Thanks for this advice... I thought I'd take a short-cut and swap out a few Chinooks at Gutersloh.
Sadly the Puma appeared not to share the clever STOL habit of the CH-47, and waddled along the runway without getting airborne.
I then dropped the MAIW Grob Tutors AFD file into the sim, and went to Benson.
Plenty of Pumas, 3 taxied out to the runway, where the first wagged its tail down the entire 6,000 ft of runway.
The remaining 2 had long expired in exasperation when it headed off into the meadows beyond, resolutely glued to the ground.
I am trying to think of some kind words about this package, but none are forthcoming...