A simple question that I could not find an answer to:
When is a sailplane a sailplane (from a regulatory point of view), especially a powered one of the TMG (touring motor glider) variety?
EASA has some quite simple definitions, presumably modelled over the similar ones from ICAO, according to which:
‘Sailplane’ means a heavier-than-air aircraft that is supported in flight by the dynamic reaction of the air against its fixed lifting surfaces, the free flight of which does not depend on an engine.
‘Powered sailplane’ means an aircraft, equipped with one or more engines having, with engine(s) inoperative, the characteristics of a sailplane.
‘Touring motor glider’ means a specific class of powered sailplane having an integrally mounted, non-retractable engine and a non-retractable propeller. It shall be capable of taking off and climbing under its own power according to its flight manual.
From this simple chain of definitions, it would seem that, for instance, a Cessna 152 could be classified as a TMG: It can take off and climb under its own power, and with the (non-retractable) engine inoperative it will do free flight sustained by its "fixed lifting surfaces", otherwise known as wings.
Since a Cessna 152 is not normally seen as a glider, I presume that there are more rules that need to be respected before a plane can be called a glider (or sailplane in EASA's classification).
I know that CS-22 contains the specifics, but is there a simple set of rules to determine if an aircraft belongs to the class of (powered) sailplanes as opposed to normal aeroplanes?