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willywonka

Route 2 automatic clearing

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When shutting down the engines, RTE 1 is automatically cleared as expected. But RTE 2 still remains uncleared. Is this correct? I can't find it in the FCOM to verify

 

Also, the ALTNs remained uncleared as well?

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Actually, RTE1 normally "clears" when it reaches end of route. It's more like last line read.. that's all folks.  RTE 2 wasn't active as so it has not cycled to last line yet.

 

You reset your FMS when entering a new INIT POS

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It's more like last line read.. that's all folks.

 

That reminds me of Porky Pig.

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Actually, RTE1 normally "clears" when it reaches end of route. It's more like last line read.. that's all folks.  RTE 2 wasn't active as so it has not cycled to last line yet.

 

You reset your FMS when entering a new INIT POS

But RTE1 can also clear before it reaches end of route. For example, when shutting down normally there's probably some route info left in the FMC, usually from an unused GA segment. Those info get cleared at shut down even though they're not used.

 

You brought up a good point though that RTE2 doesn't get cleared because it's not active. I just can't seem to find references to this behavior in the FCOM to officially confirm it. 

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If you don't want to go through the full re-alignment process (i.e. you're flying a short return sector like DXB-DOH-DXB for example) then use the RTE COPY> option on ACT RTE 1 to 'flush' RTE 2 of any data you don't need for the next sector.

 

Copying the ACT RTE to RTE 2 is also good practice.

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Yes route 2 needs to be flushed manually.

 

I think if you were to activate route 2 in flight (route one will then become the inactive route), then you would have to delete Route 1 later on.

 

You can flush the route by clicking in LSK1R....this downselects the destination into the scratchpad......and then clicking on LSK1L.......this puts the destination in your departure field and then the route is flushed.

 

You can also flush the whole FMC by going to the IDENT page and changing the active date base to the expired one and then back to the current one.

This is something we do before every flight to make sure old wind uploads that were never activated dont fill up the FMC limited memory, making further wind uploads impossible.

I dont know if all this is simulated and modelled correctly in the PMDG though.....just try it.

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Yes route 2 needs to be flushed manually.
Aha, so there it is!

 

It was surprising for me one time to find that RTE2 was still there from a different flight during a preflight. If it went unnoticed and I needed RTE2 later it could have been an interesting "gotcha" moment :rolleyes:

 

 

 


I dont know if all this is simulated and modelled correctly in the PMDG though.....just try it.

 

As far as I'm aware, it is not possible to have more than one database at a time in the PMDG. :mellow:

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Aha, so there it is!

 

It was surprising for me one time to find that RTE2 was still there from a different flight during a preflight. If it went unnoticed and I needed RTE2 later it could have been an interesting "gotcha" moment :rolleyes:

 

Well yes, but as someone mentioned above......if you create a new route (route 1) and then make a route copy, then both route 1 and route 2 will be the same. So the old route will be gone.

 

Making a route copy after having programmed route 1 is part of normal preflight.

As is deleting route 2 from the FMC after the flight.

 

Ofcourse if you forget to both delete the old route 2 after a flight, as well as forgetting to create a route 1 copy during preflight.....then you have made two mistakes, end yes that will give you that gotcha effect if you needed route 2 during flight.

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Interesting... Why would you copy RTE1 to RTE2 during preflight, and how would you use this info? I've only been using RTE2 for ETOPs diversion info.

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Interesting... Why would you copy RTE1 to RTE2 during preflight, and how would you use this info? I've only been using RTE2 for ETOPs diversion info.

Well often during preflight you do not know if you will get Rwy19L or 19R for departure.

You can have both setup and if ATC decides to change the rwy on short notice then all you have to do is change the active route.

 

Same for approach. If both Rwy 11 and Rwy 16 are in use at an airport then you can program them both in advance, check that all the waypoint are jn there, that all altitude and speed restriction are correct, that the missed approach is programmed correctly, etc.

things get quite stressy if you have to do all that on short notice!

 

Furter more, you often get ATC shortcuts. I like it to be able to still see how my original route was.

 

Also for flights over high terrain or ETOPS sections you would set mental (or planned in case of ETOPS) descision point along you route at which you go to alternate A or B.

For example Atlantic crossing westbound; first back to EINN untill descion point1 and ahead to BIKF after it. And back to BIKF untill dp2 and then ahead to CYHZ.

Or over Afghanistan Eastbound.....very high terrain.......in case of rapid decompression; back to UTAA until point VUVEN and ahead to OPLA after VUVEN.

 

The problem is that there is no back on route 1 :-(

Route 1 goes back a few miles....but then nothing.

Kinda sucks to have nothing while in a stress situation trying to go back along your original airway!

If you made a route copy during preflight, then at least you can still follow this blue line back (in TCK SEL mode) untill you have time to deal with programming the FMS for your diversion back to your enroute alternate.

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Well often during preflight you do not know if you will get Rwy19L or 19R for departure.

You can have both setup and if ATC decides to change the rwy on short notice then all you have to do is change the active route.

