Fundamental Pilot Hoist Technique:

Hoist Habits: Under excellent conditions, helicopter pilots can get away with suboptimal technique. However, I encourage disciplined use of best practices during favorable conditions so pilots ingrain habit patterns that will allow crews to excel in challenging hoist conditions.  

Trim: Make trim work for you. Take time to dial it in, set it, and leave it. Many pilots are in the habit of rapid fire (“machine gun”) trim. Under good conditions with ample visual cues, trim technique can be inconsequential. However, a rapid fire (“machine gun”) trim will be detrimental in situations with minimal cues (e.g., maintaining position on dark nights) or when cues are misleading (e.g., maintaining position over a large expanse of moving white water after a breaking wave). Under demanding conditions, pilots must be able to use force trim as a reference/baseline to maintain a consistent hover. 

Hovering with minimal cues is akin to trying to balance while standing on top of a large ball in a dark room and using a pole for assistance. When the pole stays firmly on the ground, it can be leaned on to improve balance but when the pole is raised off the ground and placed back down in a different position, balance is more difficult.  Similarly, every time pilots re-trim with minimal cues, they are picking the pole up, rendering what could have been an excellent reference for maintaining control useless. 

When hovering with minimal cues, re-trimming should be deliberate and occasional, not a subconscious habit conducted almost every time the flight controls are adjusted.  

Trim the hover to a zero relative motion with the crew’s hoist target.  

• For underway hoists, before positioning the helicopter over the hoisting location, trim to eliminate relative motion between the helicopter and the vessel (often described as flying “formation” with the boat).  

• In more challenging vessel hoist scenarios, where the vessel is surging then slowing with sea state, trim to the mean speed (there will be another post dedicated to boat hoisting in seas). 

• For hoists of people in the water (swimmers and/or survivors) and hoists to vessels that cannot make way (“dead in the water” – DIW), pilots should trim to a steady zero relative motion hover as well. When there is no current, this is a zero-groundspeed hover. With a current, the zero relative motion trim position will be a hover that is moving at the speed of the current. These zero relative motion trim positions in a current are established when the helicopter is offset from the swimmer/survivor. The trim then provides a critical baseline for effective hoisting when the helicopter moves over the top of the swimmer/survivor and the pilot can no longer use the swimmer as a visual reference. 

• Collective trim is paramount when altitude hold is disengaged. Pilots should trim the power setting that maintains the target altitude and work against the trim as they temporarily tilt the rotor arc and/or when there are temporary changes in relative wind. When positioning the helicopter in a hover during calm wind days, a slight power increase is necessary to maintain level flight. When the helicopter begins to move, a slight power reduction is then necessary to maintain level flight when the helicopter stops its motion. The RADAR altimeter will help cue the pilot to climbs and descents in calm seas but in larger sea states, the RADAR altitude constantly increases and decreases as waves move under the helicopter. In these situations, the instantaneous vertical speed indicator (IVSI) will have to be harnessed to help indicate climbs and descents.   

Tempo: A precision hoist will often be more efficient when pilots take the time to ensure the helicopter is well trimmed and stable, prior to commencing the hoist. Before moving in to complete a vessel hoist, pilots should settle the helicopter 15-20 yards from the hoisting area in “formation”. I also encourage pilots to be in a stable zero relative motion hover before moving in to pick up the swimmer. 

Rate of closure: The faster the rate of closure, the more difficult it is to manage cable. Furthermore, arresting rapid rates of closure requires large control inputs and power changes. During precision hoists in calm seas, there is generally no such thing as a rate of closure that is too slow when the helicopter is near the hoist target. 

The only two exceptions are no wind “dead in the water (DIW)” hoists and no wind swimmer hoists. During these hoists, it is possible to move the helicopter slow enough that the rotor wash is moving the object in the water faster than the helicopter is closing on it. That said, crews can still complete these hoists effectively with five knots or less of groundspeed. Slower rates of closure allow for better cable management and smoother, more consistent evolutions. 

The flight mechanic (hoist operator) conn of “slow your rate” and “increase your rate” has improved the Coast Guard MH60T community’s ability to adjust to the appropriate rate of closure mid hoist because the hoist operator can see the leading edge of the rotor wash and often anticipate the effect of the rotor wash on the object in the water. When the pilot is no longer visual with the object, the flight mechanic gets real time feedback of the rate of relative motion between the helicopter and swimmer/survivor. The “increase your rate” conn is particularly useful when the swimmer/survivor is being pushed away from the helicopter due to rotor wash and/or current. 

