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flesland

about RNAV app on SCIE airport

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Hey fellows of avsim PMDG forums, recently I did my first RNAV app on SCIE airport, this APP RNAV is called LODOS1C, so the procedure goes from LODOS, DAKEP until ENTAV at 3500 ft, if you can see in the chart attached below, there is a hold turn to the right at ARTEN, ok, when the times come, once overflying ARTEN the PMDG 737NGX started to make hold turn just the chart shows, so I tought ok, after this hold maybe it will continue to the ARTEN, but this not happen, the plane did another right turn, so the question about this, what´s the right procedure when you must to face a HOLD pattern flying on 737NGX?

 

And in the second hand, If I fly a RNAV app what´s the altitude you must to enter to MCP,  altitude of IAF or the RWY threshold altitude?.

 

STAR RNAV RWY20 

LODOS1C:https://www.aipchile.gob.cl/dasa/aip_chile_con_contenido/aipmap/SCIE/SCIE%20STAR5.pdf

 

Thanks in advance

 

Best regards to all !!!

 

 

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what´s the right procedure when you must to face a HOLD pattern flying on 737NGX?

 

Go to the HOLD page and tell it to exit the hold.

 

 

 


And in the second hand, If I fly a RNAV app what´s the altitude you must to enter to MCP,  altitude of IAF or the RWY threshold altitude?.

 

Depends on your SOP...

 

I use the various step down altitudes, down to the MDA (rounded up), and then set missed upon reaching MDA (or just before dumping the AP to fly the rest of the approach by hand).

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Thanks Kyle, let me see if I understand your advices: If I go to FMC Hold page and I set EXIT HOLD, the plane will exit inmediately or it will end the hold totally, and procede with the next waypoint?.

 

Ok, I think I will use the MDA altitude and then fly by hand, thanks for answers !! (sorry for my english, not native english person).

 

Thansk !!!

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If I go to FMC Hold page and I set EXIT HOLD, the plane will exit inmediately or it will end the hold totally, and procede with the next waypoint?.

 

It will finish the lap and exit upon passing the hold fix.

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When flying a Non-Precision approach (or Non-ILS as they are called now, because LNAV and VNAV can be more precise than the ILS really), I like to set the ALTITUDE bug to the runway threshold elevation rounded UP to the next higher 100th. This way you can use the green arc to assist in final approach.

 

The problem with this is that, if you Go-Around, your Pilot Monotoring (which is you, haha) will have to quickly reset this altitude to the Go-Around altitude.

 

If there's good visibility you can do a "combination" of the two by first using the RWY THLD ELEV, get the green arc to assist you at first and once you're nicely established with the proper V/S on your glidepath and the runway in sight reset it to Go-Around altitude. By this time you can disconnect the A/P and pretty much fly visually.

 

In an ILS approach it's clear: Set your Go-Around altitude in the MCP, no doubt here.

 


 

(or just before dumping the AP to fly the rest of the approach by hand).

 

The problems of flying single-pilot, hehe, no one to yell "reset that altitude bug" to.

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When flying a Non-Precision approach (or Non-ILS as they are called now, because LNAV and VNAV can be more precise than the ILS really)

 

Non-ILS is not the term that is used now. Precision and Non-Precision only deal with the existence or lack of vertical guidance. Relative precision of the technology is not a consideration in precision versus non-precision. That is handled by the decrease in mins, or the decrease in RNP.

 

Please be careful about the information you place here. If you seem like you know what you're talking about then people may take what you're saying as the truth, and in this case, would have an incorrect understanding of precision versus non-precision.

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Kyle, ILS and Precision are not the same, I didn't express myself correctly.

 

What I meant is that usually (some years ago) you'd categorize approaches as "Precision" and "Non-Precision". Precision meaning basically ILS and that's it (I'm not counting MLS cause their use is residual). Today with the advent of RNAV, GPS etc. a "Precision" approach doesn't necessarily have to be an ILS anymore.

 

That's why now you can talk about "Non-Precision" approaches to refer to what in the past would have been "Non-ILS" approaches, because there weren't any "Precision" approaches that were "non-ILS"

 

Guess I have to review some "set theory" :)

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That's why now you can talk about "Non-Precision" approaches to refer to what in the past would have been "Non-ILS" approaches, because there weren't any "Precision" approaches that were "non-ILS"

 

This confuses the topic too much.

