Hi Jim,
That is really interesting. I always though we were about 7 - 9 degrees. I am pretty convinced that the rugby ball as drawn is what I like to see from the CTB. I have to say that the drawings were really done to convince non-aviators in my audience as to the "Concept" of the CTB an I certainly did not measure anything in process. Maybe the middel drawing is too steep when it is replicated on paper.
When we fly to 23 at ABZ I think the CHAPI there is set to 7 degrees (I will check) and the square on the runway which we use as a helipad seems to be at the right "Ovality" - accepting that is in fact a square.
CTB - I choose this rather than anything with the words "Decision" in it as we have passed the ARA MAPT and the "Committal" point for a Class 2 With Exposure" has not yet been reached. If anyone can come up with a better acronym that would be great.
It does what it says on the tin "Call the Ball" but I think as a previous poster remarked it is a bit "Hollywood" even for my tastes.