Altitude: Altitude selections are based on several criteria: 

• Obstacle clearance 

• Visual cues/sight picture – lower increases cues and improves sight picture 

• Rotor wash – higher minimizes rotor wash impact which improves conditions for people in the water and allows smaller, lighter vessels to remain on course. 

• Cable swing – higher the more potential for swing and spin 

• Fly out/away – higher increases the chances of not landing on top of the vessel or swimmer/survivor in the event of a power loss. 

• Illuminated obscuration (“milk bowl” – mist lifted by the rotor wash in the pilots NVD field of view on low wind nights) – higher decreases the effect on pilot disorientation and improves the ability to have a visual horizon (decreasing lighting in front of the aircraft such as securing or redirecting the search light can also minimize the effect of milk bowl) 

Typically, vessel hoists will be a compromise between sight picture and obstacle clearance, whereas swimmer/survivor hoists will be a compromise between the ability to move away from the swimmer/survivor in the event of a power loss and optimal visual cues. 

Fixation: Pilots tend to cling to their only solid visual reference (e.g., a small piece of bow), leading to pilot induced oscillations (e.g., as the bow moves up and down, the helicopter moves forward and back). 

Additionally, a hover scan “down” provides precision, an “out” provides stability. If a pilot does not scan “out” to the horizon, it will be difficult to maintain a stable hoist platform. Lastly, if a pilot uses a single point of reference for a sight picture, the reference may not change with movement (e.g., the small triangle of bow a pilot is using for a sole hover reference does not change if the helicopter moves down and forward or up and back). Scanning also helps pilots recognize an altitude change, which would otherwise be difficult to perceive, when they are fixated on one object (more on hover cues in another post).  

Control inputs – size: With calm seas and consistent winds, MH60-T cyclic control inputs will ideally be limited to a six-inch diameter, which is about the size of the circle created by touching your thumb and index finger. When a pilot, who is new to hoisting, is overcontrolling the aircraft, to provide a visual reference as the non-flying pilot, I will slide my “hand circle” over the cyclic. The flying pilot should be able to conduct a hoist while rarely touching the non-flying pilot’s hand over the cyclic. If the cyclic is repeatedly banging off the non-flying pilot’s hand, the flying pilot is working too hard. Take note of how much the cyclic is moved during a hover over the ramp or runway and aim to use the same control input size for your precision hoists over water. 

With altitude hold off and during calm sea and consistent wind, the collective should rarely be moved more than a few inches from its force trim reference point. 

Control inputs – timeliness / anticipation: An experienced helicopter pilot knows that if pilots want to move a few feet and then re-establish the aircraft in a stable hover, they must put in the appropriate control inputs to initiate the movement then take the movement out with an appropriate counter input. With lots of visual cues, the pilot leads the helicopter with the appropriate counter control input to stop over the desired spot. However, when visual cues are lacking, because motion is more difficult to perceive, pilots fail to anticipate the counter input that stops the movement until it is too late; the helicopter is at or past the intended hover location, which leads to overshooting. 

Similarly, there is a tendency to over control the helicopter. With lots of visual cues, helicopter pilots make an input, then neutralize the controls and wait for the helicopter to respond to their input. With minimal cues, there is a tendency for pilots to hold a control input until the helicopter moves, which generally results in more movement than intended. Recognizing these tendencies allow pilots, who are new to night overwater hoisting, to better anticipate the control inputs necessary to initiate and stop helicopter movement. With repetition, hovering control inputs with minimal cues will become second nature to pilots in the same way hovering with significant visual cues has. 

In addition, pilots should remain cognizant that they are flying the rotor arc from a fuselage that is suspended from the rotor hub (bear with me on this one…). For example, if a pilot is sliding right and looking down at a small piece of bow and the pilot arrests that slide with left cyclic, the fuselage suspended below the rotor arc will swing to the right, causing the small piece of bow, being used as a reference, to continue to decrease in size for a brief period after the helicopter is stopped. The greater the inertia, the greater pendulum. Once the inertia has been expended, the fuselage will return to the left and again find equilibrium suspended below the rotor hub. Although being able to anticipate the change in sight picture resulting from fuselage movement will also become second nature with time, recognizing and understanding this phenomenon speeds up the process.