Expert: Heiko Hanusch - 8/7/2007

Question
With regards to the Moravan Zlin Z242-L,
As you alter the weight in the aircraft, it begins to fall into different categories according to the Pilots Operating Handbook (POH). There are three categories, Normal (N), Utility (U), and Aerobatic (A). Within each of these categories their maximum loading weights are respectively as follows, 2400kg, 2350kg, and 2140kg. However the maneuvering speeds (TAS) respectively are, 121 Kts, 134 Kts and 143 Kts. So, my questions is why does the maneuvering speed increase with the decrease in weight in this situation. What makes this aircraft able to induce a faster speed with less loading and not be at risk of structural damage. I realize it is an acrobatically designed aircraft but I still cant figure out why the maneuvering speeds are contrary to my knowledge.

Answer
Hi there,

Thanks for your question. It does seem contrary to what you have learned at first but upon closer examination you'll notice that the g-limits increase in each category and there is your answer. The weights are based on category g-limits and not just g-limits in normal cat.If  the airplane is designed just in normal cat the upper limit would be 3.8g's and all weight calcs would be based on that upper limit but since aerobatic has 6g's, although the weight is lighter the margin to get to 6gs is higher hence allowing a higher TAS.(original design)
this "recategorizing" just allows the manufacturer a greater range of use for their airplane.
Remember though, the airplane can only be used for aerobatics up to 2140kg!(which was the original design)