Think you would have to go back to the end of WW2 when th Hoverfly first emerged in Burma ,flying out casualties,then Korea,and later Malaya.Then look at French operations in Indo-China,Algeria,and nearer home in the Alps.One of the major problems was really a need for another crewmember to operate the `hoist`,and usually hoist cables were not very long(50-60ft),either pneumatically/hydraulically powered,with a limited number of continuous `cycles`up-down,before overheating.
As Ken says,the SAR Training Unit was at Valley for training pilots and crewmen(usually navigators/AEOs/loadmasters/Signallers )re-roled to go to SAR squadrons at home or abroad,so mountain flying and winching was part of the Course.So,any pilot not on the `fly-pro` that day would end up ,either stting in a dinghy in Holyhead harbour(in an immersion suit),or being hauled around in the water on the end of the cable..One was also allowed to try to winch another`volunteer` out of the dinghy....all good fun.....
I was later posted to a Support Helicopter Squadron in Borneo,which did not have `crewmen`,only Regiment Gunners,not trained as `winchies`,only to fire our heavy armament,..2 x Bren guns mounted in the cabin in the event of going into `hot LZs`.However we did have a Navigator,a very well-respected SAR winch operator who had recognised the shortcomings of the winch on Whirlwinds and was trying to develop a system to allow pick-ups from the jungle where the trees were up to around 200ft tall,so any aircrew who ejected would be better off staying in the trees,rather than climb down.However ,it was difficult to `engineer`,and the hoists were operating in high temperatures,and likely to fail at a most inappropriate time...
So,`mischief` being the `Mother of Invention`,we used `abseil tapes`,later known as `lashing-tape`,4inch wide fabric tapes in a roll of about 250 foot lengths,attached to the paratroop rail,and a loopknot hooked on the winch,with a `rescue strop`/horse-collar` for the downed flyer/trooper.We would also use 2 tapes,and a sandbag as ballast to penetrate the trees.Since we had no loadmasters ,the job of winching,dropping the kit and conning the pilot was left to a `junior`pilot to do..So,we may have invented the first `long-line` rescue system...and soon enough we had our first `customers`...for real...an SAS patrol of 4 ,who were `on the run` from the `unfriendlies`,unsure of their postion,but they had a SARBE beacon.. I,being a`junior newby`now had the job of hopefully picking them up if they reached a particular LZ ,,,,,,,,,OR ,we would use the longline..And so it was,they were in heavy trees,and nowhere near the LZ..out went the tapes and ballast,hopefully not hitting anyone,and then followed many gesticulations that we could only pick-up 2 people at a time...the SAS don`t like to split a patrol up,and eventually the got the message..I can`t recall if their Sarbes had a `voice ` channel that Dick,the pilot could communicate with them,or not...Anyway ,we had 2 hooked,even if they were sitting astride the strops,and up to 200ft above the treetops,took them to a an LZ a couple of miles away,put them on the ground,pulled in the tapes and went back to get the other 2.Repeated as before,then got all 4 on board and headed home..One of the last pair had got caught in the top of a tree during the recovery and had lost his Armalite,and thought he`d be court-martialled,but he wasn`t..
We had to do a similar pick-up ,at night,in heavy rain ,and thunderstorm,of a wounded Gurkha soldier,from the `unfriendlies` side,using a stretcher,but I was still the `junior`to the senior pilots,but I was `more experienced` as a `winchie`...all in a days/nights work...