Where does the final approach segment begin on an ILS approach? It may not be as simple as it sounds to answer. The reason I ask is because I've found some support for at least two answers.
One is that final begins when passing the glide slope intercept point a the last no lower than altitude for the approach. This is the point denoted by the lightning bolt arrow on government charts.
Another answer I've heard is that it begins when glide slope has be intercepted within the limitations of the glide slope and on an approach segment. For the example plate above, this would mean that if the glide slope were intercepted between SILKY and JAKOR the pilot would be considered to be past the final approach fix for all intents and purposes and might even configure the airplane for landing at that point rather than passing JAKOR at the published glide slope intercept.
I think there are valid arguments for both, but I'd apprecate more insight and references on the topic.