At 19:09 24 November 2017, Dave Nadler wrote:
On Friday, November 24, 2017 at 2:06:20 PM UTC-5, Dave
Nadler wrote:
On Friday, November 24, 2017 at 1:44:35 PM UTC-5,

wrote:
...Has anyone done an engine test run like this?

I almost forgot: A well-known German manufacturer did this
at the factory
last year (mighta been 2015), and trashed the new glider and
trailer
bound for their USA dealer...

Can't make this stuff up!

Don't do it! I used to do this with a DG400 but I had a proper
substantial steel frame to hold the fuselage (it anchored via
the wing pins). Even with this system the whole procedure felt
very unsafe, especially at full throttle; it also took far longer
than driving to the airfield and rigging the glider properly.
Dave W