Is a motorglider a "powered aircraft"

Is a motorglider a "powered aircraft"? Does anyone have official words
to this effect?

I asked our regional FSDO this question and he felt that a
motorglider was not a "powered aircraft", but I have heard from others
that it is.

I ask for reasons of certifying as a tow pilot in a motorglider. FAR
61.69 says that "no person may act as pilot in command for towing a
glider unless that person: (1) holds at least a private pilot
certificate with a category rating for powered aircraft."

Of course, I need a Glider ticket to fly a motorglider, but can I
also tow in a motorglider with a Glider certificate (assuming other
conditions are met), or do I need a Pilot-SEL certificate earned in
powered airplane?


My understanding is that a glider is a powered aircraft but not an
"airplane". Can anyone guide me on this? Thanks.

Greg