Helicopters at sea

[stilton]

Don't know much about helicopters, but have always been impressed.

My question is, having seen Helicopters operate at sea landing on frigates I noticed them using some kind of winch device to attach the Helicopter to a grate of some kind on the stern whilst airborne.

To my uneducated eyes it would appear that this is to aid recovery in rough sea states, but am very curious as to how this works and the techniques used.

Thanks for any and all information.

[NorthSeaTiger]

This device you have seen is a "Harpoon" which once the aircraft has landed indeed attatches to the deck to prevent the aircraft moving in rough sea states etc, some aircraft use negative pitch to "suck" the aircraft to the deck.

[diginagain]

Sub-min pitch on the Lynx, and a sharp crew with the tie-downs.

[Wunper]

Stilton

"some kind of winch device to attach the Helicopter to a grate "

Device on your side of the pond its more likely to be the Bear trap

http://www.readyayeready.com/timeline/1960s/beartrap/

W

[VTA]

Royal Navy Sea Kings.....No Harpoon, No haul down system, just great big cahoonas on the pilots..I used to love it, but night time would raise the pucker factor a tad!!! My wife took care of the cahoonas a few years later!!!

[stilton]

Thanks for the information, particularly interesting was the 'Beartrap' device.

I'm still unclear on one aspect of this operation though, in the 'Beartrap' case does this imply that the helicopter would not only take up the slack but (forgive the ignorance I only know fixed wing) apply inputs to generate vertical lift whereby the Helicopter is actually 'straining' to climb away against the cable, and , in turn is winched down thereby keeping very tight control of its lateral movement?

[bellsux]

Recovery, Assist, Securing, and Traversing (RAST) aka Beartrap. Helicopter gets connected to it by a cable on the ship and the ship then pulls it onto the deck. Then the beartrap catches the helicopter and drags it back into the hangar after the blades have been folded ect.

[Thomas coupling]

Fantastic piece of kit, but it made a rod for the canadians backs because they could operate in sea states other nato ships couldn't so they got all the sh**y night tasking!

With a limit of 31 degrees roll and 8 degrees pitch. there is NOTHING anywhere in the world that can compete with these mad nutters!
I have been sitting on deck ready for launch - at night and a wave has engulfed the S61 and flamed one of the engines out!!!

You'd sit there rocking around feeling first the stbd then the port wheel lift off the deck like a sumo wrestler about to engage!

Recovery at night onto a 3000 ton bucking bronco is enough to age any pilot 10 years!

You move across the heaving deck, wait for the quiescent period (which lasts about 5 seconds) and then prey to God that you've hooked on and are being hauled down.

Very well trained and very brave pilots those canadians - hats off to them.

After shut down, another part of the beartrap system (attached to the tail wheel), is used to traverse the helo squarely into the hangar. All of this is done by the haul down officer whose head sticks out above the helideck inside a bulletproof bubble.

I was 'straightening' an S61 after it had shut down slightly askew on deck, in minus 30 degree OAT with ship heaving, when the tail wheel didnt want to straighten. The haul down hydraulics ripped off the tail wheel assembly and catapulted the entire arrangement overboard at Mach3!!

The 8 ton helo then "dropped" onto the deck from about a foot sending a booming shudder throughout the frigate.

Captain was not impressed and wanted to know why a 'brit' was running amok on the back of his boat!!

Great memories, but very hairy times - never to be repeated