Photo shows failure in duralumin mast section during a recent storm.

Tube, 50mm D 5mm wall, did not bend. It appears to have stretched / fatigue cracked at the thrust bearing at the top of the mast, then let go. A semicircular piece tore out for the last horray.

The 40mm D 4mm wall aluminium top mast section did bend.

Although pattern at failure point looks like it was welded but inside the tube shows it wasn’t.

Any ideas???? 73 VK4AMG