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Accidents · NTSB WPR16LA075 · Final report

Robinson Helicopter CO R66 accident near Torrance, California, February 23, 2016

On February 23, 2016 at about 7:45 pm local time, a 2009 Robinson Helicopter CO R66, registered N266RH, was substantially damaged in an accident during maneuvering near Torrance, California (Zamperini Field). It was a flight test under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).

The NTSB's probable cause their words, unchanged

A vibration of the helicopter, which resulted in an autorotation to soft terrain and subsequent impact of the tail boom with the main rotor. The reason for the vibration could not be determined because postaccident examination revealed no malfunctions or anomalies that would have precluded normal operation.

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

What the record shows

Date
February 23, 2016 · about 7:45 pm local time
Place
Torrance, California · Zamperini Field · map
Type
Accident
Injuries
No one was hurt; 1 person was on board or involved.
Weather
visual conditions (good weather)
Aircraft
Robinson Helicopter CO R66 NO SERIES, built 2009
Registration
N266RH · registry record · serial 0002
Damage
Substantial damage
Flight
Flight test · general aviation rules (Part 91)

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

The commercial pilot was performing company flight testing in the helicopter. After performing an air taxi and a hovering autorotation, the pilot conducted a simulated maximum performance takeoff. About 200 ft above ground level, the pilot heard a noise and felt a momentary helicopter vibration. He subsequently performed a precautionary autorotation to a grass area on airport property. The pilot stated that the helicopter had forward speed during the landing and that the grass was soft; as a result, the helicopter entered a fore-aft rocking motion after touchdown, and the main rotor contacted the tail boom, resulting in substantial damage. Postaccident review of data from the engine monitoring unit revealed no anomalies, and an examination of the helicopter revealed no evidence of  mechanical malfunctions or failures that would have precluded normal operation; therefore, the reason for the noise and vibration could not be determined.

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. Miscellaneous/other during maneuvering defining event
  2. Autorotation Miscellaneous/other
  3. Abrupt maneuver during landing (flare/touchdown)

The NTSB's findings

  • factor Not determined › Not determined › (general) › (general) › Unknown/Not determined
  • Environmental issues › Physical environment › Terrain › Wet/muddy terrain › Not specified

Pilot

  • Certificate: flight instructor, commercial pilot
  • Ratings: single-engine sea; instructor: airplane single-engine; instructor: helicopter; instructor: instrument helicopter; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
  • Flight time: 1,750 hours in all; 200 in this make and model; 30 in the last 90 days; 15 in the last 30 days; 1,650 as pilot in command
  • Last flight review: April 23, 2014
  • Medical certificate: Class 2 (with waivers/limitations)
  • Seat: rgt
  • Injury: no injuries

The aircraft

  • Airframe total time: 400.0 hours
  • Last inspection: annual inspection, October 15, 2015
  • Maximum gross weight: 2,700 lb
  • Seats: 5
  • Landing gear: fixed
  • Engine: Rolls-Royce 250-C300/A1 (turboshaft); 363 hours total
  • Operator: Robinson Helicopter CO

The flight

  • Departed from: TOA Torrance CA at 7:30 pm
  • Destination: TOA Torrance CA
  • Flight plan: none

Weather at the time

  • Light: daylight
  • Visibility: 10 statute miles
  • Sky: scat at 20,000 ft
  • Temperature: 84°F (29°C), dew point 36°F (2°C)
  • Altimeter: 30.01 inHg
  • Observation at 6:53 pm from KTOA

Injuries

FatalSeriousMinorNone
Flight crew1

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

The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.

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.