Sign in to follow this  
luscombeguy

Quirk in ILS approaches

Recommended Posts

Whenever I put a ILS approach into the FMC it always shows the last two waypoints on the approach at the same altitude. On the approach plate the altitudes would be(for instance) 9000-7000, but in the FMS it always shows the lower altitude for both. Any ideas?

 

 

 

            

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

 

 


Any ideas?

 

Examples, please.

 

There are way too many ILS approaches in the world to simply say "always" with no proof.  My bet would be the navdata, but I could be wrong...

Share this post


Link to post
Share on other sites

Kyle, it happens with every ILS approach I try. The most recent example was ILS 35L at KDEN and before that the ILS 25L at KPHX. I have the latest navdata from Navigraph. It didn't just start, but has been that way for the last year.

Share this post


Link to post
Share on other sites

 

 


It didn't just start, but has been that way for the last year.

 

If it was working before and then its behavior changed, then it's highly likely that it's a nav data issue (regardless of how long it's been doing it).

 

Additionally, the first two altitudes on the 25L approach into KPHX are supposed to be the same

...and why are you shooting an ILS into PHX anyway??? haha.  Weather doesn't exist there, unless you consider heat to be weather.  Clouds???  What are clouds?  And trees for that matter?

 

The altitudes should be different on the KDEN approach, but I'm curious to see a picture of the FMC to see what it's showing versus what's on the chart, specifically.

Share this post


Link to post
Share on other sites

Here is the FMS setup for the 35L ILS into KDEN. Also, I live in Tucson and if we have more than 1/4 cloud cover we shoot CATII approaches. :P Actually even if I'm going to land visually I usually put a ILS approach in for backup.

Share this post


Link to post
Share on other sites

 

 


Here is the FMS setup for the 35L ILS into KDEN.

 

Thanks.  First - this probably isn't related to the issue, but it drives me up a wall, so I'll point it out - there should be a discontinuity between FQM and CELBI.  The STAR is not meant to transition onto the approaches.  Leave the DISCO in there.  You'd get vectors from (before) FQM onto the various approaches.

 

As far as the numbers, can you please show me how you selected it on the DEP/ARR page?  My bet is that if you didn't select anything else other than the approach (no transitions/extensions), it's simply adding CELBI there because DYMON is the FAF.  It's just there to intercept the line prior to the FAF (a controller has to put you 2NM outside of the FAF when using vectors).  I'm guessing if you select the CRUUP option, the altitudes would indicate correctly.


 

 


Also, I live in Tucson and if we have more than 1/4 cloud cover we shoot CATII approaches. Actually even if I'm going to land visually I usually put a ILS approach in for backup.

 

CAT-II has more to do with ceiling than it does cloud cover.  You could have overcast at FL250 (typical of PHX fall/winter) and you wouldn't be shooting CAT-anything..  And I was really just taking a shot at Phoenix in general, just for fun.  It's actually a good practice to have the ILS there as a backup, even when visual.

Share this post


Link to post
Share on other sites

If I am flying on Vatsim I do leave the DISCO in, if not on Vatsim or if no controllers on I just "self vector". I selected the 35L ILS approach and the Larks7 STAR with the ALS transition in that order. Could that be the problem, choosing the approach first ? I was just joking about the CATII approach, KTUS doesn't even have a CAT approach,or ever need one. :P

Share this post


Link to post
Share on other sites

 

 


Could that be the problem, choosing the approach first ?

 

Shouldn't be.  Careful with the terms, though.  I was talking about an approach transition and not a STAR transition.  When you select an approach, it gives you the option to leave it as initially selected (where the FMC assumed vectors to the FAF), or select another transition/extension fix (different initial fixes, as appropriate).  My bet is that it's just how it handles the vectors to FAF issue.  If you're getting vectors to the FAF (selecting the approach without any other fix selection), then you're not responsible for hitting the other fix altitudes.

 

Haha - sorry I missed the joke!  Got it now!

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this