Aviation safety investigations & reports

Aerospatiale AS350B, VH-AFO, Grass Tree Hill (11 km NW of Cambridge) TAS, 29 July 1988

Investigation number:
Status: Completed
Investigation completed


Download Final Report
[Download  PDF: 23KB]

The pilot and the helicopter were involved in a training exercise for trainee fireman. The task was to teach safety around helicopters, especially relating to fire fighting activities. The State Fire Commission provided new sling equipment, purchased from a ship chandler. Experienced fire fighting personnel had prepared several sling loads in advance for the pilot. The strop chosen to lift the 500kg water bladder was 20 metres long. The purpose of the long strop was to enable the helicopter to lower the water bladder to firemen working in low scrub. The strop had been assembled by passing each end of the rope around a metal eyelet and whipping it because the polyester rope was not suitable for splicing. Visually the whipped ends looked satisfactory.

The helicopter lifted the load to about 150 feet above the ground and was accelerating through about 20 knots when the pilot heard a loud bang, felt a vibration through the airframe and realised that the load had detached from the helicopter. He made a precautionary landing nearby. The rope of the strop had slipped through the whipped section at the eyelet where it attached to the water bladder with a shackle. The rope had recoiled, damaged one of the three main rotor blades, ripped the right hand horizontal stabilizer and wrapped around the tail boom.

The known safe working load limits for the individual items comprising the strop were more than adequate for the intended sling loads. The new strop had never been proof tested; nor was there any indication that the helicopter company or the Fire Commission had instructed the manufacturer to proof test the strops.

Download Final Report
[Download  PDF: 23KB]
General details
Date: 29 July 1988   Investigation status: Completed  
Time: 1113    
Location: Grass Tree Hill (11 km NW of Cambridge)    
State: Tasmania   Occurrence type: Miscellaneous - Other  
Release date: 21 February 1989   Occurrence category: Accident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer Aerospatiale Industries  
Aircraft model AS350  
Aircraft registration VH-AFO  
Serial number 1105  
Type of operation Aerial Work  
Sector Helicopter  
Damage to aircraft Substantial  
Departure point Grass Tree Hill TAS  
Departure time 1113  
Destination Grass Tree Hill TAS