Jelly: I thin k it's horses for courses. The Gazelle TR take off is simply another cog running from the planetary gear in the MGB simples.
In this type of a/c, when the engine stops for any reason including hi speed shaft failure - you enter auto and the MGB drives the TR. Simples.
In the 206/350, during auto the MGB drives a reduction GB which in turn drives the TR.. which in itself is 'awkward' and unnecessary
BUT THEN you have to have the engine running AS WELL to drive the FPT to drive the reduction GB to drive the TR....in case you experience a hi spd shaft failure?????
Where in the design team @ Aerospatiale did they have a shift of ideas about single engine drive train layout...just out of curiosity. For better or worse
