RNAV non-precision 1

25.10.2004

Answer or Commentary:

(I.W:

As we have had no replies to this question as yet, I will try to answer it.

Firstly I would draw the protection areas associated with the straight portion of the procedure.

Then I would do the easy part, which is the inner area of the turn. Calculate d1 to find the intersection of the secondary area and the d1 line. From there, draw the line of 170° and using this line tidy everything up. At this point it would be very tempting to just join the areas on the outside of the turn, to close up the green area. However to continue as per Figure III 31.3 in Pans-Ops.

If the calculated value of d2 is negative(as in this case) the d2 line is down track from the waypoint. This extends the primary area of the first segment into the secondary area of the next segment. The turning spiral is drawn with a tangent to a 30° intercept of the nominal track. Once this is tidied up it only leaves the extreme outer edge of the secondary area to be completed.

A turning spiral is drawn and the outer line of the first segment is extended. A line tangent to the turning spiral is drawn and the whole drawing tidied up.

This is my interpretation of the criteria if anyone has a different interpretation I would be very pleased to hear it. I will put any alternative views on this page so that the procedure specialists can make an informed decision.)

I.W.