NTSB CAROL · Event
Event MKC90LA144
Registry · N8117
FAA Aircraft Registry record.
Make / Model
BELL 47D1
Year of manufacture
1967 · 23 years old at event
TCDS
H-1 · SCOTT'S-BELL 47 INC
Engine
LYCOMING VO-435 SERIES (260 hp)
Seats / Engines
3 seats · 1 engine
Last airworthiness date
19900530
ADS-B equipped
Yes — Mode-S AB1060
Registrant of record
HENRY MARK A
Source: FAA Aircraft Registry (releasable master file).
Aircraft involved
Probable cause & findings
TAIL ROTOR CABLE DISENGAGEMENT DUE TO INADEQUATE MAINTENANCE.
Factual narrative
THE COMMERCIAL PLT SAID THAT WHILE CONDUCTING AN AERIAL APPLICATION OPERATION HE FELT A VIBRATION IN THE AIRCRAFT. HE SAID THAT THERE WAS NO LEFT OR RIGHT PEDAL RESPONSE IMMEDIATELY AFTERWARD. HE INITIATED A RIGHT TURN TO RETURN TO THE AIRSTRIP AND THE HELICOPTER WOULD NOT RECOVER. IT CONTINUED TURNING RIGHT AND DESCENDED UNTIL IT COLLIDED WITH THE TERRAIN. POST-ACCIDENT INVESTIGATION REVEALED THE TAIL ROTOR CABLE HAD BECOME DISENGAGED FROM THE TAIL ROTOR PITCH DRUM AND HAD WRAPPED AROUND THE FLANGE OF THE PITCH CHANGE DRUM. THE TAIL ROTOR BLADES WERE LOCKED IN THE RIGHT PEDAL POSITION. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_1990_MKC90LA144.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 (maintenance). 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 2026 · Journal article (IJAAA)
From Reactive to Predictive: A hybrid Trust-Mediated Adoption Framework for Data-Driven Maintenance in Distributed-Authority Aviation Environments
Modern aviation maintenance operates within increasingly data-intensive technological environments, yet the operational integration of predictive maintenance into routine decision-making remains incon…
- Semantic Scholar 2025 · Article (Applied Sciences)
Decision-Making Framework for Aviation Safety in Predictive Maintenance Strategies
The implementation of predictive maintenance (PM) in aviation presents unique challenges due to strict safety requirements, complex operational environments, and regulatory constraints.
- Embry-Riddle Scholarly Commons 2024 · Journal article (JAAER)
Low-Resource Automatic Speech Recognition Domain Adaptation – A Case-Study in Aviation Maintenance
With timeliness and efficiency being critical in the aviation maintenance industry, the need has been growing for smart technological solutions that optimize and streamline the different underlying ta…
- Embry-Riddle Scholarly Commons 2024 · Journal article (JAAER)
A New Trajectory in UAV Safety: Leveraging Reinforcement Learning for Distance Maintenance Under Wind Variations
In the field of aviation, safety is a critical cornerstone, and the operation of Unmanned Aerial Vehicle (UAV) systems is deeply connected with this principle.
- Embry-Riddle Scholarly Commons 2024 · Journal article (IJAAA)
Just Culture in Aviation: A Metaphorical Study on Aircraft Maintenance Students
Just Culture, a sub-dimension of safety culture, has been a prominent and debated topic in aviation safety in recent years.
- Embry-Riddle Scholarly Commons 2024 · Journal article (IJAAA)
Performance PRISM: A Comprehensive Framework For Performance Measurement In Aircraft Maintenance
Aircraft maintenance is governed by rigorous safety requirements and high operational complexity, demanding robust performance measurement frameworks to ensure optimal maintenance practices.
Browse the full corpus — academia portal ↗