Oh dear!

[Mr Mal]

We have 40 and 60 foot dongas blow over mine hi walls..... unfortunately sometimes with miners in them. Anyway long story short they duck bill them into the groung with a 5/16" cable attached. Essentially a smaller version of a sand anchor which is hammered in at about 30 degree angle with an OZITO hammer drill and a 1.2m extension. It goes in with the fin straight and any movement the bill opens up and increases the grab size.

 

All that is left out of the ground is the cable and if they come loose you have bigger problems then your plane blowing away!

 

They are about 10 bucks each with cable and the hammer driver runs 200 bucks - so if your doing a permanent tie down thing it might be a good thing - holds a donga should hold a plane right???

 

 

[Mr Mal]

For those interested.......... http://ancorloc.co.nz/products/duckbill-anchors/