approach modes

[Driver170 42]

ok i'll try make sense of this guys

 

my flight was from EGPH to EICK in ireland

 

STAR, RNAV approach VAPAL1G 

 

ILS+DME 35

 

It was a disaster since commencing my descent i kept getting des path unachievable. i was way high at the end of the star i was in vnav and lnav all the way down. why is this i thought vnav was meant to get you down on the path. anyway i approach rwy 35 before turning right i tried to press vor/loc but it wouldn't arm i then tried app wouldn't arm so i just left it in vnav and lnav why was this? so i turn finals still in vnav and lnav and FAC plus G/P appear i have never seen this before? is this some sort of vnav approach mode or something? 

[Driver170 42]

The chart from navigraph was an ILS+DME and LOC+DME

 

just don't get it, it says ILS why didn't it do a normal ILS app

[LarsW 1]

Hej, did you definitely have the altitude in your MCP window reduced right down to the alt of the final approach fix?

 

because a sure fire way to end up still high on a VNAV descent is to forget to reset the MCP alt - the VNAV cannot override this, so the alt must be set or the plane does not descend; and then gives the 'descent path unachievable'.

[Vargveum 53]

Difficult to say without seeing what you did or didn't do.... Basic stuff, but: Strong tailwind? Did you input the descent winds on CDU DES page? Did you tune the ILS frequency?

[rfresh737 36]

G/P (Glide Path) will appear when you are too far out on the ILS to pick up a good glide slope signal. In those cases, instead of pressing APP, you must press VOR/LOC to capture the LOCalizer only. I have one such an approach I make going into Las Vegas airport. I intercept the localizer 25 miles out for crying out loud (I'm flying the published STAR). That's way too far out to pick up the G/S signal so I press VOR/LOC and capture the localizer.

 

Then when I'm about 10 to 15 miles out AND the glide slope pointer is filled in, I press APP and now G/S appears in the FMA and then I know it's now armed to capture.

>just don't get it, it says ILS why didn't it do a normal ILS app?

 

There are a lot of manual things you must do when flying an autopilot flown ILS approach.

[Vargveum 53]

 

 

G/P (Glide Path) will appear when you are too far out on the ILS to pick up a good glide slope signal. In those cases, instead of pressing APP, you must press VOR/LOC to capture the LOCalizer only. I have one such an approach I make going into Las Vegas airport. I intercept the localizer 25 miles out for crying out loud (I'm flying the published STAR). That's way too far out to pick up the G/S signal so I press VOR/LOC and capture the localizer.

 

very good point. Missed the G/P part in there. 

[rfresh737 36]

>very good point. Missed the G/P part in there.

 

That was a minor part of it. He had initial descent trouble with that "des path unachievable" CDU mesaage.

 

Vernon: what does "ILS+DME 35" mean? Does that mean you were 35 miles out on the approach?

[Driver170 42]

Hej, did you definitely have the altitude in your MCP window reduced right down to the alt of the final approach fix?

 

because a sure fire way to end up still high on a VNAV descent is to forget to reset the MCP alt - the VNAV cannot override this, so the alt must be set or the plane does not descend; and then gives the 'descent path unachievable'.

Had it set all the way down to 3000 the FAF

G/P (Glide Path) will appear when you are too far out on the ILS to pick up a good glide slope signal. In those cases, instead of pressing APP, you must press VOR/LOC to capture the LOCalizer only. I have one such an approach I make going into Las Vegas airport. I intercept the localizer 25 miles out for crying out loud (I'm flying the published STAR). That's way too far out to pick up the G/S signal so I press VOR/LOC and capture the localizer.

 

Then when I'm about 10 to 15 miles out AND the glide slope pointer is filled in, I press APP and now G/S appears in the FMA and then I know it's now armed to capture.

>just don't get it, it says ILS why didn't it do a normal ILS app?[/color

 

There are a lot of manual things you must do when flying an autopilot flown ILS approach.

