BRS chutes. Why doesn't everyone use them?

On Mon, 24 Jan 2011 01:36:45 +0100, Andreas Maurer wrote:

- NO BRS has ever been tested in an extreme situation (one wing or
tailplane gon, violent spin, high positive or negative g-loads).

With all due respect, this is not correct. There are two BRS uses I'm
aware of where it was popped after the aircraft shed a wing and both are
the subject of videos:

- An Archaeopteryx ultra-light glider lost a wing when over-stressed
in a loop at the 2010 Coupe Icarus. http://vimeo.com/17923312

- An RANS-7 lost a wing during an aerobatic display in Argentina.
http://www.youtube.com/watch?v=jgfG2DfPB6I

I'd agree that retro-fitting is problematic: I can't imagine how you'd
get a BRS into any glider with exposed spar stubs, e.g. a Libelle, ASW-19
or Discus 1. Even where it apparently just slots in there may be problems
that aren't obvious until you fire it. I've always been worried by photos
of a BRS installation in an HP-14 (I think it was a 14) that show the BRS
webbing straps wrapped round the centre section spar. The thing that
bothers me is that the straps pass round the protruding edge of an alloy
L extrusion, so there's apparently nothing to stop it from cutting the
webbing during the initial opening shock. I'm not an engineer so this may
be perfectly fine, but the sight still makes my teeth itch each time I
see that photo.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Jan 24, 5:23*am, Martin Gregorie
wrote:
On Mon, 24 Jan 2011 01:36:45 +0100, Andreas Maurer wrote:
- NO BRS has ever been tested in an extreme situation (one wing or
tailplane gon, violent spin, high positive or negative g-loads).

With all due respect, this is not correct. There are two BRS uses I'm
aware of where it was popped after the aircraft shed a wing and both are
the subject of videos:

- An Archaeopteryx ultra-light glider lost a wing when over-stressed
* in a loop at the 2010 Coupe Icarus.http://vimeo.com/17923312

- An RANS-7 lost a wing during an aerobatic display in Argentina.
*http://www.youtube.com/watch?v=jgfG2DfPB6I

I'd agree that retro-fitting is problematic: I can't imagine how you'd
get a BRS into any glider with exposed spar stubs, e.g. a Libelle, ASW-19
or Discus 1. Even where it apparently just slots in there may be problems
that aren't obvious until you fire it. I've always been worried by photos
of a BRS installation in an HP-14 (I think it was a 14) that show the BRS
webbing straps wrapped round the centre section spar. The thing that
bothers me is that the straps pass round the protruding edge of an alloy
L extrusion, so there's apparently nothing to stop it from cutting the
webbing during the initial opening shock. I'm not an engineer so this may
be perfectly fine, but the sight still makes my teeth itch each time I
see that photo.

--
martin@ * | Martin Gregorie
gregorie. | Essex, UK
org * * * |

What do you mean by exposed spar stubs? How are they more exposed,
and to what, in the 19 rather than say the 24, 27, 28, and 29.

Andy