The Martin Baker code found at http://www.euclideanspace.com/maths/geometry/rotations/conversions/quaternionToEuler/ specifies the following... "This depends on what conventions are used for the Euler Angles. The following assumes the standards here... Euler angles Heading = rotation about y axis Attitude = rotation about z axis Bank = rotation about x axis Euler angle order Heading applied first Attitude applied second Bank applied last" i.e. YZX rotational order. So I guess that we need to determine the rotation order for each actor, and adjust the calculation accordingly. Do you agree? Konan