Aviation safety investigations & reports

Main rotor blade skin debonding - Robinson helicopter R22 Beta, VH-HZB, 135 km NE Alice Springs, NT on 29 December 2008

Investigation number:
Status: Completed
Investigation completed


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While conducting a survey flight at Ambalindum Station (approximately 135 km north-east of Alice Springs, NT), the pilot of a Robinson R22 Beta helicopter, registered VH-HZB, noticed severe vibration of the main rotor assembly and cyclic controls. The pilot landed the helicopter immediately, and a subsequent inspection revealed that a length of aerofoil skin had peeled back from the leading edge on the underside of one of the main rotor blades.

A review of the current information surrounding Robinson helicopter blade debonds found a number of previous incidents involving a similar failure mechanism. Additionally, the issue of main rotor debond had been addressed by a number of airworthiness directives (ADs) issued by the Civil Aviation Safety Authority (CASA) and the Federal Aviation Authority (FAA), along with a number of safety alerts and service letters issued by the manufacturer.

Debonding of the main rotor blade skin was considered to have been influenced by extensive surface erosion observed around the leading edges of the blade. Additionally, the investigation found no evidence to suggest that the actions contained within the current CASA Airworthiness Directive addressing blade debonding issues (AD/R22/54) had been integrated into the helicopter's maintenance routine. The logbooks and maintenance release documents for the helicopter have since been updated to include reference to AD/R22/54 Amdt 3.

Download Final Report
[Download  PDF: 2.57MB]
General details
Date: 29 December 2008   Investigation status: Completed  
Time: 1000 CST   Investigation level: Systemic - click for an explanation of investigation levels  
Location   (show map): Ambalindum Station    
State: Northern Territory   Occurrence type: Propeller/rotor malfunction  
Release date: 23 December 2009   Occurrence category: Accident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer Robinson Helicopter Co  
Aircraft model R22  
Aircraft registration VH-HZB  
Serial number 880  
Type of operation Private  
Sector Helicopter  
Damage to aircraft Substantial  
Departure point Ambalindum Station, NT  
Destination Ambalindum Station, NT  
Last update 03 April 2020