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





Single spoiler deployment has caused at least one fatal accident.

If a linkage fails resulting in asymmetric airbrake deployment it is
possible to run out of options very quickly.

My thoughts are that you need to open the brakes to balance the drag and
lift asymmetry. Then you can fly the aircraft through the resulting
descending roll and recover. Depending on your height and speed it may
be quite pressing to land, it may also be quite pressing to reduce speed...
However - if this happens in a high energy state (where else?) you may
already have a lot of yaw and roll inertia by the time you get the other
airbrake open. Especially on a long winged open class ship there may
just not be enough control authority left, and if you are very fast
and/or very close to the ground the options are limited.

To overcome the differential lift caused by the yaw you may need full
rudder.
To limit the speed and avoid terrain you may need large elevator deflection.
To reverse the roll and return to level flight you almost certainly will
need full aileron.

You are unlikely to find such a high G, rolling pull up close to , or
over Vne with airbrakes deployed in the manual.

There is a reason for that "max manoeuvre speed" entry...

A little math says that at 250km/h and 300m (~1000")AGL a 30 degree
descent angle will give you less than 8 seconds to avoid terrain.