ILS Approach Question

C

cptndavis

New Member
Hi Folks..

Perhaps someone could help me. I am confused about the presentation of an ILS approach on NOAA charts.

Take the ILS RWY 8 to PHX for example

http://flightaware.com/resources/airport/PHX/IAP/ILS+OR+LOC+RWY+08/pdf

As I have learned the lightning bolt represents the FAF. It is my understanding that this is where you would begin your descent on the glide slope when flying the precision portion of the approach. Looking at the the PHX approach, there appears to be numerous lightning bolts, some as far as 22 miles out from the runway threshold. SARTE, HIKID, & ILIKE all have the bolt as well as minimum altitudes to be flown for the particular segment. So what gives?

Assuming I am cleared for the approach, does this mean as soon as I pick up the glideslope I can start down from any one of those fixes?? Or am I supposed to descend lower and lower following the plan view altitudes and eventually reach WAZUP intersection to intercept the glideslope at 3000?

I'm not sure and would appreciate any feedback to help me understand this..

Thanks to all..

Mike
 
lightning bolts are just fancy lines conecting names to fixes. the faf is marked by the maltes (spelling:insane:)cross on the profile view.

You can start down the glideslope when you intercept it, however, never below the minimum altitude published on the approach, in this case that is 3000'. Frequently glideslope intercept occurs just slightly before the FAF.
 
tgrayson said:
No, that's the FAF for the LOC (non-precision) approach. The FAF on the ILS is glideslope intercept at the published intermediate altitude.
Click to expand...

Which happens to be the lightning bolt in the profile view.

The above poster is correct in saying the lightning bolts in the plan view are just indicating the location of intersections. You wont normally see this unless the approach has DME step down points
 
Maurus said:
Which happens to be the lightning bolt in the profile view...The above poster is correct in saying the lightning bolts in the plan view are just indicating the location of intersections.
Click to expand...

Both of which I pointed out in the post prior to his.
 
Thanks to all for the feedback. Just to confirm, if cleared for this approach from one of the outlying DME fixes, I would descend according to the altitudes listed in the plan view until reaching 3000, at which point I would maintain that altitude until intercepting the glideslope?
 
cptndavis said:
Thanks to all for the feedback. Just to confirm, if cleared for this approach from one of the outlying DME fixes, I would descend according to the altitudes listed in the plan view until reaching 3000, at which point I would maintain that altitude until intercepting the glideslope?
Click to expand...

That would be the classic way to handle it, yes.

However, many pilots will choose to intercept the GS further out and descend on the glide slope, which is fine as long as you ensure the GS will clear the step down altitudes. The GS isn't primary for altitude until the FAF.
 
The profile view indicates a lightning bolt, which is GS intercept altitude. I would maintain this until established to ensure receiving false GS indications.
 
tgrayson said:
No, that's the FAF for the LOC (non-precision) approach. The FAF on the ILS is glideslope intercept at the published intermediate altitude.
Click to expand...


I stand corrected. I should have done an IMSAFE to post checklist and made the decision to go to be instead.
 
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