NYC98LA006
1997-10-05 · BENNINGTON, Vermont, United States · None · 1 aircraft · Status: Completed
Airport 5B5
Current FAA registration · N49983
- Make / Model
- HILLER UH-12C
- Seats / Engines
- 4 seats · 1 engine
- Last airworthiness date
- 19790522
- ADS-B equipped
- Yes — Mode-S A63513
Source: FAA Aircraft Registry (releasable master file).
Aircraft involved
Probable cause & findings
The failure of the cyclic control due to an improper modification by the pilot/owner.
Factual narrative
On October 5, 1997, about 1230 eastern daylight time, a Hiller UH-12C, N49983, was substantially damaged when it rolled over while hovering at the William H. Morse State Airport (5B5), Bennington, Vermont. The certificated flight instructor and student pilot were not injured. Visual meteorological conditions prevailed for the local instructional flight that originated at 5B5, about 1210. No flight plan had been filed for the flight conducted under 14 CFR Part 91. In the NTSB Form 6120.1/2, the certificated flight instructor (CFI)/owner stated that they had been hovering over a grass area, when the loss of control occurred and the helicopter rolled right onto it's side. According to a Federal Aviation Administration (FAA) Inspector, the CFI had been demonstrating how to hover a helicopter to a student pilot. While the student pilot was attempting to hover the helicopter, it began to roll right. When the CFI took hold of his controls, the top of his cyclic stick detached. The helicopter then rolled right and collided with the ground. Examination of the helicopter by the FAA Inspector revealed the helicopter's cyclic stick had been replaced with a military style cyclic. According to the FAA Inspector, the owner reported that the cyclic had been cut down by removing a section of the cyclic. The top of the cyclic detached at the repaired joint. A review of the maintenance records did not reveal who or when the modification was performed. The certificated flight instructor (CFI)/owner had been demonstrating how to hover a helicopter to a student pilot. When the student pilot attempted to hover the helicopter, it began to roll right. The CFI then took hold of his controls, and the top of his cyclic stick detached. The helicopter then rolled right and collided with the ground. Examination revealed that the cyclic stick had been replaced with a military style cyclic. The owner reported that the cyclic had been cut down by removing a section of the cyclic, and the cyclic detached at the repaired joint. A review of the maintenance records did not reveal who or when the modification was performed. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_1997_NYC98LA006.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
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Related research
Matched on aircraft type or causal vocabulary (loss of control, maintenance). All research papers
- NTSB Aircraft Accident Reports 2002 · Accident report Loss of Control and Impact with Pacific Ocean — Alaska 261
Alaska Airlines Flight 261 (MD-83) Pacific Ocean, January 31, 2000 — 88 fatalities. Definitive investigation of the Alaska 261 pitch-runaway-and-loss-of-control crash.
- 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 2026 · Article (Reliability Engineering & System Safety) Understanding human error in military aviation maintenance: The role of Performance shaping factors, cognitive workload and error orientation
- 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…
- 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.
- Semantic Scholar 2024 · Article (Defence Science Journal) Modelling of Human Factors in Aviation Maintenance Using HFACS ME Human Factors Analysis and Classification System Maintenance Extension and Bayesian Network
Aircraft maintenance is a complex task involving a skilled human workforce, spare parts, and various other resources. Human factors are an inherent element of the human workforce.