I once had one spoiler fully out due to a failure of a diecast aluminium
bracket in a Grob Astir. This broke in flight, with a loud bang as the
left airbrake suddenly sucked open and stayed there. I then found that I
needed almost full right aileron and rudder to conteract the roll and yaw
to the left. I was only about 900ft AGL at the time.

The solution I worked out was to open the the other airbrake, which still
worked, and then make the best more or less straight ahead landing that I
could into a field. I had to sideslip the glider to get in, but walked
away from it and didn't further damage the glider.

BTW, this and another case is why many Grob Astirs have a little perspex
inspection window under the wing, so that you can see the offending
bracket.

Getting back to the original subject, we do teach no airbrake approaches
in the UK as a post solo exercise, just in case the airbrake mechanism
fails, or the brakes freeze shut while wave soaring. I have made a video
of such an exercise, but you float an awfully long way in ground effect,
which is why I eventually told the student to open the brakes, as it was
the last flight of the day and we wanted to stop somewhere near to the
hangar. See:

http://www.youtube.com/watch?v=5t7xnls2w5k

This was done in a K13, which sideslips very nicely and very much more
effectively than most glass gliders. With a lot of slip on, the ASI will
usually totally misread.

Derek Copeland

P.S. I know the Yanks call a sideslip a 'forward slip' before someone
pulls me up on that!


At 02:02 11 September 2009, vaughn wrote:

"Mike the Strike" wrote in message
...
I do know of one where the spoiler handle on a Grob 103
broke after they had been deployed and jammed full open, resulting in
an off-field landing.

And I know of a case where just one spoiler deployed on a glider.
Causes
a
nasty uncommanded roll. The only solution (once you figure out what is
going on) is to close the spoilers and proceed without them.

Vaughn