The Skyleader factory were not satisfied with the 'flutter' resistance of the GP One's T-tail, having experienced flutter at 135 kts (16 kt above Vne).
So, in conjunction with the technical university at Brno and the Stemme glider factory, they researched and developed a modification that increased the theoretical 'flutter' speed to more than 194 knots (360 kmph). Subsequent flight tests proved the mod was successful.
Over New Year, the factory sent the carbon parts out to NZ. The upgrade consisted of an external carbon transition piece to stiffen the boom-to-vertical fin joint, plus a series of carbon/foam sandwich ribs to be fitted inside the tail fin.
Bill Barber, known in NZ for his series of carbon fibre 'Snark' designs and for helping build several
carbon 'Furio' aircraft kits, came up to Wanaka to help install the upgrade.
The fin is certainly a lot stiffer, so that alone will alter the 'harmonic' frequency that might induce flutter.