum for record - update on FAA airworthiness directive 2022-23-08 (one time inspection of actuator) (item 3, PDF, 1 page, 196 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16059807&FileExtension=pdf&FileName=01-04%20%20MFR%20-%20FAA%20Update%20on%20Responses%20to%20AD-2022-23-08-Rel.pdf
- Weather factual report (item 4, PDF, 30 pages, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14808576&FileExtension=pdf&FileName=DCA22MA193_weatherfactualSuffernfinal-Rel.pdf
- Weather attachment 1 (item 5, XLSX, 20 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14808188&FileExtension=xlsx&FileName=attachment1_F3783-Rel.xlsx
- Weather attachment 2 (item 6, XLSX, 20 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14808056&FileExtension=xlsx&FileName=attachment2_C5456-Rel.xlsx
- Weather attachment 3 (item 7, GIF, 8.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14808586&FileExtension=gif&FileName=attachment3_animation_SAT_VIS_2131to2231utc_CODNEXLAB-GOES-West-local-Seattle-02-22_31Z-20220904_map-id_-13-1n-10-100-Rel.gif
- Weather attachment 4 (item 8, GIF, 20.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14808765&FileExtension=gif&FileName=attachment4_animation_wxradar_0_5degrees_2117to2225utc-Rel.gif
- Weather attachment 5 (item 9, GIF, 20.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14808198&FileExtension=gif&FileName=attachment5_animation_wxradar_0_5degrees_CC_2117to2225utc-Rel.gif
- Weather attachment 6 (item 10, PDF, 7 pages, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14808066&FileExtension=pdf&FileName=attachment6_GFA-Rel.pdf
- Weather attachment 7 (item 11, MP4, 113 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14807628&FileExtension=mp4&FileName=attachment7_904Pano-Rel.mp4
- Weather attachment 8 (item 12, PDF, 1 page, 62 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14808742&FileExtension=pdf&FileName=attachment8_witnessinfoDCA22FA193_Redacted-Rel.pdf
- Weather attachment 9 (item 13, PDF, 2 pages, 145 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14808041&FileExtension=pdf&FileName=attachment9_dca22ma193foreflight_Redacted-Rel.pdf
- Witness factual report (item 14, PDF, 4 pages, 127 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15188582&FileExtension=pdf&FileName=Witness%20Factual%20Report-Rel.pdf
- Witness interviews and statements (item 15, PDF, 73 pages, 13.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15189201&FileExtension=pdf&FileName=Witness%20interviews%20and%20statements_Redacted-Rel.pdf
- C bard witness video 1 (item 16, MOV, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15189350&FileExtension=MOV&FileName=C%20Bard%20video%201-Rel.MOV
- C bard witness video (item 17, MOV, 826 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15189360&FileExtension=MOV&FileName=C%20Bard%20video%202-Rel.MOV
- C bard witness video 2 (item 18, MOV, 982 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15189136&FileExtension=MOV&FileName=C%20Bard%20video%203-Rel.MOV
- C baker witness video (item 19, MP4, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15187924&FileExtension=MP4&FileName=IMG_9943-Rel.MP4
- D goodrum witness video 1 (item 20, MP4, 147 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15189211&FileExtension=mp4&FileName=D%20Goodrum%20front%20view-Rel.mp4
- D goodrum witness video 2 (item 21, MP4, 295 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15187934&FileExtension=mp4&FileName=D%20Goodrum%20rear%20view%20Plane%20Crash%20Sound-Rel.mp4
- K reddy witness video (item 22, MOV, 18.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15189221&FileExtension=MOV&FileName=IMG_2696-Rel.MOV
- M stroker witness video (item 23, MOV, 2.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15188995&FileExtension=mov&FileName=Mark%20Stroker%20ring%20video-Rel.mov
- M kelley witness video (item 24, MOV, 26.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15189370&FileExtension=MOV&FileName=M%20Kelley%20video%20water%20taxi-Rel.MOV
- R jensen witness video (item 25, MP4, 930 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15187944&FileExtension=mp4&FileName=Clip%20(September%204%202022%20at%20307%20PM)-Rel.mp4
- Shore video (item 26, AVI, 64.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15437174&FileExtension=avi&FileName=Shore_video-Rel.avi
- Shore video - enlarged (item 27, MOV, 102 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15438042&FileExtension=MOV&FileName=shore_video_enlarged-Rel.MOV
