Types of Swimmer Deployments in Heavy Seas and Surf – Pros and Cons 

Each deployment option has benefits and drawbacks. Selection of the deployment is highly situationally dependent. Below is a list of pros and cons to improve crew coordination and selection of the optimal deployment provided the conditions and circumstances: 

1. Sling/harness/free fall (“indirect” deployments – swimmer disconnects from the hoist hook):  

• Pros –   
  • The swimmer can free swim in the waves unencumbered by the hook and cable. 
  • The flight mechanic does not have to manage cable and helicopter position throughout the entire evolution. 
  • The swimmer can make verbal contact with the survivor and approach deliberately, assessing the situation while providing assurance and direction.  
  • The swimmer can assess the survivor’s condition, the environment, and the situation then call for the appropriate recovery. 
  • A basket is a recovery option. If there are multiple survivors in the water, the swimmer can stay in the water between survivor recoveries.  
• Cons – 
  • Getting the device or hook to the swimmer and survivor for recovery may be difficult, slow, or arduous.  
  • The swimmer is no longer connected to the aircraft. As such, the crew must get the hook or device back to the swimmer. If something impedes the ability of the swimmer to function at a high level (e.g., injury), it may be impossible to recover them. 

2. Harness (specific):

• Pros –  
  • Situational awareness is high. The swimmer can be lowered to just above the wave crests. Even if there is a spin where their back is to the waves, swimmers can twist to keep good situational awareness of approaching waves.  
  • It is easy for the swimmer to provide clear hand signals to the flight mechanic to time deployments appropriately. 
• Cons –  
  • Disconnecting from the hook requires the swimmer to be completely in the water with cable slack. It can take time to get off the hook. 

3. Sling (specific):  

• Pros –  
  • Because the swimmer is not on a hook, they can time their own deployment by sliding out of the sling anytime on the backside of a wave even if they are not yet in the water. Conversely, if the swimmer is on the hook they must be placed in the water with appropriate cable slack to open the hook and disconnect. 
  • If the swimmer can see the approaching waves, they can time their deployment perfectly – just after the crest to the backside of the wave. 
• Cons –   
  • If the swimmer spins and is facing the wrong direction, it can be difficult to impossible to see approaching wave action. 
  • Due to the ergonomics of the sling restricting arm movement, it is difficult to provide clear hand signals to the flight mechanic to ensure appropriate altitude above the wave crests for deployment. 
  • Once the swimmer is below the cabin door, it is more difficult to abort the deployment compared to a harness or direct deployment (swimmer stays on the hook). 

4. Free fall (specific):  

• Pros –  
  • The free fall allows the swimmer the opportunity to deploy when the hoist is inoperable (e.g., rare instance that a survivor is in the water in need of timely aid – the swimmer can enter the water and keep the survivor from drowning while another rescue asset arrives on scene or while the crew rigs the secondary recovery device (ATLAS)). 
  • The swimmer controls the timing of the deployment and, if performed well, can result in an ideal deployment just after the crest on the backside of the wave.  
• Cons –  
  • The helicopter is in close vicinity to large waves varying in height.  
  • After the “deploy swimmer” call the helicopter crew has to guess/estimate altitude above the crest.  
  • Waves can “A” frame, or a larger set stands up, and can rapidly become too close to the helicopter.  
  • If the helicopter is too high (e.g., climbs to avoid a wave) and/or the swimmer times the free fall wrong (e.g., jumps into a trough), the deployment can be far above the maximum of 15’.  

5. Direct Deployment (swimmer remains connected to the hoist hook):  

• Pros –  
  • The swimmer remains attached to the helicopter. So, if something impedes the ability of the swimmer to function at a high level (e.g., injury), the crew may still be able to recover them.  
  • The direct deployment is efficient because the hook or device does not have to be returned to the swimmer.  
  • A physical grip can allow the helicopter crew to quickly extract the survivor and swimmer from a dangerous situation and reposition them to a less dynamic area for recovery. 
• Cons – 
  • Cable management can be difficult. The helicopter crew must maintain the appropriate energy management (wave energy → RS/survivor → hoist drum) but remain close enough to affect a rapid recovery without too much cable in the water, risking entanglement, while also avoiding the exposure zone. The exposure zone is the point in the recovery when there is insufficient slack for freedom of movement but insufficient tension to fully take the load, making the swimmer and survivor susceptible to shock loading. In this zone, as a wave lifts the swimmer and survivor, excess slack accumulates, only to be abruptly removed as they fall into the trough, resulting in a potentially dangerous shock load that can cause injury or damage to the hoist system.