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  1. #1
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    FAP/FAF Question/Comment

    I have heard some say a FAF does not exist on a precision approach according to ICAO, and that it is technically a FAP. While, most of the ICAO documents lead to believe that is true I have found one particular statement that makes me think otherwise (ICAO-8168):

    1.2.2.2 The approach segments begin and end at designated fixes. However, under some circumstances certain of
    the segments may begin at specified points where no fixes are available. For example, the final approach segment of a
    precision approach may start where the intermediate flight altitude intersects the nominal glide path (the final approach
    point).
    Note.— See Chapters 2 to 6 of this section for detailed specifications on approach segments.


    Notice it says "MAY start at a FAP" that leads me to believe it MAY not, and thus starts at a FAF.

    In addition the FAA, and I know the FAA can be different, clearly defines in the pilot controller glossary a FAF as the point at which the final approach segment begins, and is indicated by a multese cross (NPA) or a lighting bold (precision approach). Therefore the FAA indicates a FAF (by a lighting bolt) on a PA.

    Some may argue that a Final Approach FIX on a precision approach is not a FIX, that is why it does not exist on a PA. However, the definition of a Fix according to the FAA is a geographic point of reference with regard to visual aid, NAVAID, or another navigation device. The glide slope and the intermediate approach altitude DOES exist at a geographic point defined by "another navigation aid." Thus the Point at which an aircraft intercepts the minimum glide slope intercept altitude, IS a FAP AND According the the FAA is also a FAF.

    Now my question is, how accurate is my analysis, and can anyone shed any additional light onto this topic.

  2. #2
    Roddy_Piper's Avatar
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    Re: FAP/FAF Question/Comment

    whoa...way to deep for starters.

    i think the bottom line is that on a precision approach it is a FAP, because depending on how u fly the approach you could intercept the glidepath at a different point above ground everytime. therefore, it couldn't be a FAF, since a FAF is a defined point above the ground (wherever that may be for that approach).

    so...u fly two consecutive ILS approaches and intercept the glidepath at 5.2 from the runway and 5.3 from the runway. those are two different and legal beginnings to your precision approach. if there was a FAF on that approach then one, or both, of those approaches are bunk. the FLIPS cannot anticipate where every pilot on every ILS will intercept the glidepath. that's why there's a lightning bolt depicting the FAP...which is basically where you intercept the glidepath at your intercept altitude.

    hope i made sense...u could be 100% correct and i'm just blabbering. again though, WAY TOO DEEP brandon. begs the question, does it matter?

  3. #3
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    Re: FAP/FAF Question/Comment

    I know its a bit "does it really matter" but I like to understand the small things as much as I can lol.

    As for a FAF being a defined point and a precision approach doesn't have a defined point...it does have a defined point, and can not differ on the same approach. The defined point is where the intermediate approach segment intercepts the minimum glide slope intercept altitude, that can only occur at one particular point, and it need not be a named point. For example look at this approach:

    http://www.myairplane.com/databases/.../00651IL16.PDF

    Although the lightning bold exists at a different point than the cross, and the lightning bolt does not have a name, according to the FAA it still meets the requirements for the FAF: It is where the final approach segment begins on the precision approach, it is also a FIX according to the FAA, it is a geographic point in reference to another navigational aid. It can only occur once over the surface of the earth.

    As for the lighting bolt, according to the FAA's definition, it defines the FAF not the FAP:

    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.


    EDIT: by the way, I am not disputing that the FAP does exist, it does exist, however according to the FAA's definition it is called a FAF. The FAA defines FAP as when a NPA does not have a FAF.

    Again, I know its a "does it really matter?", but to me it does :-) Just want to understand some of the
    intricacies.

  4. #4
    Roddy_Piper's Avatar
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    Re: FAP/FAF Question/Comment

    alright lets see. the X on the approach u explained is the FAF for the LOC RWY 16, which is a non-precision approach. the lightning BOLT is the FAF for the ILS, which is the precision approach. there is both an X and a lightning bolt because that particular approach is 2 approaches on one plate. the X corresponds to the non-precision approach and the lightning bolt corresponds to the precision approach.

    u can't really use those two FAF's interchangeably. the OR in the ILS or LOC RWY 16 denotes two separate approaches on the one plate.

    also gee whiz stuff but if u see a plate that says something like: RNAV (GPS) RWY 2, the words in the (), in this case the "GPS" is not spoken when talking about the approach. this would be the RNAV RWY 2 approach when spoken.

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