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
May 13, 1989 · Hiller UH-12E · N5594N
Mack, CO
Overview
Report Status
Probable Cause
Event Type
Accident
Date
May 13, 1989
Injury Outcomes
1 injury (1 serious injury)
Location
Mack, CO
Aircraft
Hiller UH-12E
Tail Number
N5594N
Injuries
Serious
Aircraft Damage
Substantial
NTSB Number
DEN89DTM02
THE PILOT STATED THAT DURING A SWATH RUN HE LET THE HELICOPTER GET TOO LOW AND THE SKIDS CONTACTED THE ALFALFA CROP FOLLOWED BY THE SPRAY APPARATUS. THE PILOT WAS UNABLE TO GAIN ALTITUDE AND THE HELICOPTER CONTINUED TO DESCEND INTO THE GROUND AND ROLLED OVER. AN EYE-WITNESSES CONCURRED WITH THE PILOT'S STATEMENT BUT DECLINED TO GIVE A WRITTEN STATEMENT.
NTSB Probable Cause
THE PILOT'S FAILURE TO MAINTAIN PROPER ALTITUDE DURING A SWATH RUN.
Full Narrative
THE PILOT STATED THAT DURING A SWATH RUN HE LET THE HELICOPTER GET TOO LOW AND THE SKIDS CONTACTED THE ALFALFA CROP FOLLOWED BY THE SPRAY APPARATUS. THE PILOT WAS UNABLE TO GAIN ALTITUDE AND THE HELICOPTER CONTINUED TO DESCEND INTO THE GROUND AND ROLLED OVER. AN EYE-WITNESSES CONCURRED WITH THE PILOT'S STATEMENT BUT DECLINED TO GIVE A WRITTEN STATEMENT.
Flight
Event TypeAccident
Event Time07:48 MDT
Nearest Airport0nm N
Runway0
Runway Length0
Runway Width0
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftHiller UH-12E
Tail NumberN5594N
Aircraft CategoryHeli
DamageSubstantial
Operating RulePart 137
Engines1
Engine TypeReciprocating
Engine DetailsLycoming · VO-540-C2A · Reciprocating · 305
Seats3
People & Injuries
Injury Summary1 injury (1 serious injury)
Fatal0
Serious1
Minor0
Uninjured0
Total1
Crew 1Age 48 · Second Class
Conditions
ConditionsVMC
LightDaylight
Wind310° @ 3 kt
Visibility9 sm
CeilingBroken clouds 9000 ft
Temperature / Dew Point48 / 36 C
Altimeter29.00 inHg
Observation Time13:52
Weather SourceWFAC