 

Precision: Has vertical guidance

Non-Precision: Doesn't have vertical guidance

 

Sure, in the past, the only Precision approach was an ILS, but there's no need to complicate things by creating new terms or adding layers of complexity.

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When flying a Non-Precision approach (or Non-ILS as they are called now, because LNAV and VNAV can be more precise than the ILS really), I like to set the ALTITUDE bug to the runway threshold elevation rounded UP to the next higher 100th. This way you can use the green arc to assist in final approach.

 

Why are you setting the altitude bug below the Decision Altitude ? These approaches to low altitudes in bad weather have the inherent record of accident history because of descent below the minimum descent altitude. Surely the altitude bug set to the runway threshold elevation does not aid you in avoiding a fatal error.

 

Important also to note that an accurate barometric pressure from the tower is desirable to execute the RNP correctly.

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Why are you setting the altitude bug below the Decision Altitude ? These approaches to low altitudes in bad weather have the inherent record of accident history because of descent below the minimum descent altitude. Surely the altitude bug set to the runway threshold elevation does not aid you in avoiding a fatal error.

 

Important also to note that an accurate barometric pressure from the tower is desirable to execute the RNP correctly.

 

It's fine to do it the way I described. Of course, you'll have the BUG on the altimeter set to your MDA.

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I am not sure how setting the BUG to the runway threshold elevation is procedural in any way. You cannot descend that far in IMC. You will have a conflict between the altitude bug on the altimeter tape and the set barometric decision altitude in the PFD and then your minimums annunciations. Best way is to set the DA (it will be reference only because your G/P APP autopilot will be flying the approach, but you need all the help you can get. Reaching the MDA or decision altitude you can set Missed Approach Altitude.

 

I have heard some airlines you set Missed Approach Altitude in the MCP as soon as you reach the FAF, or when G/P is engaged.Sort of like setting the Mised Approach Altitude when you intercept the GlideSlope in an ILS approach.

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I am not sure how setting the BUG to the runway threshold elevation is procedural in any way. You cannot descend that far in IMC. You will have a conflict between the altitude bug on the altimeter tape and the set barometric decision altitude in the PFD and then your minimums annunciations. Best way is to set the DA (it will be reference only because your G/P APP autopilot will be flying the approach, but you need all the help you can get. Reaching the MDA or decision altitude you can set Missed Approach Altitude.

 

I have heard some airlines you set Missed Approach Altitude in the MCP as soon as you reach the FAF, or when G/P is engaged.Sort of like setting the Mised Approach Altitude when you intercept the GlideSlope in an ILS approach.

 

If you have a look in the FCTM there's multiple instances where they recommend the use of the green arc to assist in V/S adjustment and profile control during final approach.

 

If you happen to Go-Around, you'd have to remember to reset the MCP to the Go-Around altitude.

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And in the second hand, If I fly a RNAV app what´s the altitude you must to enter to MCP, altitude of IAF or the RWY threshold altitude?.

 

Assuming that I have LNAV and VNAVPTH engaged in the early stages of the approach, (before FAF), I set the altitude bug to the Decision Altitude+50ft. I do this to ensure that the airplane will not make an intermediate stop at a higher altitute upon reaching it and interrupt the VNAVPTH, then I would need to intervene the altitude to continue the descent. After arming APP in teh MCP at the IAF (FAC and G/P), and upon G/P captured, and the airplane is a few hundred feet below the missed approach altitude,  I set IT, as VNAV will now continue to fly the glidepath regardless of the altitude set in the MCP. If I miss the approach and hit TOGA and engage LNAV and VNAV again, I am now monitoring that the AFDS will capture the set MAA.

 

 


If you have a look in the FCTM there's multiple instances where they recommend the use of the green arc to assist in V/S adjustment and profile control during final approach.

 

 

If you are flying and RNP, why do this ? you cannot fly an RNP with VNAV unless you have a glidepath angle for the approach. So if you have one, vertical guidance is provided without the green arc.

 

Now, if you fly a non precision VORDME, LDA, SDF or other, you can select the vertical profile addon in the MFD and adjust your vertical speed in the MCP so that your projected descent angle matches the altitude constraints in the different fixes.

 

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I'm not a big fan of setting the MCP altitude below MINS... and don't see a reason to do so in the NGX because it has IAN and setting the missed approach altitude once you have captured G/P is standard practice.  The glide path is available, use it.

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