Investigation number
199702320
Occurrence date
Location
11 km E Mackay, Aero
State
Queensland
Report release date
Report status
Final
Investigation type
Occurrence Investigation
Investigation status
Completed
Occurrence class
Accident
Highest injury level
None

The MV " Karoo ", a large bulk carrier, was at anchor 11 km off Mackay, facing approximately 090 degrees M. The wind was from the south-east at about 25 kts. The helicopter had been chartered to transfer two members of the vessel's crew from shore to the ship. After an uneventful flight, the pilot landed the helicopter on the port side of cargo hatch number seven which measured 20.0 m by 14.45 m and had a smooth painted steel surface. The cargo hatch peaked in the centre and sloped down 0.85 degrees to both the port and starboard sides of the ship. The pilot positioned the helicopter so that the tail rotor protruded over the edge of the hatch on the port side. In this position, the helicopter was under the influence of a crosswind from the left front quarter. The pilot stated that he reduced the engine power to ground idle, friction-locked the cyclic and collective controls, and locked the anti-torque pedals. He then exited the cabin and walked to the right side of the helicopter to supervise the disembarkation of the passengers and to remove their luggage.

After the passengers had stepped from the helicopter, it weather-cocked about 30 degrees to the left and commenced to slide slowly backwards towards the edge of the cargo hatch. The pilot ran back to the left side of the helicopter and attempted to unlock the anti-torque pedals prior to climbing aboard. The front of the helicopter then pitched up with the pilot partly on board, then fell 3 m onto the main deck and landed inverted beside raised piping which ran along the length of the deck. The pilot fell between the hatch and the piping and was saved from flailing rotor blades by two steel posts supporting the pipe system. The engine continued to operate for 30 to 60 seconds after the impact.

In accordance with standard procedures, the vessel's fire-fighting crew was on duty for the arrival of the helicopter. The crew sprayed the wreckage with foam and salt water as a precaution against fire.

Examination at the accident site revealed scratch marks that indicated that the left skid landing gear had dug into the painted hatch surface. The rear portion of the left skid broke in overload as the helicopter pitched up. Examination of the wreckage confirmed that the pilot had locked the controls and that the throttle control was positioned in the ground-idle detent.

Additional information

An Australian Maritime Safety Authority (AMSA) booklet "Ship - Helicopter Transfers, Australian Code of Safe Practice", states that the helicopter landing site (HLS) should have a non-slip surface. On the MV "Karoo", the cargo hatch designated as the HLS was painted, smooth steel plate. It did not have a non-slip surface.

Civil Aviation Orders (CAO) generally required that the pilot remain at the controls during engine operation. However, CAO 95.7.7 allowed an exemption if the pilot considered that passenger safety, or the safety of people in the vicinity, may be compromised, provided that the controls were locked, and the pilot remained in the immediate vicinity. The pilot in this instance regarded the passengers as potentially at risk due to their unfamiliarity with the helicopter operations and their inability to understand English. As an additional safety consideration, he had positioned the tail rotor beyond the edge of the cargo hatch.

The crosswind landing technique required the pilot to counter the total effect of wind on the helicopter by positioning the cyclic control so that the main rotor thrust was biased into wind, towards the 10-o'clock position, to counteract the aerodynamic drag. When the pilot locked the controls, the cyclic control was locked in the position that was selected for landing, maintaining the main rotor bias.

Aircraft Details
Manufacturer
Hughes Helicopters
Model
369
Registration
VH-WHP
Serial number
990578D
Operation type
Charter
Sector
Helicopter
Departure point
Mackay, QLD
Departure time
1620 hours EST
Destination
MV "Karoo", 11 km E Mackay, QLD
Damage
Substantial