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
December 9, 1989 · Hughes 369HS · N9161F
Waimea, HI
Overview
Report Status
Probable Cause
Event Type
Accident
Date
December 9, 1989
Injury Outcomes
No injuries (5 uninjured)
Location
Waimea, HI
Aircraft
Hughes 369HS
Tail Number
N9161F
Operator
Air Kaui
Injuries
None
Aircraft Damage
Substantial
NTSB Number
LAX90LA050
THE CERTIFICATED AIR LINE TRANSPORT PILOT WAS CONDUCTING A HELICOPTER SIGHTSEEING FLIGHT WITH 4 PASSENGERS WHEN THE ENGINE SUDDENLY LOST POWER. THE PILOT MADE AN EMERGENCY AUTOROTATION TO THE BOTTOM OF A SMALL RIVER BOTTOM. WHILE LANDING, THE HELICOPTER ROLLED OVER. EXAMINATION OF THE ENGINE SHOWED THAT THE FUEL CONTROL PC TUBE TO THE POWER TURBINE GOVERNOR HAD FRACTURED, CAUSING THE ENGINE TO GO TO A FLIGHT IDLE CONDITION. THIS TUBE WAS FOUND TO EXCEED THE SPECIFIED REQUIRED LENGTH OF MANUFACTURE. DURING INSTALLATION, THE TUBE WAS BENT BY COMPANY MAINTENANCE PERSONNEL TO FIT. METALLURGICAL EXAM DISCLOSED A FRACTURE DUE TO FATIGUE NEAR THE FUEL CONTROL END. THIS FATIGUE WAS INTRODUCED BY BENDING STRESSES IN THE TUBE.
NTSB Probable Cause
THE IMPROPER INSTALLATION OF THE PC TUBE BY COMPANY MAINTENANCE PERSONNEL, WHICH RESULTED IN FATIGUE FAILURE OF THE TUBE DUE TO INDUCED BENDING STRESSES.
Full Narrative
THE CERTIFICATED AIR LINE TRANSPORT PILOT WAS CONDUCTING A HELICOPTER SIGHTSEEING FLIGHT WITH 4 PASSENGERS WHEN THE ENGINE SUDDENLY LOST POWER. THE PILOT MADE AN EMERGENCY AUTOROTATION TO THE BOTTOM OF A SMALL RIVER BOTTOM. WHILE LANDING, THE HELICOPTER ROLLED OVER. EXAMINATION OF THE ENGINE SHOWED THAT THE FUEL CONTROL PC TUBE TO THE POWER TURBINE GOVERNOR HAD FRACTURED, CAUSING THE ENGINE TO GO TO A FLIGHT IDLE CONDITION. THIS TUBE WAS FOUND TO EXCEED THE SPECIFIED REQUIRED LENGTH OF MANUFACTURE. DURING INSTALLATION, THE TUBE WAS BENT BY COMPANY MAINTENANCE PERSONNEL TO FIT. METALLURGICAL EXAM DISCLOSED A FRACTURE DUE TO FATIGUE NEAR THE FUEL CONTROL END. THIS FATIGUE WAS INTRODUCED BY BENDING STRESSES IN THE TUBE.
Flight
Event TypeAccident
Event Time15:30 HST
Nearest Airport0nm N
Runway0
Runway Length0
Runway Width0
Flight Plan FiledCvfr
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftHughes 369HS
Tail NumberN9161F
Aircraft CategoryHeli
DamageSubstantial
OperatorAir Kaui
Operating RulePart 91
Engines1
Engine TypeTurboshaft
Engine DetailsAllison · 250-C20 · Turboshaft · 375
Seats5
People & Injuries
Injury SummaryNo injuries (5 uninjured)
Fatal0
Serious0
Minor0
Uninjured5
Total5
Crew 1Age 39 · Second Class
Conditions
ConditionsVMC
LightDaylight
WindCalm
Visibility15 sm
CeilingNone
Temperature / Dew Point0 C
Altimeter0
Weather SourcePILO