Reader Ed C. e-mailed me the link to this video clip after reading my previous post. Thanks, Ed! It depicts a hazardous helicopter rescue in Washington state in 2010.
From an article about the rescue:
At about 1830 HRS, after a quick 20-minute flight from Whidbey Island, the helo crew began looking for the rescue site. They had the scene coordinates, but this was a very rugged and forested area. They had been told that the patient was “near the bridge.” However, they were quite surprised to learn that she was actually under the bridge.
Flying under any bridge can be a dodgy situation for any aircraft, but there was an additional complication in this situation: The bridge had been constructed at a narrow point in the canyon—a canyon rich with trees that were approximately 100 to 120 feet tall with thick branches ready to shatter rotor blades and impale the helo body. But the Seahawk crew was up to the challenge. After all, the Navy had trained them to deal with such unexpected and difficult situations.
After trying different approaches and discussing the situation among themselves, the helo crew decided on this strategy: The pilot lowered the helo into the canyon under the bridge. He kept to the south side of the river where there were fewer obstructions. As the helo hovered approximately 40 feet upstream and 120 feet above the river, the crew lowered a corpsman with a litter into the river. The corpsman was directly attached to the hoist and the litter, which hung vertically during the lower.
Once the corpsman was in the river, the pilot kept the cable slack. The corpsman stayed attached to the hoist cable in case he got washed downstream in the river, which was 2 to 4 feet deep in this area. Carrying a litter and his medical gear, the corpsman began walking through the river ahead of the aircraft and approximately 120 feet to the patient.
During this time, the pilot continued the arduous task of maintaining hover. Throughout the 5 to 7 minutes that the pilot had to hold the hover, there was only approximately 10 feet of rotor clearance on the left and 20 feet on the right.
The corpsman finally reached the patient and those tending to her, which included two local medical personnel. These medical personnel had cleared the C-spine. The corpsman did a quick assessment and also cleared the C-spine.
The corpsman and ground rescuers log-rolled the patient and placed her in the litter, a collapsible-type litter with a metal frame and nylon bed. They then secured her in the litter with four straps.
To prevent a hazardous pendulum swing during the hoist, two members of the ground team helped the corpsman carry the litter back across the river so the hoist could begin from a position that was as close to directly under the helicopter as possible.
The Seahawk crew then began the hoist with the corpsman attached to litter, but now there was one additional problem: The narrowness of the canyon funneled the rotor wash, instead of allowing it to wash out at the bottom, as it would in flatter terrain. This resulted in the litter spinning. Fortunately, this did not have a negative effect on the patient or the corpsman.
It took only about 1 minute to complete the hoist and no more than 2 minutes before the crew had the corpsman and patient on board and secured. The crew then slowly backed the helo out of the canyon the same way they came in.
There's more at the link.
Some nicely calculated flying there. I reckon those pilots, and those from the 160th SOAR depicted in the previous post, could probably swap hair-raising stories for several hours!