NTSB CAROL · Event
Event WPR16LA156
Aircraft involved
Probable cause & findings
The flight instructor’s delayed remedial action to address a low rotor rpm condition, which resulted in an excessive descent rate and a subsequent hard landing.
Factual narrative
On August 2, 2016, about 1027 mountain standard time (MST), a Robinson R22 helicopter, N22UH, landed hard at Ernest A Love Field Airport, Prescott, Arizona. The certificated flight instructor and student pilot received minor injuries. The helicopter sustained substantial damage to the fuselage and the tail boom. The helicopter was registered to Alba Leasing Services and operated by Universal Helicopters under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91 as an instructional flight. Visual meteorological conditions prevailed, and no flight plan was filed. The local flight departed Prescott, Arizona, about 0950. The student pilot and the flight instructor were practicing straight in autorotations. During the glide, with the student pilot at the controls, about 400 feet above ground level, the flight instructor noticed a fast rate of decent and a decay in rotor RPM. The flight instructor stated to the student that he had the controls and started applying collective and throttle control to recover RPM. The instructor felt the collective go up and stated again to the student that he had the controls. The flight instructor was unable to arrest the decent or recover RPM prior to the hard landing. During touchdown, the landing skids collapsed, the main rotor blades connected with and severed the tail boom. The helicopter came to rest on its left side. The flight instructor reported no pre-impact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation. The flight instructor and student pilot were practicing straight-in autorotations in the helicopter. During the autorotative descent, about 400 ft above ground level with the student at the controls, the instructor noticed a high rate of descent and a decay in main rotor rpm. The instructor told the student that he had the controls and started applying collective and throttle to recover rpm. He felt the collective go up and again told the student that he had the controls. The instructor was unable to arrest the descent before the helicopter landed hard and rolled over. The instructor reported that there were no pre-impact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation. He further stated that the accident could have been prevented if he had stayed ahead of his student and the helicopter. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12
NTSB Findings
Hierarchical cause / factor breakdown from the FAA bulk avdata database. Each finding tagged C (Cause) or F (Factor).
- C Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Descent/approach/glide path-Not attained/maintained - C
- C Personnel issues-Task performance-Use of equip/info-Aircraft control-Student/instructed pilot - C
- C Personnel issues-Psychological-Attention/monitoring-Monitoring other person-Instructor/check pilot - C
- C Personnel issues-Action/decision-Action-Delayed action-Instructor/check pilot - C
Verbatim from NTSB's published report. Source file
NTSB_2016_WPR16LA156.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.
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- arXiv 2025 · arXiv preprint
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- Embry-Riddle Scholarly Commons 2025 · Journal article (JAAER)
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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
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Browse the full corpus — academia portal ↗