Heavy Seas and Surf – Swimmer Deployment Techniques
The following are the ten most common coaching points when training aircrews on swimmer deployments in heavy seas and surf. They focus on anticipating environmental factors, selecting swimmer placement, and managing cable dynamics to execute effective deployments in challenging sea states.
1. Anticipation Starts with Environmental Awareness and Predictive Positioning – Anticipation begins the moment the helicopter arrives on scene through a thorough assessment of the environment. Will the swimmer be deployed to board a vessel, enter a life raft, or rescue a person in the water? How close can the aircraft approach before rotor wash affects the target? Is the object stationary, drifting, caught in orbital motion from large rolling waves, or being pushed by breaking waves? If the object is moving, does the swimmer need to be deployed ahead of its path, allowing currents or wave action to close the gap? Or should the swimmer be positioned alongside the object’s path to avoid hazards, such as a capsizing vessel? Every scenario requires the crew to anticipate where the swimmer needs to be—not just now, but where they must be in the future—to execute an effective rescue while mitigating risks in a dynamic environment.
2. Deploying after the Crest – Aircrews aim to deploy the swimmer on the backside of a wave to maximize the time available—ideally a full wave period—for the swimmer to disconnect and prepare to manage the next wave.
3. Committing to Harness Deployments – During deployments where the swimmer will disconnect from the hoist hook (e.g., harness deployments), the flight mechanic must place the swimmer in the water and immediately provide enough slack to allow them to get off the hook—ideally between waves. “Committing” to the delivery means putting the swimmer in the water and paying out cable promptly so they can disconnect efficiently.
4. Committing to the Direct Delivery – During a direct deployment—where the swimmer remains connected to the hoist hook—the flight mechanic must ensure the swimmer has enough slack to prevent being pulled or jerked as the wave passes and the water drops out beneath them.
5. Swimmer Hand Signals – As the swimmer is lowered beneath the helicopter, they have a much better perspective of their position relative to the approaching wave crests than the flight mechanic. Swimmer hand signals are essential for keeping the swimmer at the correct height above waves—high enough to avoid contact with the wave face or crest, but low enough to enable a timely and efficient deployment onto the backside of the wave.
6. Good Enough is Good Enough – In direct deployments where the swimmer remains on the hook, we often carry over a training scar from calm-condition operations: the tendency to fine-tune the swimmer’s position to deploy him within an arm’s length of the survivor (2-3’). In dynamic environments, chasing perfection can waste time without improving outcomes—especially when the survivor is moving with each wave. Good enough is good enough. Timing the deployment between waves can be far more important than getting the swimmer a couple more feet closer to the survivor.
7. Minimizing Swimmer Swings during Deployment – In big seas and surf, I need to remind myself that while responsive and more purposeful maneuvering of the helicopter will likely be necessary during the recovery, during the deployment, assertive maneuvering will induce a swing of the swimmer on the cable making the deployment more difficult for the flight mechanic. We can avoid a swing during the deployment with smooth control inputs and gradual acceleration of the helicopter. When we recover the swimmer and survivor, we will deal with the swing that resulted from committing to the pickup after they are safely out of the water.
8. Establishing Cable Management on a Direct Deployment – In dynamic maritime hoisting environments, once the swimmer is in the water, effective cable management is essential. The helicopter must be maneuvered in concert with cable inputs to keep the swimmer or survivor properly positioned with the right amount of slack—enough to allow freedom of movement without introducing an entanglement hazard. Every hoist involves a catenary, and in rough conditions, this likely means more cable in the water than in calm seas. Larger waves require additional slack to account for the orbital motion—rise, fall, push, and pull—of rolling seas and the surging motion of breaking seas.
9. Catenary without an “Easy” Conn – In calm seas, catenary evolutions typically involve “easy” conning commands—gradually moving the aircraft away from the swimmer while slowly paying out cable. In heavy seas, however, this approach doesn’t translate well in establishing appropriate energy management (wave energy → RS/survivor → hoist drum). While every situation is different, the dynamic nature of large waves often requires a more assertive response: quickly paying out (“dumping”) cable and repositioning the aircraft efficiently to place the swimmer and survivor between the approaching wave energy and the helicopter.
10. Aborting a Free Fall – During a free fall deployment, the crew estimates the helicopter’s height above oncoming waves using the RADALT to observe average wave height and an outside scan. If the margin between an oncoming wave and the helicopter is too small, an “up, up, up” call by a crew member prompts the helicopter to climb to avoid a large wave. Because the swimmer has already been given the signal to deploy and is off the internal communication system, the flight mechanic must bear hug/tackle the swimmer and bring them back into the cabin to avoid a free fall from a dangerously high altitude.