Keep Your Eyes on the Hook! Underslung External Load Safety
This video was commissioned by Transport Canada and highlights key lessons for working safely around helicopters and longline loads.
Canadian Coast Guard Ground Crewman Michel Raymond’s story of an incident he was involved in is particular worth hearing.
UPDATE 7 September 2016: A worker gots caught in Australia during a helirig operation for a mining company (ATSB database entry and WA Department of Mines and Petroleum report).
As the helicopter lifted the rig, [a worker's] leg became entangled in a tag line. He was lifted some distance before the helicopter pilot became aware of the situation.
On 23 May 2016 at about 0700 Western Standard Time, a team of ground and flight crew commenced sling operations to move a drill rig and associated platform and equipment by helicopter to a new location on a salt lake at Lake Disappointment, Western Australia.
The ground team for the removal of the equipment consisted of a load master and a driller’s offsider.
The driller’s offsider involved in the operation was new to the role. For the operation, the offisider’s role included ground support and to sling equipment under the guidance of the load master. The load master was to guide the helicopter using hand signals and a two way radio to communicate with the helicopter pilot.
The pilot of an Aerospatiale Industries AS350 helicopter, registered VH-BII, worked with the ground crew to move three mats and a power pack to a new site, before returning to move the rig. The load master and offsider attached the rig to the hook under the helicopter and attached two tag lines – 6 m loop slings, to the load on separate corners. At about 1040, in readiness to lift the rig, the load master advised the pilot using hand signals that the load was attached and that they were clear and ready for the lift.
The helicopter climbed and the rig lifted a few centimetres above the ground. The load swivelled as it lifted off the ground, and pushed against a PVC pipe protruding from a bore hole. The load master and offsider stepped in closer to manoeuvre the rig clear of the pipe.
The pilot observed the ground crew then step away from the rig. As they stepped back, the offsider had inadvertently stepped into the loop of the tag line. As the helicopter lifted the rig, the tag line went taught, and the offsider’s leg was ensnared in the loop. The offsider was lifted off the ground by the leg and the helicopter began lifting the load. The load master radioed the pilot, and advised that the offsider was hanging in the loop.
The helicopter was then about 50–60 ft above the salt lake. The pilot turned the helicopter around to return to the pad and descended to about 15–20 ft above the ground. The pilot also slowed the helicopter as much as possible given the load and the tailwind, to a groundspeed of about 25 kt.
The offsider then freed their leg and was about to jump off, but the helicopter then started to climb and accelerate. The offsider therefore released the tag line and dropped about 10 m into the mud below. The offsider sustained a serious injury.
The ground crew operations company has advised the ATSB that they have taken the following safety actions:
- people carrying out slinging operations are to use more appropriate tag lines – 16 mm single strand synthetic rope
- ground crew to undergo Dogging training ["use and care of slings and strapping gear, and load movement and crane operations]
- helicopter pilot to visually confirm the load is not entangled prior to moving off
- job hazard analysis to incorporate the use of tag lines
- safe working procedures to take into account visual confirmation that the load is clear
- promotion of ‘take 5 culture’["Take 5 culture increases safety awareness by encouraging workers to 5 minutes to assess hazards and implement risk control actions."] to address hazards as they are identified
- platform scales to weigh rig items have been provided, sling line certification has been conducted and and routine condition inspections have been conducted
- UHF radios have been installed.
The air operator has advised the ATSB that they have taken the following safety actions:
- Enhanced briefing implemented for client ground crew which includes potential of entanglement and preventative measures as well as roles when there are more than one ground crew member.
- A risk profile has been completed for tag line use.
- Clients are provided with a personal protective equipment list for their personnel involved with ground operations.
ATSB Safety Message
This incident highlights the importance of conducting a thorough risk analysis prior to commencing operations. The risk assessment should clearly identify hazards and introduce measures that mitigate any associated risks. In addition, it is important to consider possible emergency scenarios and develop procedures to follow in the event of an abnormal situation developing.
Appropriate training is essential for personnel working in complex operations. In addition to individual roles and skills, training should include how team members work together to maintain and improve safety. Part of working together safely involves effective communication and a mutual understanding of phrases and signals.
The Flight Safety Foundation (FSF) run Helicopter External Load Operations for Ground Personnel training.
Also see our articles:
- What the HEC?! – Human External Cargo
- Helicopter Underslung Load: TV Transmitter
- French Skyscraper: Helicopter Underslung Load
- EC120 Underslung Load Accident 26 September 2013 – Report
- UPDATE 19 December 2016: The Tender Trap
- UPDATE 4 February 2017: Unexpected Load: AS350B3 USL / External Cargo Accident in Norway
- UPDATE 12 November 2017: Unexpected Load: B407 USL / External Cargo Accident in PNG
- UPDATE 1 December 2018: Helicopter Tail Rotor Strike from Firefighting Bucket
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