NTSB CAROL · Event
Event CEN21LA431
Registry · N632SD
FAA Aircraft Registry record.
Make / Model
EUROCOPTER AS 350 B2
Year of manufacture
2002 · 19 years old at event
TCDS
H9EU · AIRBUS HELICOPTERS
Engine
TURBOMECA ARRIEL 1D1 (712 hp)
Seats / Engines
6 seats · 1 engine
Last airworthiness date
20020617
ADS-B equipped
Yes — Mode-S A846BE
Registrant of record
COUNTY OF OAKLAND
Source: FAA Aircraft Registry (releasable master file).
Aircraft involved
Probable cause & findings
The flight instructor’s failure to reposition the fuel control to the flight detent during a practice autorotation, which resulted in insufficient engine power to arrest the helicopter’s decent and a hard landing.
Factual narrative
The flight instructor reported that he intended to demonstrate to the student pilot a 180° autorotation with a power recovery near the ground. He planned to transition the helicopter into to a hover about 5 to 10 ft above ground level at the end of the maneuver. The instructor initially set the engine fuel control to the idle detent to simulate an engine failure and then entered an autorotation. As the autorotation progressed, the flight instructor repositioned the engine fuel control, but he failed to ensure that it had been placed into the flight detent. Without sufficient engine power at the end of the maneuver, the helicopter continued to descend with a low rotor speed, landed hard, and slid to a stop on the runway. Then the helicopter violently rocked side to side before the main rotor stopped rotating. During the accident sequence, the helicopter sustained substantial damage to a main rotor Starflex arm and the tail rotor driveshaft. Both the flight instructor and his student reported there were no mechanical malfunctions or failures of the helicopter that would have precluded normal operation. 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).
- — Personnel issues-Task performance-Use of equip/info-Use of equip/system-Pilot
Verbatim from NTSB's published report. Source file
NTSB_2021_CEN21LA431.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 (engine failure). Sourced from NASA NTRS, NTSB Safety Studies, FAA CAMI, AOPA Air Safety Institute, Embry-Riddle Scholarly Commons, arXiv, and the Semantic Scholar academic graph.
- arXiv 2022 · arXiv preprint
Multi-level Adaptation for Automatic Landing with Engine Failure under Turbulent Weather
This paper addresses efficient feasibility evaluation of possible emergency landing sites, online navigation, and path following for automatic landing under engine-out failure subject to turbulent wea…
- NASA NTRS 2019 · Conference Paper
Simulation of Liquid Rocket Engine Failure Propagation Using Self-Evolving Scenarios
Traditional probabilistic risk assessment approaches often require failure scenarios to be explicitly defined through event sequences that are then quantified as part of the integrated analysis.
- NASA NTRS 2019 · Conference Paper
Rocket engine failure detection using system identification techiques
The theoretical foundation and application of two univariate failure detection algorithms to Space Shuttle Main Engine (SSME) test firing data is presented.
- NASA NTRS 2019 · Conference Paper
Rocket engine failure detection using system identification techniques
The theoretical foundation and application of two univariate failure detection algorithms to Space Shuttle Main Engine (SSME) test firing data is presented.
- NASA NTRS 2019 · Technical Memorandum (TM)
A simulator investigation of engine failure compensation for powered-lift STOL aircraft
A piloted simulator investigation of various engine failure compensation concepts for powered-lift STOL aircraft was carried out at the Ames Research Center.
- Semantic Scholar 2019 · Article (AIAA Scitech 2019 Forum)
Impact of Engine Failure Constraints on the Initial Sizing of Hybrid-Electric GA Aircraft
Potential advantages of hybrid-electric aircraft are fuel savings, lower emissions, and reduced noise. Since these aircraft generally apply multiple power sources, they can also be designed to sustain…
Browse the full corpus — academia portal ↗