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
June 17, 1991 · Robinson R-22B · N4034K
Phoenix, AZ
Overview
Report Status
Probable Cause
Event Type
Accident
Date
June 17, 1991
Injury Outcomes
No injuries (2 uninjured)
Location
Phoenix, AZ
Aircraft
Robinson R-22B
Tail Number
N4034K
Operator
Arizona Wing and Rotor
Injuries
None
Aircraft Damage
Destroyed
NTSB Number
LAX91LA264
THE INSTRUCTOR SAID THAT THE STUDENT WAS PERFORMING AUTOROTATIONS WITH POWER RECOVERIES. THE INSTRUCTOR STATED THAT DURING THE LAST AUTOROTATION SHE HEARD THE LOW ROTOR SPEED WARNING HORN AND INITIATED A THROTTLE INCREASE TO RECOVER. ACCORDING TO THE INSTRUCTOR, THE ENGINE AND ROTOR FAILED TO RESPOND TO THE THROTTLE INCREASE AND THE HELICOPTER LANDED HARD. A POST CRASH FIRE IGNITED AND CONSUMED THE AIRCRAFT. FAA INSPECTORS EXAMINED THE WRECKAGE AND FOUND NO EVIDENCE OF A PRE IMPACT MECHANICAL MALFUNCTION OR FAILURE IN THE SURVIVING COMPONENTS.
NTSB Probable Cause
THE FAILURE OF THE STUDENT TO MAINTAIN THE PROPER ROTOR RPM WHILE PERFORMING A PRACTICE AUTOROTATION, AND, THE FAILURE OF THE FLIGHT INSTRUCTOR TO PROPERLY SUPERVISE THE CONDUCT OF THE FLIGHT AND TO TAKE TIMELY CORRECTIVE ACTION.
Full Narrative
THE INSTRUCTOR SAID THAT THE STUDENT WAS PERFORMING AUTOROTATIONS WITH POWER RECOVERIES. THE INSTRUCTOR STATED THAT DURING THE LAST AUTOROTATION SHE HEARD THE LOW ROTOR SPEED WARNING HORN AND INITIATED A THROTTLE INCREASE TO RECOVER. ACCORDING TO THE INSTRUCTOR, THE ENGINE AND ROTOR FAILED TO RESPOND TO THE THROTTLE INCREASE AND THE HELICOPTER LANDED HARD. A POST CRASH FIRE IGNITED AND CONSUMED THE AIRCRAFT. FAA INSPECTORS EXAMINED THE WRECKAGE AND FOUND NO EVIDENCE OF A PRE IMPACT MECHANICAL MALFUNCTION OR FAILURE IN THE SURVIVING COMPONENTS.
Flight
Event TypeAccident
Event Time08:00 MST
Nearest Airport0nm
Runway0
Flight Plan FiledNone
Aircraft FireGrd
Aircraft ExplosionGrd
Aircraft
AircraftRobinson R-22B
Tail NumberN4034K
Aircraft CategoryHeli
DamageDestroyed
OperatorArizona Wing and Rotor
Operating RulePart 91
Engines1
Engine TypeReciprocating
Engine DetailsLycoming · O-320-A2B · Reciprocating · 150
Seats2
People & Injuries
Injury SummaryNo injuries (2 uninjured)
Fatal0
Serious0
Minor0
Uninjured2
Total2
Crew 1Age 25 · Second Class
Conditions
ConditionsVMC
LightDaylight
WindGusting 40 kt
Visibility50 sm
CeilingNone
Temperature / Dew Point0 C / 0 C
Altimeter0
Weather SourcePILO