Losing Visual Reference with the Vessel While Hoisting (“Lost Target”)
In the Altitude and Heading Considerations During a Hoist post, I emphasized the importance of maintaining a reliable hover reference on the vessel for the flying pilot. Due to vessel size, obstacle height, and cockpit visibility limitations, the required hoist altitude can restrict the pilot’s line of sight to only a narrow sliver of the vessel. In such situations, even a small climb or lateral drift can result in a complete loss of the pilot’s vessel reference. In the Coast Guard helicopter community, this condition is known as “Lost Target.”
Unplanned Lost Target is treated as an emergency. Losing a visual reference on the vessel during a hoist significantly reduces hover precision over a hoist target and can result in sudden divergent motion between the helicopter and the vessel. If the rescue device is below obstacles when the pilot experiences Lost Target, it can lead to fouling the hoist cable—which may require shearing or risk the cable parting—or dragging the rescue device or swimmer off the deck, potentially through railings, rigging, or other hazards. Effectively managing this emergency demands timely cable control and clear, concise conning from the flight mechanic, along with smooth, deliberate aircraft control from the pilot.
When Lost Target is called, the Coast Guard flight mechanics are trained to provide clock position and distance cues (e.g., “Hoist area is 6 o’clock, 20 feet”). During these moments, providing positional references relative to the aircraft (e.g., “Hoist area is under the tail wheel”), trend information (e.g., “You’re drifting forward, easy back”), and helicopter rate information (e.g., “Slow your rate”) helps the pilot regain visual reference while minimizing unmanageable relative motion. The flight mechanic should also anticipate divergent motion, preemptively pay out cable to buffer movement without unnecessarily increasing snag risk and be prepared to shear the cable if required.
For pilots, the key to effective recovery is minimizing the time spent without reference while maintaining controlled motion. A common error is moving too aggressively to regain the lost reference, which can result in separation rates that the flight mechanic cannot match with cable payout. This can cause the rescue device or swimmer to be dragged, snagged, or yanked through obstacles. Instead, pilots should maneuver gradually and deliberately to regain reference and be ready to immediately stop relative motion once visual contact is reestablished.
In the Fundamental Pilot Hoist Technique post, I emphasized the importance of setting and maintaining force trim throughout a hoist. Under good conditions with ample visual cues, trim technique can be inconsequential. However, under demanding conditions, such as Lost Target, pilots must be able to use force trim as a reference to maintain a consistent hover. Without force trim set as a stable hover reference, Lost Target recovery has a high probability of devolving into an unmanageable situation. A well-trimmed helicopter and slow, coordinated aircraft movement gives the crew the best chance to recover without damage or injury.
In the Hoist Dry Run post, I discussed the importance of positioning the helicopter overhead the target hoist area prior to commencing the hoist. A dry run is critical when hoisting to smaller vessels. It allows the crew to assess rotor wash impact, identify snag hazards, determine the feasibility of the hoist area, and adjust helicopter heading and altitude to optimize visual reference. It also provides an opportunity to adjust the vessel’s heading and speed to ensure a more stable ride and minimize the effects of rotor wash and sea conditions. Furthermore, the dry run gives the pilot insight into how much of the vessel will remain visible during the actual hoist. While calm conditions may allow for hoisting with only a small portion of the vessel in view—such as a few feet of the bow—variable vessel movement due to seas or rotor wash may require more of the vessel to remain visible as a hover cue to decrease the probability of going Lost Target. The more variable the vessel movement and the smaller the visible portion of the vessel, the higher the likelihood the pilot will go Lost Target amid the hoist.
In a hoist situation that has the potential of going Lost Target, rehearsing recovery procedures is critical. Similar to how crews prepare for inadvertent IMC, crews who brief for and anticipate the possibility of Lost Target are far more effective than those caught by surprise.
In rare but necessary cases, a hoist may involve a planned Lost Target phase—for example, hoisting to a sailboat with high masts. Before accepting this risk, the crew must evaluate all viable alternatives, such as changes in heading or altitude, adjusting the hoist location to the bow or stern, conducting the recovery from the water, or hoisting with the helicopter on a steady course and speed while the small boat approaches the helicopter (a separate post). In addition to alternative courses of action, crews must also assess whether the hoist can be accomplished using a trail line, whether the vessel can maintain a steady course and speed, and whether there is a clear exit route away from obstacles.
To reduce the risks associated with Lost Target, the Coast Guard frequently uses a trail line—a 105-foot polypropylene line with a 300-pound weak link connected to weight bags to reduce whipping and sail. After the trail line is delivered to the vessel, it is connected to the hoist hook. A rescue swimmer or boat crew member pull (heave) on the trail line as hoist cable is paid out. This allows for angled delivery of rescue devices or swimmers to the target area, while the helicopter remains in a hover with reference to the vessel.
When delivered, the trail line is handheld. If it is necessary to go Lost Target to deliver the trail line and the line snags, the flight mechanic can jettison it and use a backup; standard SAR loads include multiple trail lines. The trail line effectively extends the reach of a stable hover position and allows crews to deliver the rescue device with minimal exposure to obstacles and less reliance on an overhead hover.
However, it’s important to understand that while a trail line permits angled delivery, recovering a rescue device often requires a near-plumb position. Like landing in a confined area and not being able to depart due to increased power requirements for takeoff, the geometry of hoist recovery must be considered carefully prior to committing to a course of action. If obstacles exist, recoveries can occur with a slight angle only if the horizontal force is not excessive—too much swing can cause the device to strike obstacles or descend into the water.
Effective, intentional Lost Target hoists usually involve a very slow, deliberate approach, with the helicopter slowly sliding until the pilot loses reference, followed by a “hold” over the hoist area, followed by the pilot smoothly moving back to regain visual contact in a matter of seconds. During the few seconds of Lost Target the rescue device is delivered or recovered, and during the portion of the hoist where the helicopter is approaching the hoist target, the cable is managed with catenary. The faster the rate the helicopter is moved into the lost target area and the longer the duration the pilot is lost target, the higher the probability of an unsuccessful hoist.
The Coast Guard helicopter community rarely disconnects the basket from the hoist hook while the basket is on the deck of the vessel. However, in dynamic vessel hoisting situations (Lost Target or otherwise) in which helicopter control and/or cable management is going to be difficult to maintain throughout a basket delivery and recovery and the hoist is still warranted, crews should consider disconnecting the basket from the hoist hook until the helicopter is stable and ready to take the load. This mitigates the risk of the basket being pulled from the deck if an extended precision hover is not possible.
In conclusion, Lost Target—whether planned or unplanned—is a real and recurring challenge in vessel hoist operations. Unplanned Lost Target, especially when the rescue device is below obstacles, must be treated as an emergency. However, if a vessel’s course and speed is steady, with excellent crew coordination, a well-executed Lost Target hoist can be a controlled, manageable event. Dry runs, proper use of force trim, timely cable management, and smooth recovery inputs are all essential tools to prevent what might otherwise become a rapidly escalating situation. Whether during training or in rescue operations, crews that anticipate Lost Target scenarios and rehearse for recovery are far more likely to resolve them safely and effectively.