NTSB CAROL · Event
Event MIA00LA111
Aircraft involved
Probable cause & findings
The pilot's improper collective and cyclic control usage during an emergency descent, following the onset of a 1 to 1 vibration for undetermined reasons, resulting in the helicopter landing hard and rolling over.
Factual narrative
On March 17, 2000, about 1352 eastern standard time, a Hiller UH-12B, N5304V, registered to a private owner, crashed while attempting a emergency landing at Sanford Airport, Sanford, Florida, while on a Title 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The helicopter received substantial damage and the commercial-rated pilot received minor injuries. The flight originated from Sanford, Florida, a few minutes before the accident. The pilot stated he was performing practice autorotations with power recoveries. While departing into the pattern, he began to experience a severe one per revolution vibration. He was climbing through about 50 feet. He immediately lowered the collective and tried to maintain an approach to the surface away from construction workers and equipment. As he got closer to the surface the vibrations intensity increased substantially to the point where he could hardly hold onto the controls or see outside the helicopter. He attempted to raise the collective as he neared the surface and felt as if there was no response or control of the helicopter at that point. After the helicopter hit the surface and rolled a few times, he unbuckled the seat belt and got out of the helicopter. Postcrash examination of the crash site and helicopter was performed by a FAA inspector. The inspector stated the initial impact point of the helicopter was about 300 feet from the final stopping point, indicated by the two tail rotor blades lying where they had initially struck the ground and became separated from the tail rotor hub. There were skid marks from this point to the final spot where the helicopter rolled onto it's right side. There were no indications of more than one roll and no indication of a complete roll, only 90 degrees to end resting on the right side. The main rotor blades had been shattered from the impact, but the steel spar straps were intact and still attached to the rotor hub. One control paddle had been broken off at the hub from the impact. Control continuity was established for the main rotor and engine controls, but the tail rotor cables had been separated during the crash. They were still connected at the pedals and pitch change horn. No obvious mechanical defects could be detected. The "P" lead from the left magneto was hanging loose from the magneto. The threads on the "P" lead cap were not damaged and the magneto had no impact damage. A witness located in a construction area on the airport, near the crash site, stated he observed the helicopter circle overhead practicing landings west of runway 18-36. He watched the helicopter land and then takeoff again. During takeoff and climb the helicopter sound changed and he watched the helicopter descend from about 200 feet, in level flight but coming down fast. The helicopter hit the ground and flipped over. While climbing after takeoff, the pilot stated he experienced a 1 to 1 vibration. He lowered the collective and initiated an approach the surface. The vibration got worse and as he approached the surface and raised the collective the helicopter felt like there was no response from the controls. The helicopter hit hard and rolled onto it's side. Post crash examination of the helicopter by an FAA inspector showed no obvious mechanical defects in the rotors or flight control systems. The left engine magneto 'P' lead was found loose, rendering the magneto inoperative. The threads on the 'P' lead had no damage and the magneto was not damaged from impact. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_2000_MIA00LA111.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 (icing). Sourced from NASA NTRS, NTSB Safety Studies, FAA CAMI, AOPA Air Safety Institute, Embry-Riddle Scholarly Commons, arXiv, and the Semantic Scholar academic graph.
- NASA NTRS 2026 · Contractor Report (CR)
Icing Physics Studies Using the 3D SIDRM Test Article: 2023 Icing Tests Analysis
In-flight icing is an important safety issue and is a factor that affects aircraft design and performance. Newer regulations are driving a need for improvements in airframe and engine icing simulation…
- arXiv 2025 · arXiv preprint
Multi-Agent Deep Reinforcement Learning for UAV-Assisted 5G Network Slicing: A Comparative Study of MAPPO, MADDPG, and MADQN
The growing demand for robust, scalable wireless networks in the 5G-and-beyond era has led to the deployment of Unmanned Aerial Vehicles (UAVs) as mobile base stations to enhance coverage in dense urb…
- Embry-Riddle Scholarly Commons 2025 · Journal article (JAAER)
A Mathematical Model on the Temporal Dynamics of Aviation Competitive Pricing
This study investigates the competitive dynamics of airport pricing using U.S. airport data to validate the findings. It employs linear and nonlinear ordinary differential equation models to analyze t…
- NASA NTRS 2025 · Presentation
NASA Icing Update – March 2025
This NASA Icing Update was prepared for presentation to the SAE International AC-9C Inflight Icing Technology Committee. This update includes the following topics: planned Rotational Icing Scaling tes…
- arXiv 2024 · arXiv preprint
An energy-stable phase-field model for droplet icing simulations
A phase-field model for three-phase flows is established by combining the Navier-Stokes (NS) and the energy equations, with the Allen-Cahn (AC) and Cahn-Hilliard (CH) equations and is demonstrated ana…
- NASA NTRS 2024 · Presentation
NASA Icing Update – Oct 2024
This presentation provides a status update on select NASA icing research activities for the SAE AC-9C Icing Technical Committee Meeting on Oct 21, 2024.
Browse the full corpus — academia portal ↗