Glide Slope...

#4

On a non-precision approach, the maltese cross indicates the final approach fix. Glide slope interception on a precision approach (ILS) is considered to be the FAF and is indicated by the lightning bolt.
Last edited by Tinpusher007; 11-05-2006 at 04:54 AM. Reason: Incorrect information
#5

No.
No.
A precision appraoch does not have a Final Approach Fix, per se, and the Maltese Cross has no relevance to the precision approach. It depicts the FAF for the non-precision approach.
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A precision appraoch does not have a Final Approach Fix, per se, and the Maltese Cross has no relevance to the precision approach. It depicts the FAF for the non-precision approach.
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#6
Line Holder
Joined APC: May 2006
Position: EMB-145
Posts: 61

The final approach fix for a precision approach is glide slope interception which is indicated by the lightning bolt lookin thing. This occurs right before the maltese cross which is the FAF for a non precision approach. AIM Chapter 1
#7

Of course a precision approach has a FAF - otherwise how would you be able to comply with the reg that addresses visibility dropping below what is required for the approach (i.e., outside the FAF, at or beyond the FAF)?
#8

The Final Approach Segment for a precision approach begins where the glideslope intercept altitude coincides with the center of the glideslope. There is no defined "point" where this occurs, no Final Approach Fix.
Glideslope Intercept altitude is depicted with a lightning bolt by some AIP providers (NOS, NOAA) and not others (Jeppesen, LIDO).
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#10

I disagree with the first part, Tony. The FAF on a precision approach is at the published glideslope intercept altitude. It will never be higher, but it may be lower, if, for example, ATC has you holding at the OM at an altitude lower than the GS Int altitude and they clear you for the approach out of the hold...
Of course a precision approach has a FAF - otherwise how would you be able to comply with the reg that addresses visibility dropping below what is required for the approach (i.e., outside the FAF, at or beyond the FAF)?
I just pulled up the ILS to Rwy 18R at MEM as a "random" example. (If this link doesn't work, go to Fltplan.com and navigate to MEM, and the ILS 18R http://204.108.4.16/d-tpp/0611/00253I18R.PDF )
The glideslope intercept altitude is 3000'. The FAF crossing altitude on glideslope is 1876'. Consider 3 scenarios. In each scenario, ATC clears the pilot for the ILS. When is he established on the Final Approach Segment? In scenario 1 he is vectored at 4000'. In Scenario 2, he is vectored at 3000'. In Scenario 3, he is vectored at 2000'.
In scenario 1, he maintains 4000' until intercepting the glideslope, and then begins down. On Final? No. Not until he passes the glideslope intercept altitude at 3000'.
In scenario 2, he maintains 3000' until intercepting the glideslope, and then begins down. On Final? Yes. And, it's at the same point over the ground as in scenario 1.
In scenario 3, he maintains 2000'. About 3.3 miles prior to intercepting the glideslope, he passes the same point on the ground where the airplanes in Scenarios 1 and 2 began their final appraoch segments. Is he then on the final approach segment? No. It is not until he intercepts the glideslope at HIS altitude that he is on the Final Approach Segment.
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.
BROKE CFI - - Where in AIM Chapter 1?
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