SAR winching capability

[CHINOOKER]

A question to all those that either "dangle" at the end of a cable or hover above it.....Is there a maximum height,(cable length permitting obviously),at which people can be safely winched from on SAR helicopters??. Having seen several of the documentary type programmes,(ie Seaside Rescue etc),where a Bristows S61 is featured winching a casualty from the base of some seaside cliffs,i would assume that the actual helicopter would need to have quite a safety margin built in regarding height!
In respect of this,when called out,do you need to know the exact situation someone is in before you respond?
Thanks.

[Wader2]

Chinooker, I don't know the answer from a shopkeeper's role but as a customer I know they used to have 'jungle penetrators' in the far east to get a line down through a jungle canopy. The penetrator was a little like a ships anchor and the survivors could sit on the 'flukes' or seats, 2 at a time.

I don't believe they sent a winchman down and I would not have liked to have been dragged up through the small hole made by the penetrator. I guess the line length would have been comfortably longer than 200 feet and possibly 300 feet.

[[email protected]]

Chinooker - the short answer is that the selected operating height of the aircraft is a compromise between pilot's references, the ability to attain safe single engine (SSE) flight or commit to a suitable landing area, the winchman's escape route in the event of trying to achieve SSE and the likelihood of worsening the survivor's situation with the downwash.

Ideally the risk is limited by winching the casualty as little as possible but it depends which of the above factors is deemed the most overriding at the time. For training you would aim for 10 -15' over land and 50' over the water - if the winchman goes out above these heights he will initially be on a monkey harness to prove the winch but could then face a 'space walk' with hundreds or thousands of feet of fresh air underneath him if the terrain is difficult.

As for your last line - we try to find out as much info en route but the assessment will be done on scene and a cunning plan hatched to rescue the casualty.

[Role1a]

Crab

The short answer is 245ft and No.

R1a:ok:

[Winch-control]

The long answer is that you never know the winch height pre scene.The safe height is the lowest height acceptable to do the job, or maybe...somewhat higher...(safe single etc)
When called out there is no requirement for this info, just the location is enough, the crew will do the rest!
The experts in the field take care of it all..Easy really!

[SARREMF]

Crab

You are Sooooooooooooo last century! Fly an aircraft that has a single engine performance! Tusk tusk!

Cheek and tongue!

[Oldlae]

The Air Equipement hoist used on the Bristow SAR S61's was designated a cable length of 90 meters (300 feet), incidently it has a breaking load of 3000 lbs and SWL of 600 lbs. Interestingly, it isn't anchored to the hoist but depended on a number of wraps around the drum for security and is coloured to indicate to the winch operator when the safe length is close.

[Aaaaaaaaaaaaaaaargh!]

Interestingly, it isn't anchored to the hoist but depended on a number of wraps around the drum for security and is coloured to indicate to the winch operator when the safe length is close.:eek: :eek: :eek: :eek: :eek:




what colour? Shiny?

[Oldlae]

Shiny isn't a colour. The cable is galvanised and there were a lot of experiments to find a dye that would stick, last I heard, some time ago the colour was red.

[Cabe LeCutter]

The cable is probably shiny because it is made of stainless steel if it is the same as all the other hoists that I have seen. Breeze and Goodrich both use stainless cable consisting of 133 strands in 2 layers. Stainless of this type will rust if not cared for correctly. The cable is usually anchored to the drum but will only take a strain of 50 - 70 pounds, that is why the wraps are so important.

Head down. Look out for the flack

[taxydual]

Makes no difference what the colour is when the hook end drops off!!

Mare Harbour 1987. Have you dried out yet Vaughan?

[CHINOOKER]

Gent's,
Many thanks for your posts on this subject,they have been both interesting and enlightening in equal measures!.
FWIW,today i had an e-mail on this subject from a former USMC HH53 pilot,(via another forum), who stated that he quite often practised lifting "volunteers" out of the pacific rim jungles using the method described by Wader2......He said his winches regularly exceeded 250-300ft,mainly due to the tree canopies being so high!!
Just thinking about that,makes me appreciate the job you guys do a whole lot more!! Cheers All.

[Aaaaaaaaaaaaaaaargh!]

The cable is probably shiny because nobody ever dares wind it out that far.

seriously though, is this so that it can be easily jettisoned if it snags on something?

[alwayslookingup]

To be able to release quickly would make sense. However, that means doing it this way you'd have to wind it all out, and possibly very quickly (eg caught up on a pitching, rolling ship in the North Sea in a winter storm). I seem from the dim and distant past SAR helos being equipped with explosive operated tungsten shears which could be operated to instantaneously cut the wire in emergency. Or am I just talking bolleaux?

[Avtrician]

On the Hueys, the cable had a detonator that would fire a blade ("V" shaped) on to an anvil, chopping off the cable as it went. We also carried a manual cutter (dont know that I would like to try it tho). I Seem to recall that the last 20 or 30 ft was red, and I think the first 10 was green (To let you know to slow down)

[alwayslookingup]

So I wasn't dreaming, there is / was an explosive wire cutter in existence. Avtrician, did you ever see it used in anger?

[Oldlae]

The cable used by Bristow on the Air Equipement hoist was/is definitely galvanised steel wire and not stainless steeel.

[[email protected]]

Alwayslooking - the cablecutter used to be a direct service from the battery on the Wessex and, at one airshow when loads of kids were queueing to look in the cockpit and cabin, one little darling flipped up the yellow and black guard on the cyclic and pressed the button thinking he was firing the guns! There was a loud bang followed by and anguished howl of pain as the winch hook dropped onto another little darling's head as he stood by the cabin door. We had to disconnect the battery for static displays after that.

On the SAR Sea King, the hoist changes from the fast range to the slow range within the last 7 -11 feet of normal (not red) cable giving another clue that you have a lot of cable out. If the microswitch that does this is disabled ie when using the manual overide (pots) then the cable can be winched right off the drum as has been demonstrated in the not too distant past - tee hee:)

[Winch-control]

Yes Crab and as you well know re proven to ensure it is safe, though you may not believe it. The orange sector does show in the last 10ft .And Unless the a/c system is at fault, the system works great. Yes it has failed (once)?? in how many thousands of lifts??? and even that is not (to my knowledge) proven..as a winch failure..
safe height chinooker? about 3 inches! Safe winching height well 0 to 245ft
how far would you like to drop?
and No the guys do not know the situation prior to arrival....

[[email protected]]

G - I was referring to a winch weight check that didn't go as planned - happened at Watt after you departed these shores. The Radop (who shall remain nameless) proved the warning in the FRCs, that the microswitches don't work when using the pots, is extremely accurate. Anyway he won the inaugural B Flt precision bombing competition:)

[minigundiplomat]

Ah AIDU is back. Thank God. I missed you mate. There is some new bloke called 1.4G knocking round looking for a dust up, but he does not have your wit.

seriously, good to hear your keyboard strokes.

[Winch-control]

So safe winching height? Yes it is RN not RAF..The senior service do the job too!:oh:

http://photos-f.ak.facebook.com/photos-ak-sf2p/v248/39/78/671695310/n671695310_3167237_8651.jpg
Taken from the hook, only approx 10ft below the a/c....beautifull view, but a bit chilly that day!:D
I should add I was at least 3 inches of the ground (maybe a little more) and all the a/c systems were working normally!