Aviation safety investigations & reports

Robinson Helicopter Co R44, VH-AIC

Investigation number:
200300316
Status: Completed
Investigation completed

Summary

The Robinson R44 helicopter departed from Shipwreck Bay, QLD at about 1245 Eastern Standard Time on the final leg of a charter flight to Mareeba aerodrome. The pilot intended to track directly to Mareeba aerodrome under the Visual Flight Rules, with an expected enroute flight time of about 45 minutes. The pilot did not submit a flight plan to Airservices Australia, nor was a flight plan required, but the company retained a flight notification form for search and rescue purposes.

At about 1 NM to the south of Mareeba township, at a cruise altitude of 1,000 ft and an indicated airspeed of about 95 kts, the pilot heard an unusual noise associated with the main rotor blades. The pilot reported that the noise sounded as though a potato chip packet had been caught in the blades and a violent vibration occurred in conjunction with the unusual noise.

The pilot was unable to identify or read the aircraft instruments because of the vibration and was unable to adequately control main rotor RPM after the onset of that vibration.

The violent vibration necessitated a landing. The pilot entered autorotation and selected a paddock for the forced landing. He reported that the helicopter was difficult to control during the descent. In particular, he was unable to turn the helicopter with left and right cyclic inputs. In particular, while cyclic inputs altered the attitude of the helicopter left and right it would not turn in the selected direction. The pilot also reported that it was difficult to control main rotor RPM during the autorotative descent and he relied upon the low rotor RPM horn and light as an indication of rotor RPM. The horn and light activated intermittently during the descent.

During the descent, the helicopter struck powerlines and was substantially damaged. The pilot reported that he was unable to avoid the powerlines because of the ineffective cyclic inputs. The pilot and passenger, the only occupants, suffered minor injuries.

A report from the accident site indicated significant main rotor blade skin disbonding 60 mm from the tip and extending 1070 mm inboard on one blade and the beginning of skin disbonding on the other blade. The ATSB conducted a preliminary investigation and it was apparent that the problem was a continuing airworthiness matter. ATSB released the main rotor blades to the Civil Aviation Safety Authority (CASA) for further examination as part of an airworthiness investigation.

Safety Action

CASA subsequently issued Airworthiness Directive AD/R44/18 - Main Rotor Blades (Robinson R44 Series Helicopters) effective 3 March 2003. That AD directed operators of Robinson R44 Series helicopters to visually inspect and test main rotor blades' upper and lower skin-to-spar seams for evidence of disbonding of the laminate structure. Any blades that showed evidence of disbonding were to be removed from service. The AD requires the carriage of the AD on board the helicopter and the inspections in accordance with the AD `immediately before further flight' from 3 March 2003 `and thereafter at each daily inspection'.

General details
Date: 12 February 2003   Investigation status: Completed  
Time: 1330 hours EST    
Location   (show map): 4 km NNE Mareeba, Aero.    
State: Queensland    
Release date: 12 March 2003   Occurrence category: Accident  
Report status: Final   Highest injury level: Minor  

Aircraft details

Aircraft details
Aircraft manufacturer Robinson Helicopter Co  
Aircraft model R44  
Aircraft registration VH-AIC  
Serial number 0063  
Type of operation Charter  
Sector Helicopter  
Damage to aircraft Substantial  
Departure point Shipwreck Bay, QLD  
Departure time 1245 hours EST  
Destination Mareeba, QLD  
Crew details
Role Class of licence Hours on type Hours total
Pilot-in-Command Commercial 1902 2146
 
Injuries
  Crew Passenger Ground Total
Minor: 1 1 0 2
Total: 1 1 0 2
Last update 13 May 2014