BOAC, this is NOT a RNAV approach. It's a NDB approach constructed in accordance with PANS OPS 4 as shown in the left bottom corner. If it was overlay the title would be GPS or NDB approach. Once you've realized that, and rightfully pointed out deficiencies, you simply fly it raw data and use the FN point to commence your 3 degree descent towards the minimum instead of dive and drive. The title of the procedure states clearly what it is and how it must be flown.
