Robinson R66 N7000J

Summary

On 1 August 2021 at about 19:51 local time, a Robinson R66 registered N7000J was involved in an accident near Colusa, California, United States. 4 people were on board and 4 died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

1 August 2021 at 19:51

Classification

Accident

Location

Colusa, California, United States

Coordinates

39.2968, -122.0394

Aircraft

Robinson R66

Registration

N7000J

Category

Helicopter

Year built

2013

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Willows → Williams

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

WPR21FA300

4 people died.

The pilot’s abrupt flight control input that led to mast bumping and a subsequent in-flight breakup.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot was conducting a personal flight during daytime visual flight rules conditions with three passengers aboard. A witness who was driving on a nearby highway observed the helicopter flying on an easterly heading about 50 to 100 ft above ground level. The witness stated that the helicopter was initially straight and level but had suddenly made a sharp left turn. The witness briefly lost sight of the helicopter due to trees; when he reestablished visual contact, he observed the helicopter descend and impact terrain. Postaccident examination of the helicopter revealed no evidence of any pre-existing mechanical malfunction that would have precluded normal operation. The forward left and right control tube attachment bolts at the nonrotating swashplate were not located at the accident site or within the recovered wreckage. The flight control bolts most likely separated during the accident sequence as a result of an overstress fracture. No evidence of preexisting loosening of the attachment nuts, such as substantial thread imprints in the lug bores, was observed. This damage was consistent with the blade grips contacting the mast, commonly referred to as mast bumping, which occurs due to excessive flapping motion of rotor blades (specifically, up-and-down motion of the blade tips). It is likely that, during the flight, the pilot made an abrupt flight control input that resulted in a main rotor blade contacting the tailboom and a subsequent in-flight breakup. The reason for the pilot’s abrupt control inputs could not be determined.

Quoted verbatim from the NTSB record.