Ext Collumn:
Immediate failure of extended collumn by ski weight
Sudden planer, propogation 2m out from ski tip.
Isolated collumn burp test:
1 light tap from elbow, sudden planer of top 15cm
3 taps from elbow, resistant planer 30cm from surface
Burp test #2:
1st light tap from elbow, sudden planer of top 15cm, partial collapse at 30cm
2nd tap, resistant planer at 30cm