Robinson R22 BETA N827SH

Summary

On 27 August 2021 at about 13:00 local time, a Robinson R22 BETA registered N827SH, operated by 1 Acadiana Helicopters Company LLC, was involved in an accident near Arnaudville, Louisiana, United States. One person was on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

27 August 2021 at 13:00

Classification

Accident

Location

Arnaudville, Louisiana, United States

Coordinates

30.3953, -91.9346

Aircraft

Robinson R22 BETA

Registration

N827SH

Category

Helicopter

Year built

2005

Engines

1

Operator

1 Acadiana Helicopters Company LLC

Operating rule

Part 91: General Aviation

Purpose of flight

Positioning

Phase of flight

Not recorded

Route

New Iberia → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN21LA389

1 person had minor injuries.

The loss of tail rotor drive due to a fatigue failure of the tail rotor gearbox output shaft, which resulted in a loss of control during landing.

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

Read the full NTSB narrative

While attempting to land at a staging location for a planned aerial application flight, the helicopter began to rotate to the right. The pilot was unable to regain control. The helicopter skids impacted a dirt field, and the helicopter rolled over onto its right side. The helicopter sustained substantial damage to its main rotor blades and fuselage. Disassembly of the helicopter for recovery revealed the tail rotor output shaft was fractured into two pieces. Examination of the output shaft revealed the fracture occurred between the mating tapered roller bearing and the bevel gear. The bevel gear side surface displayed progressive crack arrest marks consistent with fatigue cracking. Due to smear damage on the other fracture, it could not be determined if the fatigue cracking was the result of unidirectional bending fatigue (one origin) or reverse bending fatigue (two origins). The tail rotor output shaft function is to drive the tail rotor blades. A failed tail rotor output shaft would result in the loss of drive to the tail rotor blades, which in turn would cause a loss of tail rotor thrust to counter main rotor torque and loss of yaw control.

Quoted verbatim from the NTSB record.