Hover Coupler Employment
Hover coupler – because our community underutilizes the hover coupler, pilots usually need a refresher on the coupler’s use. While in a coupled hover in the MH-60T helicopter, the trim switch on the cyclic allows for a max of 10 kts groundspeed acceleration and deceleration from what is set on the potentiometer. Therefore, if a crew sets 10 kts groundspeed on the potentiometer, the pilot flying can use the trim switch to accelerate to 20 kts groundspeed and decelerate to a steady hover (0 kts groundspeed). By pressing the trim button, the helicopter resumes the groundspeed set on the potentiometer (10 kts) regardless of the speed adjustments made with the trim switch.
Hover coupler common errors – Occasionally, during a high workload event or with a pilot who is lacking familiarity with the hover coupler, the pilot will try to climb and maintain a new altitude employing the means by which pilots change the RADAR altitude hold in the MH-60T (climbing with the collective trim button depressed, then releasing the collective trim with the expectation the helicopter will maintain the new current altitude). However, with the hover coupler engaged, the helicopter will return to the altitude set on the potentiometer. Hover coupler altitudes can only be set on the potentiometer.
At times, there will be a reason to affect a manual instrument takeoff (ITO) with the hover coupler engaged. Crews will fly the manual ITO and, at some point, release the collective trim button, resulting in one of two outcomes:
- An alarming immediate descent for 10-20’, followed by an abrupt stop in the descent. Even though the airspeed and altitude holds engage, the abrupt, seemingly erratic helicopter behavior still alarms the crew.
- The helicopter decelerates and descends to get back to the hover coupler altitude and ground speed settings.
The pilot who realizes these behaviors are due to the hover coupler still being engaged efficiently disengages the mode and eliminates unnecessary crew consternation, allowing them to focus on the next task.
Pilots pride themselves on hand flying precision hovers and although pilots need to continue to hone this skill, it has been my experience that engaging the hover coupler regularly, for brief periods, is good for our community as well (twist, twist, push).
Quick “sea story”… During my first annual Proficiency Course (annual week of training in the simulator), I was paired up with an O5 (Doug Cameron), who was an accomplished Coast Guard H60 pilot. It was apparent that he had worked hard at his craft for years and was currently still doing the work. His current position, the Operations Officer at CGAS Sitka (a flying OPS job), required him to still be fully engaged in operating helicopters in service to others. I learned a lot working with him that week, mostly through his example.
We were in the sim, in poor, simulated weather conditions. Because of the lack of fidelity (year 2000 sim version), there was little to look at, but it was good enough to realize that we flew over a person in the water with a flare at 300’ and 70 KIAS. My training partner called “mark, mark, mark” to store the position in our flight computer (what we called the “TACNAV” then) and then maneuvered the helicopter (simulator), largely on instruments, into a turn. As we rolled out and slowly descended, approaching the marked position, he asked me to set 80’ and 0 kts groundspeed in the potentiometer. As we approached a hover, he asked me to engage the hover coupler, which at the time, I had never considered doing (note – the 60J community did not have a visual approach to the water checklist).
Up to that point, I had only seen the hover coupler automatically engage after a full PATCH checklist, an instrument pattern, and instrument approach to the water (automatic approach). When asked, I engaged the hover coupler, after which we slowly approached the marked position while we both looked to relocate the PIW. Without the hover coupler, both of us would have expended the majority of our bandwidth manipulating the controls and monitoring drift and altitude as we tried to remain stable without visual references, forcing us to rely largely on our crew to conduct the search (four eyes compared to eight in a real scenario).