- Airplane performance study (item 28, PDF, 13 pages, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15921081&FileExtension=pdf&FileName=DCA22MA193_airplane_performance_study_v3-Rel.pdf
- FAA ADS-B data (item 29, CSV, 912 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15399425&FileExtension=csv&FileName=45073_20220904213000_Once-Rel.csv
- Search and recovery factual report (item 30, PDF, 19 pages, 20 photos, 4.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15414431&FileExtension=pdf&FileName=DCA22MA193%20Search%20and%20Recovery%20Factual-Rel.pdf
- Operational factors group factual report (item 31, PDF, 22 pages, 776 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15542866&FileExtension=pdf&FileName=DCA22MA193_OPS%20Factual%20Report-Rel.pdf
- Operational factors attachment 1 - interview transcript - west isle air chief pilot (item 32, PDF, 87 pages, 172 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15614100&FileExtension=pdf&FileName=Attachment%201%20-%20Interview%20Transcript%20-%20West%20Isle%20Air%20Chief%20Pilot_Redacted-Rel.pdf
- Operational factors - attachment 2 - interview summaries - FAA poi and previous poi (item 33, PDF, 15 pages, 137 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15707116&FileExtension=pdf&FileName=Attachment%202%20-%20Interview%20summaries%20-%20FAA%20POI%20and%20previous%20POI-Rel.pdf
- Operational factors attachment 3 - west isle air pilot questionnaires (item 34, PDF, 30 pages, 3.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15615461&FileExtension=pdf&FileName=Attachment%203%20-%20West%20Isle%20Air%20Pilot%20Questionnaires_Redacted-Rel.pdf
- Operational factors attachment 4 - interview summary - other airline's pilot (item 35, PDF, 3 pages, 38 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15614920&FileExtension=pdf&FileName=Attachment%204%20-%20Interview%20summary%20-%20Other%20airline%27s%20pilot_Redacted-Rel.pdf
- Operational factors - attachment 5 - de havilland DHC-3 otter flight manual [excerpts] (item 36, PDF, 4 pages, 117 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15593824&FileExtension=pdf&FileName=Attachment%205%20-%20De%20Havilland%20DHC-3%20Otter%20Flight%20Manual%20%5BExcerpts%5D-Rel.pdf
- Operational factors attachment 6 - DHC-3 otter flight manual supplement (FMS#10) [excerpts] (item 37, PDF, 5 pages, 384 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15613625&FileExtension=pdf&FileName=Attachment%206%20-%20DHC-3%20Otter%20Flight%20Manual%20Supplement%20(FMS%2310)%20%5BExcerpts%5D_Redacted-Rel.pdf
- Operational factors - attachment 7 west isle air flight operations manual [excerpts] (item 38, PDF, 9 pages, 857 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15574819&FileExtension=pdf&FileName=Attachment%207%20-%20West%20Isle%20Air%20Flight%20Operartions%20Manual%20%5BExcerpts%5D-Rel.pdf
- Operational factors - attachment 8 west isle air flight training manual [excerpts] (item 39, PDF, 5 pages, 6.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15573167&FileExtension=pdf&FileName=Attachment%208%20-%20West%20Isle%20Air%20Flight%20Training%20Manual%20%5BExcerpts%5D-Rel.pdf
- Operational factors - attachment 9 see gee calculator and instructions - DHC-3 (item 40, PDF, 4 pages, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15575802&FileExtension=pdf&FileName=Attachment%209%20-%20See%20Gee%20Calculator%20and%20Instructions%20-%20DHC-3-Rel.pdf
- Operational factors - attachment 10 fueling information - N725TH (item 41, PDF, 2 pages, 95 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15575736&FileExtension=pdf&FileName=Attachment%2010%20-%20Fueling%20information%20-%20N725TH-Rel.pdf
- Operational factors - attachment 11 pilot training record summary (item 42, PDF, 3 pages, 4.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15574829&FileExtension=pdf&FileName=Attachment%2011%20-%20Pilot%20Training%20Record%20Summary-Rel.pdf
- Operational factors - attachment 12 - statement of party representatives to NTSB investigation (item 43, PDF, 3 pages, 3.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15594511&FileExtension=pdf&FileName=Attachment%2012%20-%20West%20Isle%20Air%20Party%20Forms_Redacted-Rel.pdf
- Operational factual attachment 13 - email from west isle air chief pilot re training dates (item 44, PDF, 3 pages, 187 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15615522&FileExtension=pdf&FileName=Attachment%2013%20-%20Email%20from%20West%20Isle%20Air%20chief%20pilot%20re%20training%20dates_Redacted-Rel.pdf
- Maintenance records (item 45, PDF, 28 pages, 289 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15614409&FileExtension=pdf&FileName=Factual-Rel.pdf
