The relation between runways and SIDs/STARs

[WebMaximus 372]

When I'm picking a runway on the arrivals page in the FMC the available STARs are automatically filtered only showing me STARs connected to the selected runway. However when picking a runway for departure during preflight the same is not true for SIDs but instead all of them are displayed ragardless what runway I've chosen for departure.

 

Is this the same way it's working in the real NG that only STARs but not SIDs are filtered depending on what runway you've selected?

[scandinavian13 5,192]

 

 

Is this the same way it's working in the real NG that only STARs but not SIDs are filtered depending on what runway you've selected?

 

It filters on the departure side, too. You must just be seeing SIDs that aren't dependent on runways. As an example, all of the SIDs at IAD are for all runways. The ZILLI SID out of LAX, though, would only be available if you selected one of the 26s or 27s.

 

Additionally, it's all in how the nav data provider parses the data, as well (this could be FAA-level parsing, though). The GIBBZ STAR into IAD is lists GIBBZ2.19L, GIBBZ2.19C, and GIBBZ2.19R, but the instructions are the exact same for all of them. So they appear runway-dependent, when they aren't (fully anyway, the instructions only change when you select a 1L/C/R versus a 19L/C/R).

[WebMaximus 372]

OK, got it - thanks!

[scandinavian13 5,192]

OK, got it - thanks!

 

Welcome - good question!

[mgh 89]

The chart for BUNZZ TWO departure at IAD has 7 routes. How are they distinguished  for navigation purposes and by an FMC?

 

TAKEOFF RUNWAY 30: Climb heading 301^o to 820, then turn left to LOULU...

 

[scandinavian13 5,192]

The chart for BUNZZ TWO departure at IAD has 7 routes. How are they distinguished  for navigation purposes and by an FMC?

 

The selection of the runway automatically selects the appropriate "route" for the BUNZZ departure.

 

EDIT: You'll note that the CDU EXEC light doesn't light up until a runway is selected, because selecting one is required for this SID.

[mgh 89]

I understand. But it means then when the runway is selected the FMC then selects one of the 7 routes. Therefore the FMC must be capable of distinguishing between the routes in its database - BUNZZ TWO 1, 2, 3....?.

[scandinavian13 5,192]

 

 

Therefore the FMC must be capable of distinguishing between the routes in its database - BUNZZ TWO 1, 2, 3....?.

 

This is very much the case, but I'm not understanding where you're going.

 

I've already answered that the NG FMC will auto-filter the available SID/STAR options when a runway is selected, if they're runway dependent. This is simulated in the NGX.

 

If you're getting at the fact that you have to select the various GIBBZ options, that's simply a matter of how the navdata is parsed. I'm not sure if that's the FAA's doing, or navigraph's, but it's inconsistent throughout the country. Moreover, you would not want to select a specific runway until the type of approach is actually assigned (which is usually during the STAR), which is why it's listed as GIBBZ2.19L on the left while still allowing you select a different approach/runway on the right. Ideally, it would be GIBBZ2.19 (or somehow indicating the 19s in general), which would make it more obvious that you'd select the approach later.

 

In a similar manner, the HYPER STAR has been drastically changed (between 4 and 5) such that ATC instructions are usually "fly the HYPER5, Runway 1R transition [...]," even though you might actually land on 1C, or 1L. As such, it would be listed as HYPER5.1R on the left while still allowing a different runway to be selected on the right.

[mgh 89]

How are the routes identified from ATC to an aircraft before take-off -   the charts don't show that?

 

For example,  at EGLL there are SID charts that show more than routes but they are all uniquely identified. The Compton SID has 4 routes but they are uniquely identied -  CPT 3F ,CPT 3G,  CPT 5J , and CPT 4K,

[scandinavian13 5,192]

 

 

How are the routes identified from ATC to an aircraft before take-off -   the charts don't show that?

 

...by telling them what runway to use...?

 

I'm not sure how unique identification on a chart is going to make anything any clearer than clearing an aircraft to depart a specific runway, and follow the specific path that's already been charted, unique identifier on a chart or not.

 

If it makes you feel better, you're welcome to write BUNZZ2A, BUNZZ2B, BUNZZ2C, BUNZZ2D, BUNZZ2E, BUNZZ2F, and BUNZZ2G if it helps you separate all of them. As far as the radar controllers go, though, it's pretty easy to figure out "oh hey, there's an aircraft that just came off of Runway 30 - he'll be following the charted path off of 30..."