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
September 2, 1987 · Aero Commander 690 · N9168N
Appleton, WI
Overview
Report Status
Preliminary report
Event Type
Accident
Date
September 2, 1987
Injury Outcomes
No injuries (5 uninjured)
Location
Appleton, WI
Aircraft
Aero Commander 690
Tail Number
N9168N
Operator
Maxair
Injuries
None
Aircraft Damage
Substantial
NTSB Number
CHI87LA200
THE PLT RPRTD THAT AFTER THE ACFT WAS AT CRUISE FLT, THERE WAS A RAPID LOSS OF HYDRAULIC PRESSURE. HE RETURNED TO THE DEP ARPT, BUT WAS UNABLE TO GET THE LEFT MAIN GEAR TO LOCK DOWN. SUBSEQUENTLY, THE LEFT MAIN GEAR COLLAPSED WHEN THE ACFT WAS LANDED. AN INVESTIGATION REVEALED A HYDRAULIC LINE IN THE LEFT WING HAD FAILED WHICH HAD ALLOWED A LOSS OF HYDRAULIC FLUID & PRESSURE. ALSO, THERE WAS A STICKING PRIORITY VALVE. WITH THESE PROBLEMS, THE GEAR COULD NOT BE EXTENDED WITH EITHER THE NORMAL OR EMERG SYS.
Full Narrative
THE PLT RPRTD THAT AFTER THE ACFT WAS AT CRUISE FLT, THERE WAS A RAPID LOSS OF HYDRAULIC PRESSURE. HE RETURNED TO THE DEP ARPT, BUT WAS UNABLE TO GET THE LEFT MAIN GEAR TO LOCK DOWN. SUBSEQUENTLY, THE LEFT MAIN GEAR COLLAPSED WHEN THE ACFT WAS LANDED. AN INVESTIGATION REVEALED A HYDRAULIC LINE IN THE LEFT WING HAD FAILED WHICH HAD ALLOWED A LOSS OF HYDRAULIC FLUID & PRESSURE. ALSO, THERE WAS A STICKING PRIORITY VALVE. WITH THESE PROBLEMS, THE GEAR COULD NOT BE EXTENDED WITH EITHER THE NORMAL OR EMERG SYS.
Flight
Event TypeAccident
Event Time12:15 CDT
Nearest AirportOutagamie County (0nm N)
Runway3
Runway Length7001 ft
Runway Width150 ft
Flight Plan FiledIFR
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftAero Commander 690
Tail NumberN9168N
Aircraft CategoryAir
DamageSubstantial
OperatorMaxair
Operating RulePart 135
Engines2
Engine TypeTurboprop
Engine DetailsAiresearch · TPE-331 · Turboprop · 718
Seats8
People & Injuries
Injury SummaryNo injuries (5 uninjured)
Fatal0
Serious0
Minor0
Uninjured5
Total5
Crew 1Age 45 · Second Class
Conditions
ConditionsVMC
LightDaylight
Wind330° @ 6 kt
Visibility20 sm
CeilingNone
Temperature / Dew Point63 F / 0 C
Altimeter30.00 inHg
Observation Time17:20
Weather SourceWFAC