Nimbus 4DT accident 31 July 2000 in Spain.

wrote in message
ps.com...
Bill,

In fact, at least according to US regs, a winch launch IS an aerobatic
manuever.

I believe you are referring to the +-30 degrees pitch and +-45 degrees bank
definition of aerobatics. I believe there is an exclusion for aircraft for
which these are normal maneuvers. Gliders routinely exceed these values
thus they are not considered aerobatic for gliders.

But that wasn't my point. If normal recovery from a normal
operation places the pilot on the ragged edge of a deep stall, then I
think it best to characterize the operation as "ab"normal., requiring
reactions unique to that environment. And thus my toying with the term
aerobatic.

Normal winch operation does not place the glider on the ragged edge of a
stall. A normal launch places the max AOA very near that for best L/D. A
wire break handled properly with a prompt pushover is flown at a still lower
AOA with the airspeed not dropping below 1.3 x Vs or so. The margin is even
greater when you consider that the pushover is at less than one G so the
stall airspeed is lower.

The wire break training maneuver described by Chris is to show an instructor
candidate what can happen if the student is allowed to mis-handle the wire
break and is WAY outside normal operation.

The whole point is to drum into the instructors who will then insist that
his students learn that the nose must be promptly lowered well below normal
glide and the airspeed seen to be at a safe value and increasing before any
thought is given to a turn. This is to establish and maintain a large
safety margin. In many cases no turn is necessary and the glider lands on
the remaining runway.


BTW, have you demonstrated this maneuver without recovery? IE, have you
left the controls in place to let the spin fully develop?

Yes, It is a normal spin with a normal recovery at least with the trainers
in common use.

The wire break recovery being discussed here is safer and less dramatic than
the equivalent airtow maneuver consisting of a 200 foot AGL release on
departure and a turn back to the runway.

Bill Daniels