 

Thats what i've been doing in most of my app well all of them, untill i done this one which it didn't let me engage LOCalizer or the APP buttons!

 

Instead it held in Vnav and Lnav all the way down and FAC appeared plus G/P

>very good point. Missed the G/P part in there.

 

That was a minor part of it. He had initial descent trouble with that "des path unachievable" CDU mesaage.

 

Vernon: what does "ILS+DME 35" mean? Does that mean you were 35 miles out on the approach?

ILS+DME runway 35

Difficult to say without seeing what you did or didn't do.... Basic stuff, but: Strong tailwind? Did you input the descent winds on CDU DES page? Did you tune the ILS frequency?

I had a calm tailwind?

 

No des winds put in not sure what alt to select in that page?

[Vargveum 53]

I had a calm tailwind?

 

No des winds put in not sure what alt to select in that page?

 

A strong tailwind will make the aircraft overshoot the profile if you do not enter the winds into the FMC. Remember: sh**t in, sh**t out. That's how computers work

 

As for finding the forecast winds at different levels, you can use realworld weather charts ( http://aviationweather.gov/iffdp/fdwndc ) or a planning software like PFPX. 

 

Hope this helps. 

 

PS: A note about the wind charts if you are unfamiliar with them. The numbers around the map isn't the wind in knots but rather the air temperature at the given FL. The wind speed is indicated by the barbs. 

 

One barb: 10 knots

 

One half barb: 5 knots

 

Solid triangular barb: 50 knots

[rfresh737 36]

I got setup for this approach to try and see if I could shoot this ILS. On the ILS plate CORK runway 35 the freq is 109.15 but the sim doesn't seem to recognize that. I get no localizer and no glide slope data at all. Same problem Vernon had, so I was able to reproduce it at least.

 

Is there something that has to be configured in FSx or the 737NFX to make the ILS freq work?

 

Thanks...

[Mike777 163]

 

 

The chart from navigraph was an ILS+DME and LOC+DME

just don't get it, it says ILS why didn't it do a normal ILS app

 

Posted Today, 10:38 PM

I got setup for this approach to try and see if I could shoot this ILS. On the ILS plate CORK runway 35 the freq is 109.15 but the sim doesn't seem to recognize that. I get no localizer and no glide slope data at all. Same problem Vernon had, so I was able to reproduce it at least.



Is there something that has to be configured in FSx or the 737NFX to make the ILS freq work?

 

Posted Today, 10:38 PM

I got setup for this approach to try and see if I could shoot this ILS. On the ILS plate CORK runway 35 the freq is 109.15 but the sim doesn't seem to recognize that. I get no localizer and no glide slope data at all. Same problem Vernon had, so I was able to reproduce it at least.



Is there something that has to be configured in FSx or the 737NFX to make the ILS freq work?

 

Hi, Vernon and Ralph,

 

Not at my FS computer right now, but problem might be that the FS stock airport has old ILS frequencies.  Take a look in the FS map and see what frequencies are showing up there.  This would partially explain both your issues.

 

Mike

[rfresh737 36]

Hi Mike

 

Where in FS would we find that? FS Map?

 

Thanks...

[Mike777 163]

 

 

Where in FS would we find that? FS Map?

 

From inside an FSX flight, up at the top, World>Map.  You click on the airport in the map and a window with the various frequencies should pop up.  You may have to zoom in.

 

Mike

[rfresh737 36]

I zoomed in but I cannot see any ILS freq.

[Mike777 163]

I just checked FSX.  On the map, it is showing 109.9 for both runways 17 and 35.  Set an NGX down at the 35 threshold, tuned 109.9 & LOC/GS lit up as they should.  Nothing for 109.15 (I found a chart showing 109.15 is the correct frequency for 35, as you said).

 

Mike

I zoomed in but I cannot see any ILS freq.

 

Hi, Ralph,

 

You need to click on the airport map.  A window should open showing "Airport Cork" and "VOR Cork."  You want to click on "Airport Cork" and a list of frequencies for the airport will show up.

 

Mike