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How do they hover in the open ocean?


Curyfury

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Just saw a video of the coast guard doing an off shore hoist which got me thinking, what points do they use for reference? Even when the hoist operator gives foward/backward/ side to side guidance, you still need a refernce point, right? I would think looking at the water would just make you dizzy and any landmarks may be too far to see.

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Auto hover linked into GPS radar Alt, VERY expensive kit usually on a 4 axis auto pilot system

Loosing horizon over water is a quick way to kill your self, spacial awareness is surprisingly easy to loose

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The MH60 Jay hawk has the CAAS cockpit. The position hold system references your position off of EGI and will remain in a constant position from where it was referenced.

 

Additionally the system has a hover page which allows the pilot to hover off of a cue in the cockpit while never actually looking outside, it is a very solid system and can be trusted to land vertically in 0-0 conditions.

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Altitude and position over open water at a hover are very hard. Did a leak check on a gas pipeline in the Gulf, you'd think a defined area of bubbles would give a good reference- no. From a good 15-20 feet above the surface to 350' without being able to see a change.

Landing on a small barge under tow with a really small pad and lots of obstructions, good approach, stable hover over the pad, as soon as I turned the tail to clear the surface crap, I'd lose visual contact with barge, except for one whip antenna. Peripheral visual cues on the running seas was almost vertiginous.

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It's difficult to do by eye. I used to do a lot of slingloads to small platforms offshore, and it's some of the hardest flying I've done. At a hover over the platform, you can't see it at all, only the water, and you have to maintain station using the 3" convex mirror mounted under the chin bubble, facing aft, and it doesn't show much other than the load. That's why I don't look at the horizon, or way out in front at a hover or while picking up or setting down. That works well on land, but not at all offshore, and most of my time was logged offshore. I got so used to looking down right where I was that it's ingrained into my muscle memory. Holding a precise hover over nothing but water isn't possible without electronic assistance.

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On the Pave Hawk we either use our heads down display, which has an excellent symbology system presumably based on the CAAS, or at night we'll have the backenders toss chem lights into the water for references as well. Most of the younger guys just hover heads in on the symbology cues, even during the day. As Joe said, it also allows us to do restricted visibility approaches entirely heads in. Despite all that, it can still go south quickly over the water as you can very easily end up blowing the people you're trying to pick up around (even maintaining a "perfect hover") if you don't drop the extraction device (rope ladder, hoist, etc.) directly to them within a few seconds. Some times a "perfect hover" over the water is actually a 5kt crawl in a given direction. Couple that with being completely engulfed in salt spray at 10' for some of our devices, any sort of decent swell height, and it gets sporty quickly.

 

We do have an improved automated hover system these days, but it functions erratically during the times you'd need it most (power limited, large gust spread or wave heights), so a lot of guys don't practice with it either.

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We have Phold (hover button) in the CH47F, as well as an EXCELLENT HSD-H display, which is a real time hover display complete with a velocity vector and acceleration cue. It makes hovering in 0/0 possible. So over water, it works really damn well.

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Hmmm I didn't realize the 47 had a velocity vector and acceleration cue. I was a 47 FE before I got picked up. Wish I had paid more attention to all the instruments in the cockpit the pilots had at their expense when I was calling a fast rope, sling load, etc. We have them on the 64 but just assumed we were the only ones.

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Hmmm I didn't realize the 47 had a velocity vector and acceleration cue. I was a 47 FE before I got picked up. Wish I had paid more attention to all the instruments in the cockpit the pilots had at their expense when I was calling a fast rope, sling load, etc. We have them on the 64 but just assumed we were the only ones.

 

We have it in the 60M too. Position Hold just isn't as good as what the 47 has.

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