On Sunday, March 24, 2019 at 3:50:51 PM UTC-4, Pete Wizz wrote:
Hi There,

I have an certified glider registered in US, glider has been send to Europe for a little tuning recently. Part of this is an electric front sustainer which according to Europe regulations should be certified too but is not during to local bureaucracy. I am not sure if the glider should stay there for a year to give them a chance and finishing the job as planned or pack it up in to shipping container and get back to US. My question is how complex could be to register this 'powered' glider as experimental.
Any help very welcome, thanks in advance.

Pete

This is a good case for moving to experimental, given significant change to the ship. An experienced DAR can help accomplish this and issue the new airworthiness certificate, with operating limitations.
It will require completion of phase 1 flight testing to demonstrate that it operates as intended, usually about 5 hours in a specified area. Upon completion of testing, a statement is made that it is controllable in all phases of flight, and possibly some other requirements specified by the DAR. Then it goes to phase 2 normal operation in Experimental, Exhibition, and Air Racing.
It will be very helpful to find a DAR that has done this before. Do not expect your local FSDO to know how to do this.
Been there - Done that.
Good luck
UH