- Maintenance records - errata (item 46, PDF, 2 pages, 70 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16173904&FileExtension=pdf&FileName=Mutiny%20Bay%20Errata-Rel.pdf
- Lubrication intervals diagram (item 47, PDF, 1 page, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15704450&FileExtension=pdf&FileName=Lubrication%20information_annotated-Rel.pdf
- 100 Hour / annual inspection checklist (item 48, PDF, 4 pages, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16024675&FileExtension=pdf&FileName=100%20Hour%20Checklist%20Sept%201%202022_print_Redacted_2-Rel.pdf
- Excerpt from maintenance manual - supplemental inspection and corriosion control program (item 49, PDF, 3 pages, 96 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16109507&FileExtension=pdf&FileName=Excerpts%20from%20PSM%201-3-5%20-%20AMM%20-%20SUPPLEMENTAL%20INSPECTION%20AND%20CORRIOSION%20CONTROL%20PROGRAM-Rel.pdf
- Airworthiness factual report (item 50, PDF, 26 pages, 11 photos, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15437849&FileExtension=pdf&FileName=DCA22MA193%20AW%20Factual-Rel.pdf
- Photographs - wreckage layout - general (item 51, PDF, 6 pages, 5 photos, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16036185&FileExtension=pdf&FileName=06-01%20Photographs-Layout_General-Rel.pdf
- Materials laboratory factual report 23-020 actuator - exemplar (item 52, PDF, 22 pages, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15398839&FileExtension=pdf&FileName=23-020%20actuator%20exemplar%20-%20FINAL-Rel.pdf
- Materials laboratory factual report 23-019 actuator - accident (item 53, PDF, 25 pages, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15664716&FileExtension=pdf&FileName=23-019%20actuator%20-%20accident%20FINAL-Rel.pdf
- Moisture seal position description (item 54, PDF, 8 pages, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16056772&FileExtension=pdf&FileName=Moisture%20Seal%20Position-Rel.pdf
- Materials laboratory factual report 23-021 experiments (item 55, PDF, 22 pages, 260 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15664760&FileExtension=pdf&FileName=23-021%20actuator%20-%20experiments%20%20FINAL-Rel.pdf
- Video demo 1 - lock ring seating test (item 56, MOV, 108 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15619061&FileExtension=MOV&FileName=video%201%20-%20IMG_3568-Rel.MOV
- Video demo 2 - lock ring seating test (item 57, MOV, 130 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15620327&FileExtension=MOV&FileName=video%202%20-%20IMG_3571-Rel.MOV
- Video demo 3 - lock ring seating test (item 58, MOV, 134 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15620224&FileExtension=MOV&FileName=video%203%20-%20IMG_3572-Rel.MOV
- Materials laboratory factual report 23-022 elevator (item 59, PDF, 17 pages, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15295359&FileExtension=pdf&FileName=23-022%20elevator-Rel.pdf
- Materials laboratory factual report 22-023 bottom panel (item 60, PDF, 7 pages, 290 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15294094&FileExtension=pdf&FileName=23-023%20bottom%20panel-Rel.pdf
- Medical factual report (item 61, PDF, 6 pages, 156 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15841749&FileExtension=pdf&FileName=DCA22MA193_MedicalFactualReport-Rel.pdf
- FAA toxicology report - pilot (item 62, PDF, 1 page, 215 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15842633&FileExtension=pdf&FileName=DCA22MA193_Toxicology-Rel.pdf
- 1989 NTSB investigation involving a failed trim actuator (item 63, PDF, 26 pages, 8.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16175883&FileExtension=pdf&FileName=01-02-1989%20NTSB%20Report%20ANC89IA099_NTSB_report-Rel.pdf
- Evidence control form DCA22MA193-STR-001 (item 64, PDF, 1 page, 114 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15613415&FileExtension=pdf&FileName=ECF%20DCA22MA193-STR-001-Rel.pdf
- Evidence control form DCA22MA193-STR-002 (item 65, PDF, 1 page, 114 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15613902&FileExtension=pdf&FileName=ECF%20DCA22MA193-STR-002-Rel.pdf
- Release of aircraft wreckage, NTSB form 6120.15 with attachments (item 66, PDF, 10 pages, 3.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16773908&FileExtension=pdf&FileName=11-01%20-%20NTSB%20Form%206120-15%20Wreckage%20Release%20DCA22MA193_w_attachments_print_Redacted_V2-Rel.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.

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