Concerning: Reserve release system, harness size XS and S
A pilot reported increased deployment forces during trial deployment in an SIV training.
The subsequent investigation from the DHV and Skywalk revealed the following:
- If the deployment is performed by pulling directly away from the harness (as designed in the outer container), the forces are below the maximum value of 7 daN required by the construction regulations
- If the pulling direction is 45° degrees or more upwards or sideways the deployment force can exceed 7 daN. Forces up to 10 daN were measured. This higher deployment force was especially evident when the pull was performed slowly. The reason for the high deployment force is that the ends of the deployment handle have to rotate when pulled upwards or sideways. When this rotation occurs the stiffness at the end of the deployment handle creates friction in the closing flaps and a higher deployment force is evident. (Photo 1)
Photo 1: CULT 2 XS and S, Original deployment handle
- When mounting the deployment handle of the successor harness Cult XC, which has soft ends and a optimized shape, the deployment forces are about 5 daN irrespective of the direction of the pull. A trouble free deployment was always possible. (Photo 2)
Photo 2: CULT XC Handle with optimized shape and softer end pieces.
- The increased deployment force when pulled 45° degree or more upwards or sideways could only be observed with harnesses Cult-2 of the size S and XS. Even so this was a singular case and the increased the deployment force was only evident in special circumstances (Slow pulling of the handle, upwards and sideways) Skywalk advises the owners to exchange the deployment handle.
Owners of a harness Cult 2 size S or XS are asked to contact Skywalk.
Grassau, 19.11.08
Manfred Kistler,
Manager
Skywalk GmbH
Bahnhofstraße 110
D-83224 Grassau
www.skywalk.org
info@skywalk.org |
