For those that have the my short take off demo, they will find it hard to believe , its possible to get in somewhere a little EXTRA short , but believe me if you push it , you better be ready, when somewhere I cant make a step turn , I have found my EMERGENCY ROPE can save the day, you have to find a light cord your thrust will break ahead of time , Taxi to shore,  tie the tail over the bank and tight to a tree, then just get in and firewall it , I would be the last to admit its happened ...but.. 

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  Even though it was an April first post, it makes sense when you're talking about floats and skis, where you don't have a brake option.  May I make a suggestion when using this method?

You cut the rope/cord, so that you have a short piece attached to the aircraft, preferably by a hitch, and long piece attached to shore, also with a hitch.  Then use a sheet bend to attach the aircraft rope to the shore rope, as close to the aircraft as practical.

 

The breaking strain at the sheet bend will be approximately half that of the rope, and the hitches should be much stronger than this.  This way, you control where the break is going to happen.  Otherwise, you might have it break at the far end, and with the recoil, it may end up fouling control surfaces or even wrapping itself around the propeller.

 

Decent quality 6mm cord would beak at around 1,500 lbs at a sheet bend, so probably 5mm cord or less, tested for an appriopriate breaking strain at a sheet bend before hand is probably the way to go, otherwise you might find it too hard to break.

 

Cheers,

Paul

Paul -

Just wondering why the sheet bend (my favorite Boy Scout knot) breaking strain is half of the rest of the rope?

Thanks - Brad

G'day Brad,

Most knots greatly reduce the breaking strain of rope. It's because of the bending radius and twists. If I recall correctly, some of the rather involved climbing knots can get to about 97% of the ropes breaking strain. But most knots are less than half. A double sheet bend, if combined with hitches to stop it slipping, will do close to 60%. But interestingly, if you don't do that, it will usually come undone at about 37%. Which could be handy in this application, if you wanted to reuse the rope.

Cheers,
Paul

ME and granny knots get along fine, the tail tie down is sharp enough to aid in cutting the rope, but thanks for all the cool suggestions 

Yep, the plans tie down can do that, which is one reason some people choose not to use the plans tie down. ;) Anyway, you've got the break point controlled, which is the main thing. That's all I was worried about, someone trying the technique and getting the break at the shore end.

If they don't slip, granny knots are good for around 57%, but they almost always slip long before then.

I presume everyone is familiar with the practice of using a rope secured next to the cockpit, with slip knots at both ends, so you can do run ups conveniently, then simply pull the free ends of the rope into the cockpit when you want to go?

Cheers,
Paul

I am not - please describe the method/technique

Dave

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