president:
Thanks for the reference. I quote the pertinent language:
An aircraft can either self position for an approach or be vectored. Before leaving the Initial Approach Altitude (also known as Platform Altitude) the aircraft must be lined up with the runway and at an appropriate distance. If the aircraft is not in the correct position the final descent can not be commenced as the aircraft may be outside of the protected area, hence terrain separation can not be assured. A descent at this point would be dangerous, particularly if in Instrument Meteorological Conditions.
I am not sure what the author is trying to say. In any case, it would nave no application in FAA controlled airspace. We learned the lesson the hard way with the TWA 514 CFIT. Those AIM cites above, are almost verbatim quotes of federal aviation regulations written after TWA 514.