Notice that if you put the array in a balance beam you get the longest length. Length of the array is important because the more surface area an array has the longer the potential detection range. The bad part of it is that the array can be dangerous against side winds and crosswinds. I'm not really surprised that the Y-8 Balance beam plane crashed. On some of the US planes, you have the arrays back to back going across the length of the dish. That's two arrays, mind you, and they offer the largest reception area possible as you can see. The thing is, you need to mechanically rotate the arrays. Those movements and shifts in positions create shifts in gravity in the plane that affects the plane's stability. Without any movement and the advantage of using an aerodynamic dish, the triangle arranged phase arrays as you can see might offer the best compromise between array size and flight stability.