Overall Trends
Total, fatal, and serious accidents in the selected range.
Premium research interface
The modern interface for aviation safety intelligence.
Search investigations, review source evidence, monitor watched reports, and trace long-term patterns from one calm, data-first workspace.
63k+
Reports indexed
1940-2026
Coverage
Recent
Last data refresh
Search everything
Fast key and full-text search with live filters, watches, and precise metadata.
Use quotes for exact phrase matches (for example "fuel selector valve").
Featured Report
Safety trends by operating rule
Track fatal and non-fatal accident patterns across Part 91, Part 135, and Part 121 operations.
Loading trend charts…
High-signal investigations
Major cases, deep-report coverage, and investigation media across decades of NTSB history.
Browse the aviation graph
Move quickly by aircraft, airport, operator, and time with indexes built for research, not wandering.
Last Data Update
By Decade
By Month
Aircraft Manufacturer
More manufacturersAirports
More airportsOperators
More operatorsAbout
Aviation safety reports, made easier to study
NTSB Reports is an independent research and search tool for public aviation accident and incident records. It brings NTSB aviation reports, structured fields, docket files, extracted figures, photos, videos, and update history into one searchable interface.
The goal is practical safety education: make it faster to find relevant investigations, compare similar events, review factual records, and understand the evidence behind probable-cause and preliminary reports.
The investigative work and source records belong to the National Transportation Safety Board and the published investigation record. This site is not affiliated with or endorsed by the NTSB.
FAQs
NTSB Report
November 26, 1990 · Hughes 369D · N1106Z
Mulina, OR
Overview
Report Status
Probable Cause
Event Type
Accident
Date
November 26, 1990
Injury Outcomes
No injuries (1 uninjured)
Location
Mulina, OR
Aircraft
Hughes 369D
Tail Number
N1106Z
Operator
Temesco Helicopters
Injuries
None
Aircraft Damage
Substantial
NTSB Number
SEA91LA023
THE HUGHES 369D HELICOPTER CRASHED WHILE CONDUCTING CHRISTMAS TREE EXTERNAL-LOAD OPERATIONS WHEN A CHOKER ATTACHED TO A LONG- LINE EXTERNAL HOOK SNAGGED ON AN UNIDENTIFIED OBJECT AND SNAPPED THE REMOTE HOOK INTO THE MAIN ROTOR SYSTEM. ACCORDING TO THE PILOT, A POWER-ON AUTOROTATION WAS ATTEMPTED, BUT DUE TO LOW ROTOR RPM, THE MAIN BLADES CHOPPED OFF THE TAIL BOOM.
NTSB Probable Cause
IN-FLIGHT COLLISION WITH A REBOUNDING LONG-LINE, WHICH CAUSED MAIN-ROTOR RPM DECAY AND TAIL-BOOM SEPARATION, COMPROMISING THE PILOT'S ABILITY TO SUCCESSFULLY ACCOMPLISH AN ATTEMPTED AUTOROTATION.
Full Narrative
THE HUGHES 369D HELICOPTER CRASHED WHILE CONDUCTING CHRISTMAS TREE EXTERNAL-LOAD OPERATIONS WHEN A CHOKER ATTACHED TO A LONG- LINE EXTERNAL HOOK SNAGGED ON AN UNIDENTIFIED OBJECT AND SNAPPED THE REMOTE HOOK INTO THE MAIN ROTOR SYSTEM. ACCORDING TO THE PILOT, A POWER-ON AUTOROTATION WAS ATTEMPTED, BUT DUE TO LOW ROTOR RPM, THE MAIN BLADES CHOPPED OFF THE TAIL BOOM.
Flight
Event TypeAccident
Event Time07:30 PST
Nearest Airport0nm N
Runway0
Runway Length0
Runway Width0
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftHughes 369D
Tail NumberN1106Z
Aircraft CategoryHeli
DamageSubstantial
OperatorTemesco Helicopters
Operating RulePart 133
Engines1
Engine TypeTurboshaft
Engine DetailsAllison · 250-C20 · Turboshaft · 420
Seats5
People & Injuries
Injury SummaryNo injuries (1 uninjured)
Fatal0
Serious0
Minor0
Uninjured1
Total1
Crew 1Age 45 · Second Class
Conditions
ConditionsVMC
LightDaylight
WindCalm
Visibility10 sm
CeilingOvercast 2500 ft
Temperature / Dew Point0 C / 0 C
Altimeter0
Weather SourcePILO