NTSB Reports
Aviation Safety Intelligence
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.

Get the iPhone App
63k+
Reports indexed
1940-2026
Coverage
Recent
Last data refresh
Featured Report

Loading…

Loading featured report…

Loading…
Open 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…

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 manufacturers

Airports

More airports

Operators

More operators

About

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

March 31, 1990 · Hiller UH-12D · N94496

Soddy-Daisy, TN

Overview

Report Status
Probable Cause
Event Type
Accident
Date
March 31, 1990
Injury Outcomes
3 injuries (1 fatality, 1 serious injury, 1 minor injury)
Location
Soddy-Daisy, TN
Aircraft
Hiller UH-12D
Tail Number
N94496
Injuries
Fatal
Aircraft Damage
Substantial
NTSB Number
ATL90FA089

SHORTLY AFTER TAKEOFF, THE PILOT OBSERVED DECREASING ENGINE AND ROTOR RPM. HE LOWERED THE COLLECTIVE, BUT THE RPM DID NOT RETURN. THE HELICOPTER COLLIDED WITH TREES AND TERRAIN DURING THE FORCED LANDING ATTEMPT. AN INSPECTION OF THE HELICOPTER REVEALED THAT THE COLLECTIVE PITCH PUSH ROD (ADJUSTABLE) HAD FAILED IN FATIGUE. THE LAST RECORDED MAINTENANCE WAS PERFORMED ON FEBRUARY 22, 1988, MORE THAN TWO YEARS PRIOR TO THE ACCIDENT. THE PILOT/OWNER WAS OPERATING THE HELICOPTER WITH A STUDENT PILOT CERTIFICATE AND WAS CARRYING PASSENGERS.

NTSB Probable Cause

FATIGUE INDUCED FAILURE OF THE COLLECTIVE PITCH PUSH ROD (ADJUSTABLE) DURING FLIGHT, AND THE FAILURE OF THE PILOT TO PROVIDE ROUTINE MAINTENANCE. THE PILOT'S LACK OF EXPEREINCE AND HIS FAILURE TO OBTAIN REQUIRED TRAINING AND CERTIFICATION WERE FACTORS IN THE ACCIDENT.

Full Narrative

SHORTLY AFTER TAKEOFF, THE PILOT OBSERVED DECREASING ENGINE AND ROTOR RPM. HE LOWERED THE COLLECTIVE, BUT THE RPM DID NOT RETURN. THE HELICOPTER COLLIDED WITH TREES AND TERRAIN DURING THE FORCED LANDING ATTEMPT. AN INSPECTION OF THE HELICOPTER REVEALED THAT THE COLLECTIVE PITCH PUSH ROD (ADJUSTABLE) HAD FAILED IN FATIGUE. THE LAST RECORDED MAINTENANCE WAS PERFORMED ON FEBRUARY 22, 1988, MORE THAN TWO YEARS PRIOR TO THE ACCIDENT. THE PILOT/OWNER WAS OPERATING THE HELICOPTER WITH A STUDENT PILOT CERTIFICATE AND WAS CARRYING PASSENGERS.

Flight

Event TypeAccident
Event Time13:38 EST
Nearest Airport0nm N
Runway0
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo

Aircraft

AircraftHiller UH-12D
Tail NumberN94496
Aircraft CategoryHeli
DamageSubstantial
Operating RulePart 91
Engines1
Engine TypeReciprocating
Engine DetailsLycoming · O-435-A1C · Reciprocating · 250
Seats3

People & Injuries

Injury Summary3 injuries (1 fatality, 1 serious injury, 1 minor injury)
Fatal1
Serious1
Minor1
Uninjured0
Total3
Crew 1Age 41 · Third Class

Conditions

ConditionsVMC
LightDaylight
Wind180° @ 5 kt
Visibility12 sm
CeilingNone
Temperature / Dew Point70 F / 57
Altimeter29.00 inHg
Observation Time18:50
Weather SourceWFAC

External Links

Appendix: Source Data