Some simple Trig

Last night after I finished reassembling the helicopter I did some software work on the helicopter simulator . The sim is a full 3D 6DOF helicopter simulator with display. I downloaded it about 9 months ago and it works well. It was part of the source forge helicopter autopilot project. I've been using it to develop control laws for the real helicopter. Last night I changed my simulator control laws from having yaw always north facing to putting in a full transform from North, East to Forward Right for the position and velocity feedback loops. My helicopter sim now flies the full NG-LLC flight profile while doing slow 2 deg/sec rotations the whole time. It all works so the next stop for this code is the "real world " helicopter.