motorglider engine test

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!

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

On Friday, November 24, 2017 at 11:09:47 AM UTC-8, 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!

I've seen a fuselage-only engine test at Kirchheim, they have hard points outside the shop especially for it. Been present for some engine stand runs at Williams. Quite a nice rig Rex has, using the glider's engine controller, etc. with the engine out of the glider.
I've done one run on the back of the trailer with ASH26E. Didn't take it to full power, seeing no need.
A little forward of the normal rigging position on the trailer, using the trailer ramp as a chock, since the 26 landing gear swings forward of the doors. Saw horses with a 4x4 through the spar box for torque control. Worked as planned.
But you're right to be nervous. The amount of pucker factor involved makes assembling the glider seem a better choice. While you're at it, keep the pilot current too.
Jim

On Friday, November 24, 2017 at 2:50:52 PM UTC-5, JS wrote:
On Friday, November 24, 2017 at 11:09:47 AM UTC-8, 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!

I've seen a fuselage-only engine test at Kirchheim

Right, SH was not the manufacturer I mentioned above ;-)
Though I can think of some of their customers who've damaged
their plane/motor trying what the OP suggests...