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Atlas / NTSB / WPR22LA291

NTSB CAROL · Event

Event WPR22LA291

2022-08-03 Chino, California, United States Airport · KCNO None 1 aircraft Status: Completed

Registry · N833SB

FAA Aircraft Registry record.

Make / Model

AIRBUS HELICOPTERS INC AS350B3

Year of manufacture

2017 · 5 years old at event

TCDS

H9EU · AIRBUS HELICOPTERS

Engine

SAFRAN ARRIEL 2D (952 hp)

Seats / Engines

7 seats · 1 engine

Last airworthiness date

20171122

ADS-B equipped

Yes — Mode-S AB6511

Registrant of record

SAN BERNARDINO COUNTY SHERIFFS DEPT

Source: FAA Aircraft Registry (releasable master file).

Aircraft involved

Probable cause & findings

The subsequent delamination of the main rotor blades as a result of an unidentified main rotor blade impact with vegetation during a previous flight by another pilot.

Factual narrative

The pilot of the helicopter reported that, he noticed a slight bounce during flight that felt like an out of balance main rotor blade. The pilot diverted to a nearby airport as the helicopter began to shake aggressively with a whipping noise hear. During the approach, the shaking worsened, and the pilot elected to perform a run-on landing at the airport. During the following inspection, it was revealed that the main rotor blades were substantially damaged due to delamination. There was also evidence of impact marks near the tip blades that was consistent with contact with vegetation. The operator reported that, 2 days before the accident flight, the blades may have impacted vegetation during an “off-site” landing. According to that pilot, while the front left seat passenger was exiting the helicopter, she inadvertently sat down on the left side collective, pushing it to the full-down position. The helicopter rolled backwards suddenly, resulting in the heels of the skids to contact the ground. The pilot corrected the helicopter’s attitude and checked that the collective’s movement was normal. The helicopter was shut down shortly after and tail and main rotor blades were inspected by the pilot who reported that he didn’t see any evidence of impact at that time. Maintenance personnel inspected the helicopter following the flight and no statements or writeup was found during the investigation. The three pilots that flew the helicopter after the unidentified impact all reported that they felt a slight bounce in the helicopter at speeds of approximately 115 knots and thought that it was a slight out of balance/track rotor and was not that significant. 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).

  • Aircraft-Aircraft propeller/rotor-Main rotor system-Main rotor blade system-Damaged/degraded
  • Environmental issues-Physical environment-Object/animal/substance-Tree(s)-Effect on equipment

Verbatim from NTSB's published report. Source file NTSB_2022_WPR22LA291.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.

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.

Browse the full corpus — academia portal ↗