Vertical Surface Hoist – Techniques
The following are the 11 most common coaching points when training aircrews on hoists to vertical surfaces.
1. Physical grip and Short Haul Contingency – Amid the crew brief, quickly discuss the physical grip/short haul contingency. Occasionally, survivors leap onto the swimmer when they get within a panicked survivor’s reach. In other cases the survivor’s perch is so precarious that there is not an opportunity to rig a rescue device. In either case, it is beneficial to have a plan of what to do and where to go in that situation or in the case of cable damage.
2. Traverse Route Pitfalls – When briefing the traverse route, I find it advantageous to discuss the areas to avoid in addition to the specific route. In a real-life case where the rescue operation almost never goes as planned, we must be flexible and prepared to follow the swimmer’s signals with some pre-established “guard rails.” Examples of areas on the vertical surface to avoid are places where the cable could be snagged or rubbed, corners that could lead to a loss of positive contact and a large swimmer swing, or cracks/crevasses that would be difficult for the swimmer to navigate across. Establishing guard rails on the insertion area is also beneficial (i.e., no closer than this and no farther than that).
3. Cheat High – There is a pilot tendency to want to be close to terrain because of the improved visual references. However, as pilots approach the insertion point, they should start high. Rotor wash can blow a survivor from their perch and can send debris down on top of them. Furthermore, turbulence from wind interacting with terrain can increase power requirements and significantly decrease precision. It is easier to come down for better visuals than to climb when you realize the rotor wash is potentially affecting the survivor’s ability to hold on.
4. Good Enough is Good Enough on Insertion – We complete an overhead check to assess the rotor wash effects, verify power requirements, establish visual references and validate the target hoist area. Then we conduct a static hoist straight down to a pre-determined insertion point. As the swimmer’s body interacts with the rotor wash flowing off the vertical surface, they are pushed away from the vertical surface and might start to swing. In these cases, “good enough is good enough.” Trying to be precise typically makes the swing worse. Avoid keeping the swimmer just above the surface “tapping their toes.” Allow them to get their feet on the ground, knees bent, this is the first step in gaining positive contact.
5. Exaggerated, Slow Hand Signals – Swimmer hand signals communicate critical information to the flight mechanic. We emphasize slow and exaggerated with the “level off” signal putting a “period on the end of the communication” (e.g., down signal – level off – point into cliff for positive contact – once positive contact is established – level off – left signal – when swimmer is the appropriate distance to the left – level off, etc.). Bright cloth on gloves and arms of the swimmers make hand signals easier to receive by the flight mechanic during high hoists.
6. Awareness of the Communication Chain – It is important for swimmers to recognize that there will be a slight delay between when the hand signal is provided and the ensuing helicopter response. For example, the swimmer provides a signal, the flight mechanic receives the signal and then provides a conning command to the pilot, who slowly and smoothly affects a small movement of the helicopter. Swimmer awareness of this gap in response time improves patience and anticipation.
7. Positive Contact – Once the swimmer has their feet on the vertical surface, ideally knees bent, the flight mechanic conns the helicopter into the vertical surface to create an angle on the cable. As that angle is created on the cable, the flight mechanic will need to pay out cable to keep the swimmer in the same position.
8. Plumb with the Drum – Once positive contact is established, the traverse starts. Throughout the traverse, the swimmer, flight mechanic, and pilot work in concert to keep the swimmer plumb with the hoist drum. The flight mechanic can often see when the swimmer is not plumb because he has significantly more weight on one of his legs in the rappelling position. If left uncorrected, the helicopter can pull the swimmer across the face of the vertical surface.
9. All “Easy” Movements – Vertical surface hoisting is a scalpel hoist. As the swimmer navigates the face of a vertical surface in a side shuffle manner while the flight mechanic manages positive contact with cable and helicopter position, the helicopter must move at a rate slower than a walk.
10. Hold What You’ve Got – During a standard hoist evolution, when a rescue device or swimmer is on deck and still connected to the cable, the flight mechanic pays out a small amount of cable to provide slack, allowing the pilot to return to the optimal hoisting altitude after an inadvertent climb or descent. However, because the cable is taut throughout a vertical surface hoist evolution, the pilot should not return to their previous altitude following an unintentional deviation. Instead, the pilot should “hold what they’ve got” because another change in altitude will require another flight mechanic adjustment.
11. Retrieving the Survivor from the Vertical Surface – When the swimmer has prepared the survivor for the hoist and given the ready for pick up signal, the flight mechanic slowly moves the helicopter to a position that is directly above the swimmer and survivor. As the crew takes the angle out of the cable, decreasing positive contact, the flight mechanic must take in cable to keep the swimmer and survivor at the same position on the vertical surface. In addition, if the hoist drum is not directly over the top of the swimmer and survivor when the swimmer loses positive contact, the cable will swing in the direction of the helicopter as the force of gravity returns the cable to the plumb position, dragging them across the face of the vertical surface. Because it is difficult to eliminate all swing when they lose contact with the vertical surface, as soon as the swimmer and survivor are free, the helicopter should accelerate deliberately to avoid a swing back into the vertical surface.
