Originally Posted by
Jetalc
Sorry, Tony - maybe it's me, but it seems like you're talking in circles, and saying, in a different way, what I already stated. In your first two examples, the published GS int altitude is the same, regardless of where the GS is intercepted. It is the PUBLISHED altitude that counts. You repeated what I had already said. In both cases (int at 4000 and int at 3000), the spot over the ground that is considered the FAF is the same. That is a point that can be found to have the same lat/long, GPS fix, whatever.
According to the Pilot/Controller Glossary:
"FINAL APPROACH FIX- The fix from which the final approach (IFR) to an airport is executed and which identifies the beginning of the final approach segment. It is designated on Government charts by the Maltese Cross symbol for nonprecision approaches and the lightning bolt symbol for precision approaches; or when ATC directs a lower-than-published glideslope/path intercept altitude, it is the resultant actual point of the glideslope/path intercept. I believe that's what I already said.
It's not a suprise that communication is difficult when the terms used are so imprecise. We are close, I believe, to understanding the same thing. Indeed, in scenarios #1 and #2, the Final Approach Segment begins at the same geographical point, and we could measure the coordinates of that point. But that's beside the point.
Originally Posted by
Jetalc
A fix, according to the FAA, is simply a generic term "used to define a predetermined geographical position used for route definition. A fix may be a ground-based NAVAID, a waypoint or defined by reference to one or more radio NAVAIDs." Perhaps you have issue with the use of the FAA's word "Fix" in "Final Approach Fix," since the geographical position isn't always the same?
Now we're getting somewhere. Since the point at which the Final Approach Segment is NOT predetermined, since it is affected by the altitude at which the airplane intercepts the glideslope, there can be no point published and labeled as the Final Approach Fix. Clearly, the geographical point at which the airplane in Scenario #3 commenced the Final Approach Segment was much different than the point in #1 and #2. Which was predetermined?
Originally Posted by
Jetalc
Not sure what you mean by "On final." You could be aligned with the runway centerline, heading toward the runway, and not even be on the Final Approach Segment (since the intermediate segment ends at the FAF, by definition). Do you mean "at the FAF?"
By "on final" I mean established on the Final Approach Segment. For a Non-Precision Approach, that would be on course inside the FAF. For a Precision Approach, that would be on course, on glidepath, at or below the published glide-slope intercept altitude. We haven't mentioned Jepps in this discussion, yet, but for Jepps users, that means "in the feather."
Originally Posted by
Jetalc
You state: "In fact, there could be an infinite number of points at which the Final Approach could be commenced on a precision approach - - but not a single Final Approach Fix. Not a Maltese Cross, not a lightning bolt, and not an arrow." Well, I agree with you, but that's NOT what we're talking about. We're talking about the definition of a FAF, not where you believe you're "turnin' onto final." Big difference.
"turnin' onto final" <-- trying to put words in my mouth. I don't approach this subject cavalierly, and I don't have to believe. The transition from the Intermediate Approach Segment to the Final Approach Segment is well-defined, and it does not depend on a predetermined geographical position. I submit, therefore, that any use of the word FIX with this transition is a misnomer at best, lazy at worst.
Originally Posted by
Jetalc
The FAA uses the word "Final Approach Fix" in many instances, and not unintentionally:
"(2) Glide Slope Critical Area. Vehicles and aircraft are not authorized in the area when an arriving aircraft is between the ILS final approach fix and the airport unless the aircraft has reported the airport in sight and is circling or side stepping to land on a runway other than the ILS runway. "
"The primary ILS approaches for Los Angeles are attached for reference. Both contain an abundance of “slow-down-while-going-down,” but the 25 ILS is arguably worse, because the speed brakes can be deployed on the 24 approach, and some attempt can be made to play catch up before the precision final approach fix (PFAF). "
"The final approach fix is generally situated anywhere from 3˝ to 5 miles from the runway threshold. The pilot will normally prepare the aircraft so that it is configured and ready to fly a stabilized descent by the time the aircraft intercepts the glideslope."
There isn't enough room here to post the thousands of times the FAA uses the word "ILS Final Approach Fix."
If it is the word "fix" you have a problem with, maybe you can coerce the FAA into changing it. However, stating (erroneously) that there is no FAF on a precision approach is misleading at best. Arrogant and ignorant at worst, and I'm not sure which category you fall into, since I don't know you.
Like I said - - misnomer at best, lazy at worst.
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