How do you encode a radial to radial turn in ARINC-424? I am building my own ATC simulator and for that purpose I need to include several instrument procedures. I have a problem with that particular one:



My problem is on KEA transition, the leg between "RDL 256 KEA" and "RDL 192 ATV" how should the transition be encoded in terms of ARINC-424 path terminator sequences.

Specifically it's the turn from the one leg to the other that bothers me: "RDL 256 KEA" seems to terminate on either 27 DME KEA or RDL 187 ATV. But then what? There is a 20 DME ATV on the next leg that spoils everything. CD (or Course to DME) is not a specific route over the ground so the previous turn won't be able to intercept it. I could either omit the CD part or insert another CR (course to radial) before the CD leg but then I'm not doing what the map says, I improvise. So my question is am I conceiving this wrong, or the IAC is ambiguous in this particular point?
So you fly the KEA transition like this:


Track RDL 265 KEA until crossing RDL 187 ATV or 27 DME KEA
Start a right turn and intercept RDL 192 ATV
Fly RDL192 until intercepting final


As egid said, RDL 187 ATV is a lead radial which is a radial used only to tell you when to start a turn.

As far as 20 DME ATV, it is actually only used for the PELAG transition so you can ignore it in this case.