Notice Regarding ParkZone Extra 300
Shortly after launch of the ParkZone Extra 300 (PKZ5180 and PKZ5175), ParkZone began receiving some reports regarding the low-speed handling qualities of the aircraft. Common reports are that the aircraft pitches up on takeoff, that it tip stalls during landing, or that it “flicks-out” in a tight turn. At the same time, some customers have noticed an anomaly in the wing tip consisting of an inverted semi-symmetrical airfoil or flattened appearance of the upper surface. This asymmetry is happening as a result of paint shrinkage or installation of the blade spar in the lower surface of the wing during manufacturing. Some have stated it appears as if the wing was painted upside-down from the intended design, and claim that this wing geometry is affecting the aircraft’s flight performance.
The intended aft battery location is where the hook-and-loop strap just wraps around the end of the battery (see photo 2), which is incorrectly shown in the instruction manual as the recommended forward cg location, 3” aft of the wing’s leading edge. This location is actually the recommended aft cg.
Some customers have purchased the Extra 300 expecting to use it for 3D flying. However, the ParkZone Extra 300 was not designed for 3D flight; it was designed for sport aerobatics or precision aerobatics. Its wing loading is too high to be a good 3D performer. Moving the cg aft and increasing elevator throws in order to achieve 3D will result in very poor landing characteristics and low-speed handling qualities, as well as pitch instability, consistent with some of the difficulties that have been reported. By moving the cg forward to the intended location and keeping elevator throws low, the Extra 300 performs very well in the intended flight regime.