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Accidents · NTSB WPR22LA291 · Final report

Airbus Helicopters INC AS350B3 accident near Chino, California, August 4, 2022

On August 4, 2022 at about 1:45 am local time, a 2017 Airbus Helicopters INC AS350B3, registered N833SB, was substantially damaged in an accident during enroute near Chino, California (N/A airport). It was a public-use flight under public-use (government) rules. No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).

The NTSB's probable cause their words, unchanged

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.

Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.

What the record shows

Date
August 4, 2022 · about 1:45 am local time
Place
Chino, California · N/A · map
Type
Accident
Injuries
No one was hurt; 2 people were on board or involved.
Weather
visual conditions (good weather)
Aircraft
Airbus Helicopters INC AS350B3, built 2017
Registration
N833SB · registry record · serial 8435
Damage
Substantial damage
Flight
Public-use flight · public-use (government) rules

The NTSB's narrative final · quoted from the NTSB record

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.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.

The factual record from the NTSB's investigation tables, in plain English

What happened, in order

  1. Sys/Comp malf/fail (non-power) during enroute defining event
  2. Emergency descent initiated during enroute

The NTSB's findings

  • 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

Pilot

  • Certificate: flight instructor, commercial pilot
  • Ratings: instructor: helicopter; rotorcraft: helicopter
  • Flight time: 3,822 hours in all; 3,400 in this make and model; 136 in the last 90 days; 45 in the last 30 days; 3,740 as pilot in command; 118 on instruments
  • Last flight review: February 12, 2021
  • Medical certificate: Class 2 (without waivers/limitations)
  • Seat: rgt
  • Injury: no injuries

Other crew

  • Seat: left
  • Injury: no injuries

The aircraft

  • Airframe total time: 2,054 hours
  • Last inspection: 100-hour inspection, July 22, 2022; 54 hours since
  • Maximum gross weight: 5,221 lb
  • Seats: 7
  • Landing gear: fixed
  • Engine: Safran Arriel 2D (turboshaft); 735 hours total
  • Operator: San Bernardino County Sheriffs Dept

The flight

  • Departed from: SBD San Bernardino CA at 1:09 am
  • Flight plan: VFR
  • A second pilot was aboard

Weather at the time

  • Light: daylight
  • Sky: clear
  • Temperature: 0°F (-18°C), dew point 0°F (-18°C)
  • Observation at 5:53 pm from CNO

Injuries

FatalSeriousMinorNone
Flight crew2

Documents from the investigation the NTSB's docket: the evidence folder behind the report

6 documents, released by the NTSB on December 8, 2022. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.

The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.

Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.