Robinson R22 BETA N8313Z

Summary

On 19 August 2000 at about 00:55 local time, a Robinson R22 BETA registered N8313Z was involved in an accident near Watsonville, California, United States. 2 people were on board and 2 died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

19 August 2000 at 00:55

Classification

Accident

Location

Watsonville, California, United States

Coordinates

36.8956, -121.7942

Aircraft

Robinson R22 BETA

Registration

N8313Z

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Watsonville → Unknown

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

LAX00FA306

2 people died.

The divergence of the main rotor from its normal plane of rotation for an undetermined reason, which resulted in mast bumping and rotor contact with the fuselage.

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

Read the full NTSB narrative

The flight instructor was cruising or maneuvering the helicopter during an introductory flight with a new student. Witnesses in the area reported observing the helicopter in what appeared to be normal flight, heard a loud bang, and then saw the helicopter abruptly pitch nose down while the main rotor blades separated from the helicopter. One of the witnesses observed the helicopter turn and climb moments before the accident sequence initiated; two of the witnesses reported that just prior to the accident the helicopter was flying in level cruise flight. At the time of the accident, the sky was clear, the visibility was at least 10 miles, a light breeze existed, and no other aircraft were flying in the immediate area. The on-scene examination of the accident site revealed Plexiglas fragments and left door components about 400 feet from where the main wreckage fell into an open dirt field. Additional items, including sunglasses, a left skid tube-mounted component and the main rotor blade assembly, were found 140 to 330 feet from the main wreckage. An examination of the rotor hub revealed the teetering stops were cracked and both of the rotor blade spindles had broken their respective (droop stop) tusks. The physical evidence indicates the main rotor diverged from its normal plane of rotation, resulting in mast bumping, main rotor blade contact with the fuselage, and separation of the main rotor assembly. No evidence of any preimpact mechanical malfunction was found with the helicopter. The initiating event that produced the main rotor divergence could not be determined.

Quoted verbatim from the NTSB record.