Back in the late 60’s/early 70’s ( I think ) there was a test program called Project High Drink, wherein a USN SH-3 was to hover for extended periods at 10,000 ft, refueled by a flexible metal fuel line. Kurt Cannon was the project test pilot and Larry Russel a senior test engineer. They did the flying at the Augusta Ga. airport as I recall, but I do not recall what the purpose was. I do recall seeing pictures of the ground support equipment, fuel line on a huge reel etc. They did a bunch of flights, but that’s all I can recall.