NTSB CAROL · Event
Event DEN90FA172
Aircraft involved
Probable cause & findings
A MAIN ROTOR HEAD BLADE DAMPENER FAILURE. A FACTOR IN THE ACCIDENT WAS THE SUBSEQUENT FAILURE OF A BLADE RESTRAINING CABLE.
Factual narrative
APPROXIMATELY 2 MINUTES INTO THE FLIGHT, THE PILOT EXPERIENCED A SLIGHT 1 TO 1 VIBRATION THROUGH THE CYCLIC. THIS TYPE VIBRATION IS ASSOCIATED WITH MAIN ROTOR DAMPERS AND THE PILOT 'STIRRED' THE CYCLIC IN AN EFFORT TO PURGE AIR OUT OF THE BLADE DAMPERS. THIS ELIMINATED THE PROBLEM, HOWEVER, IT RECURRED AND COULD NOT BE ELIMINATED. THE VIBRATION INCREASED TO THE POINT OF LOSS OF CONTROL. AN EMERGENCY LANDING WAS ATTEMPTED WITH TOUCHDOWN OCCURRING AT ABOUT 60 KNOTS. THE HELICOPTER CAME TO REST INVERTED AND WAS LARGELY CONSUMED BY POST-IMPACT FIRE. METALLURGICAL ANALYSIS ON A FAILED BLADE RESTRAINING CABLE REVEALED A CATASTROPHIC FAILURE IN A LOW CYCLE FATIGUE MODE CONSISTENT WITH A SECONDARY CAUSE, AND DUE TO SHORT TERM VIBRATIONS. IN ADDITION TO FATIGUE, THERE WAS EVIDENCE OF PLASTIC DEFORMATION DUE TO VIBRATORY LOADS FROM THE DAMPER SYSTEMS. FIRE DAMAGE PREVENTED ADDITIONAL FAILURE ANALYSIS. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_1990_DEN90FA172.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
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Related research
What the literature says.
Academic papers and agency reports matching this event's aircraft type or causal vocabulary (loss of control). Sourced from NASA NTRS, NTSB Safety Studies, FAA CAMI, AOPA Air Safety Institute, Embry-Riddle Scholarly Commons, arXiv, and the Semantic Scholar academic graph.
- Embry-Riddle Scholarly Commons 2025 · Journal article (JAAER)
A Scoping Review of Aviation Loss of Control Inflight Research
Loss of control – inflight (LOC-I) contributes to aircraft accidents at unacceptably high rates. Significant industry efforts and research have aimed to improve LOC-I prevention, detection, and recove…
- SKYbrary (Eurocontrol) 2024 · SKYbrary article
Loss of Control In-Flight (LOC-I) — SKYbrary Knowledge Base
SKYbrary comprehensive knowledge-base entry on Loss of Control In-Flight — definitions, contributing factors, accident case studies (Air France 447, Colgan 3407), and prevention strategies.
- NTSB Aircraft Accident Reports 2022 · Accident report
Loss of Control on Takeoff in Icing Conditions — Citation 560XL
Cessna Citation 560XL fatal takeoff icing accident, March 2018. Investigation of a Citation 560XL loss-of-control takeoff accident in icing conditions.
- Semantic Scholar 2021 · Article (Aviation)
ANALYSIS OF GENERAL AVIATION FIXED-WING AIRCRAFT ACCIDENTS INVOLVING INFLIGHT LOSS OF CONTROL USING A STATE-BASED APPROACH
Inflight loss of control (LOC-I) is a significant cause of General Aviation (GA) fixed-wing aircraft accidents. The United States National Transportation Safety Board’s database provides a rich source…
- NASA NTRS 2021 · Presentation
Use of Design of Experiments in Determining Neural Network Architectures for Loss of Control Detection
Abstract—We describe empirical methods for selecting a neural network architecture to implement belief state inference on generic commercial transport aircraft.
- NASA NTRS 2021 · Conference Paper
Use of Design of Experiments in Determining Neural Network Architectures for Loss of Control Detection
We describe empirical methods for selecting a neural network architecture to implement belief state inference on generic commercial transport aircraft.
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