Boucles

The DHV have grounded a large number of harnesses with chest straps using automatic T-lock and Click-lock buckles (HSi10) made by the company, Finsterwalder Charly. This concerns numerous harnesses made by Advance, Ava-Sports, Apco, Finsterwalder & Charly, Karpofly, Sky Paragliders, Skytrekking, Sol and Woody Valley, as well as some harnesses used for paramotoring.

The DHV have issued a Safety Notice, legally binding in Germany, to stop using harnesses thus equipped, at the latest, four years after their production or, to be more precise, since the final control when they left the factory. The owners of such harnesses are asked to contact the manufacturer.  

According to information received by the editor of free.aero, this was, no doubt, triggered by the fatal accident involving a Polish pilot at the beginning of May in addition to another incident during a SAT. In both cases, the automatic Click-lock buckles apparently opened under load. The T-locks haven’t been involved in an incident yet but their design is identical to the Click-locks. 

The problem, according to the DHV, is the repetitive loading on these buckles or, more precisely, the cycles of diagonal load/unload which can, over a long time, wear out this piece of equipment. As a consequence, opening unexpectedly when loaded diagonally, can’t be ruled out. 

This only applies to the chest buckles, which are loaded and unloaded, unlike the buckles on the thigh straps which have hardly any pressure on them in flight. For buckles which are subjected to static, non cyclical load, the manufacturer has specified a 10 year life (the normal length of time in Germany).  

We think (and special care should be taken with this information which isn’t in the DHV statement), that the risk could in particular concern harnesses with ‘Get-Up’ type fastenings with two waist buckles. In flight they are regularly loaded and then unloaded. If one of them releases, there is a high risk of falling out.  

An English version of the DHV’s statement can be read here:

 

http://www.dhv.de/db1/source/technicdatareportnotes.php?lang=en&item=245