Aviation safety investigations & reports

Sikorsky S58E/T Helicopter, VH-UHV, Darwin Harbour, NT, 25 March 1972

Investigation number:
Status: Completed
Investigation completed


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The helicopter was substantially damaged when it was ditched in the harbour at Darwin, Northern Territory as a result of the tail rotor and the tail rotor gearbox separating from the aircraft in flight. The flight from the oil rig, positioned 227 degrees (M), 137 miles from Darwin, was uneventful until the helicopter was crossing Darwin Harbour some seven miles from the airport at a height of 1,000 feet and at a speed of 100 knots. At this point the pilot noticed a slight vibration, lasting about five seconds, which he was unable to identify. The vibration increased in intensity and there were three distinct thumps after which the helicopter pitched violently nose down and yawed to the right. The pilot lowered the collective pitch and brought the helicopter under control. Although the vibration was less severe he was unable to read any instruments. He transmitted a distress message which was received and acknowledged by Darwin Tower. The pilot then attempted to apply a small amount of collective pitch but the vibration became violent. He continued with the auto rotation, armed the flotation gear, closed the throttles to the flight idle position and the aircraft landed smoothly on the water with some right yaw. The helicopter turned clockwise in the water through about 240 degrees before it rolled onto its port side and the main rotors struck the water. Both of the wheel-mounted flotation units inflated but the one mounted on the left wheel was breached, probably during inflation. The pilot, after vacating the aircraft, assisted the passengers and all were quickly rescued by nearby boats. The aircraft remained partially submerged, resting on a sand bar, and was later recovered.
Download Final Report
[Download  PDF: 252KB]
General details
Date: 25 March 1972   Investigation status: Completed  
Time: 1330 CST    
Location: Darwin Harbour    
State: Northern Territory    
Release date: 20 June 1972   Occurrence category: Accident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer Sikorsky Aircraft  
Aircraft model S-58  
Aircraft registration VH-UHV  
Type of operation Charter  
Sector Helicopter  
Damage to aircraft Substantial  
Departure point Oil Rig 137 miles from Darwin  
Destination Darwin  
Last update 01 April 2011