Bertrand Coconnier

> This is only a problem at a boundary case, right? Sort of. > > Just checking. The EOM has been verified against a few NASA simulations (several years ago),...

Oh yes , many thoughts but I need to put my ideas in writing. You made a good point but as far as I'm concerned that's not the end of...

First of all, I'd like to stress that the current issue is not the result of a formula that we are trying to use outside of its domain of validity....

> I can't say for sure what @jonsberndt's thinking is, but my guess is he was thinking that it could potentially be solved along the lines of the gimbal lock,...

> So if an aircraft is running down a runway due east with some velocity, then `w_b/v` would be 0 right? But `w_b/e`, i.e. relative to ECEF wouldn't be 0...

> > What I don't understand is why `vOmegaLocal` must be kept at all cost to initialize `vPQR` ? > > I'm not advocating for it be kept at all...

> It's also an issue when a satellite is initialized with a [polar orbit](https://en.wikipedia.org/wiki/Polar_orbit). In that case, the easiest way to initialize the satellite is to spawn it over the...

> So I'm leaning towards your point that `vOmegaLocal` shouldn't be used. Let's see what @jonsberndt thoughts are. Thanks. Let's wait for @jonsberndt opinion. > So the initial value of...

> 1. I think we all agree that JSBSim ought to handle flying over the poles (for instance) and we need to address any NaN's (etc.) that come about. Sorry...

As @seanmcleod [rightly pointed out](https://github.com/JSBSim-Team/jsbsim/commit/7115d781e80fda9388bf25ca7b25b79bdf8e9a6d#r64050717), we still have the issue of tan(90) blowing up when the frame `local` is selected for initial conditions: https://github.com/JSBSim-Team/jsbsim/blob/68c41368c5ca0f8d0f49acf219d0a4637a1f68ab/src/initialization/FGInitialCondition.cpp#L1417-L1425 Given that in that particular case...