Flattening to the Engagement Plane from Interception by two predatory fly species is explained by a proportional navigation feedback controller

Data were rotated onto the engagement plane, defined by the starting position of the fly and the two points of greatest displacement of the target. The plane has axes X & Y while distance orthogonal to the plane is in axis Z. The summed displacements between fly and target in each dimension are given for Holcocephala and linear (i.) & erratic (ii.) targets and Coenosia linear (i.) & erratic (ii.) targets. The Z dimension is removed when correlating the rotation in pursuer heading with rotation in the LoS.