Designer Lynn Williams says the latest British-built Flitzer variant to fly is the four-aileron Stummelflitzer Z-1S, a more compact, fully aerobatic development of the Z-21 homebuilt biplane.
Featuring, in addition to the second pair of slaved, mass-balanced ailerons, increased wing chord, rounded tips (to reduce roll-damping) mass- and aerodynamically-balanced elevators, this is the second Z-1S to fly. The other example, fitted with a Hirth three-cylinder in-line, geared two-stroke has been flying in Germany for some years.
G-ECVZ is powered by a more conventional 90 hp UL Power 260i horizontally-opposed four-stroke, fitted with a 69” diameter Hercules propeller that is designed, according to Lynn, to run at the beginning of the torque plateau to extend engine life. “The Type S retains all the good features of the Z-21 with a better all-round performance and greater roll-rate,” says Lynn.
Dan Griffith, who performed the LAA flight evaluation of Dudley Pattison’s prize winning Z-1R – the Rotec radial-engined variant of the Type S – described the handling as like that of a ‘lightweight Jungmeister’, “which was music to my ears, as you may imagine,” adds Lynn. “However, I think that the lighter Type S featured in the video clip will outperform it, being over 100 lb lighter.”
There were no issues with the aeroplane whatsoever and it is hoped that a flight evaluation by Dan Griffith might be performed in time for it to attend the LAA Rally on Sunday morning, but weather and work logistics might get in the way.
