Unsheathed upper cascade lines.

Steve Purdie's picture

Ref. no.: FSC.SC12 British Hang Gliding Date: 02/2016 Pages: 1 (Pink) and Paragliding Association Ltd
8 Merus Court
Meridian Business Park Leicester
LE19 1RJ
Tel: 0116 2894 316 Fax: 0116 289 8741 www.bhpa.co.uk

SAFETY ADVISORY

Issued by Angus Pinkerton - Chairman of the Flying & Safety Committee 15 February, 2016.

All Paraglider Pilots must READ, DIGEST AND TAKE ACTION on the contents of this Notice and keep it for future reference.
This notice will remain available on the BHPA website and in the Technical manual.

Unsheathed upper cascade lines.

The BHPA has received a report of the unsheathed upper cascade lines on an Ozone Alpina 2 paraglider becoming knotted and tangled in flight whilst the glider was flown in big-ears mode with the speedbar being operated. This incident occurred when the lines were dry and in good condition.
Subsequent investigation has revealed that this issue has occurred several times and on more than one glider.
It is likely that the very light lines are becoming tangled when under no load (i.e. loose) in a turbulent airflow when the glider is accelerated. It is possible that this effect could also be experienced as a result of an asymmetric collapse.
Ozone is aware of this issue, and states that as any changes to the line specifications would move the glider outside the certification, there are no plans to modify the lines.
No control issues have been reported as result of this characteristic, but any change in the line configuration could have an effect on the gliders’ recovery behavior in subsequent instability situations.
Whilst the reports currently only refer to this particular model of glider, it is considered likely that a similar phenomenon is possible on any glider that uses very light unsheathed aramid upper cascade lines.
If your glider has experienced a similar problem please complete and submit a BHPA incident report form (available on the BHPA website).
Pilots are urged to be vigilant about this issue, and visually check their gliders carefully after using big ears or after recovering from a collapse, especially when in accelerated mode with the speedbar. Where possible the use of an alternative method to lose height is recommended.
Minor tangles may be possible to clear by using deep brake, but any pilot who notices that their glider has acquired knots or tangling is advised to land as soon as possible.