New Zealand June 14, 2018
The pilot died after the aircraft crashed on the west coast beach, near Waiuku, late Thursday afternoon. Police on the scene said it appeared the hang glider suffered a "catastrophic failure" which caused the glider to fall to the ground and the man died on impact, "The hang glider hit the ground with a very big bang...," a witness on the scene said.
https://www.stuff.co.nz/national/104729450/Police-CAA-and-hang-gliding-association-investigate-Karioitahi-Beach-crashThis can happen when the crossbar is not properly secured during set-up.
Failure to notice a bent tang or frayed side wire can also be the cause. Tensioning the rigging can place high stress on a kinked wire, resulting in a failure at a later time. If you have a glider with a slight bend in the cable near the tang, it could be the result of a bad set-up in the past. Inspecting the wire is not always good enough. Internal strands could be broken where you can't see.
Replacing flying wires periodically is the best policy, particularly if there is any suspicion. I bought my own Nicopress tool and learned how to use it for maintenance on my gliders.
Used gliders should always be inspected for stainless steel hardware where the wires attach. I have found gliders "repaired" by dummies who used aluminum to replace stainless tangs! Unlike stainless steel, flat-plate aluminum under plastic stress work-hardens to the point of brittle failure. When subjected to repeated flexing, it eventually will fail at a later date. Likewise, bent bolts should never be straightened with a vice or hammered. Always replace them with new aircraft-spec bolts.
http://www.aircraftspruce.com/catalog/hapages/tag304.php?gclid=EAIaIQobChMItv-qr5nb2wIVCsRkCh0cxgXUEAQYAyABEgKXlfD_BwEAnother potential point of failure is frayed stiching or worn straps that secure the crossbar. Likewise the integrity of the tensioner. Older gliders used pins to secure the tensioner. Sometimes pilots would forget to secure the tensioner with the pin and it would pop loose in flight. When your crossbar hinge moves forward, the crossbar becomes much weaker and exerts greater force on the rear keel attachment point. If something ever goes wrong with your crossbar tensioner in flight, you must immediately fly very gently to a landing.
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