 

Same for approach. If both Rwy 11 and Rwy 16 are in use at an airport then you can program them both in advance, check that all the waypoint are jn there, that all altitude and speed restriction are correct, that the missed approach is programmed correctly, etc.

things get quite stressy if you have to do all that on short notice!

 

Furter more, you often get ATC shortcuts. I like it to be able to still see how my original route was.

 

Also for flights over high terrain or ETOPS sections you would set mental (or planned in case of ETOPS) descision point along you route at which you go to alternate A or B.

For example Atlantic crossing westbound; first back to EINN untill descion point1 and ahead to BIKF after it. And back to BIKF untill dp2 and then ahead to CYHZ.

Or over Afghanistan Eastbound.....very high terrain.......in case of rapid decompression; back to UTAA until point VUVEN and ahead to OPLA after VUVEN.

 

The problem is that there is no back on route 1 :-(

Route 1 goes back a few miles....but then nothing.

Kinda sucks to have nothing while in a stress situation trying to go back along your original airway!

If you made a route copy during preflight, then at least you can still follow this blue line back (in TCK SEL mode) untill you have time to deal with programming the FMS for your diversion back to your enroute alternate.

 

WOW! Thank you very much for this great amount of RW knowledge! ^_^

 

I read your post some hours ago during a lunch break. It is really good to know how useful RTE2 actually is.

 

Great and BIG THX! B)

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Thanks for the insights, Rob. It's always fun to learn from people that drive these things everyday. B) Now I will have more to keep busy with during a cruise even when not in ETOPS. :lol:

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Very intresting topic. My thanks both to OP and Rob. This brings up another issue I´ve found lately and which I can´t find in the manuals.I hope Preston is ok with the wuick hijack since his issue has already been solved.

 

I haven´t been able to start RTE 2 form scratch whilst airborne. In other words, while flying an active RTE1 I cannot enter a departure and destination airport on RTE2, like I can on the ground. The only way I cant get something to load on RTE2 is if I copy RTE1 to RTE2. Is this common behavior? 

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Thanks for the insights, Rob. It's always fun to learn from people that drive these things everyday. B) Now I will have more to keep busy with during a cruise even when not in ETOPS. :lol:

You are very welcome :-)

 

I got one more Route 2 Trick, see below.

WOW! Thank you very much for this great amount of RW knowledge! ^_^

 

I read your post some hours ago during a lunch break. It is really good to know how useful RTE2 actually is.

 

Great and BIG THX! B)

Ditto :-)

 

 

The trick below may not help us as much in the PMDG777 as in some of the real life 777s that are still flying around with old FMC software.

The PMDG777 can draw huge circles (green) around points you entered in the fix page. FMC with older software can only draw circles up to 511nm, and with large ETOPS sections it is not immediately visible in which direction your enroute alternate is (left or right). So someone came up with a trick involving Route2 :-)

 

What you do need for this trick are ETPs...Equal Time Points....between each enroute ETOPS alternate.

I am not sure if modern FSX flightplanners spit out ETPs as coordinates like in real life?

If not then you will have to calculate or estimate those coordinates yourself (taking the winds into account)

 

 

N1buJ.jpg

 

What you see above is the Capt Route2 (left CDU), the ND, and the FO Route 2 (right CDU).

 

I have created triangles, formed by the blue dotted lines, that immediately show in what direction (left in this case) you divert to your closed planned enroute alternate. At my current position, if something happens I would turn left to CYYR.

The Capt CDU shows what our Route2 looks like. It is a copy of Route1...so exactly the same.

The FO CDU shows how you program the points required to form those triangles.

 

The next pic shows a similar triangle....just further down the route (halfway across the Atlantic)

 

YTCEu.jpg

 

Again it is immediately clear where your enroute alternate is.

Before N52W036 you are still in the CYYR triangle so you turn back (and to the left).

After N52W036 you are inside the BIKF triangle and thus you turn left to BIKF.

After N53W023 you are outside the BIKF triangle and thus EIDW or EINN is closer (timewise.....dont forget about winds!).

 

 

If you want to try this then the trick is to add a waypoint to the end of your ROUTE2 LEGS page that is NOT in your flight plan (because we are going to delete it again later)

I use waypoint AAA.

 

Note:all changes are made on the inactive Route!.....you are not allowed to change anything in the active Route (in my case Route 1 was still the active route) because if you enter the wrong coordinates you will get off track....not good in a non radar environment.....plus adding points on the active route would also screw up automatic position reporting via datalink)

 

As you can see on the first pic my original ROUTE2 copy ended in VENEN.

- I then added AAA after VENEN in the LEGs Route2 page.

- next I added the first point along my route where I would divert to CYYR. (To get exact coordinates for this point I entered CYYR in the Fix page and created a 390nm circle (390nm=my max non ETOPS diversion distance) and then I pressed the LSK abeam this 390nm entry to copy the intersection coordinates of the green 390nm circle and my Route to my scratchpad)

- I added these coordinates after AAA and the FMC then renamed the coordinates to CYY03.

- Then I added CYYR

- Then N5226.0W03641.0 (these are the exaxt coordinates of the ETP between CYYR and BIKF as calculated by the flightplanner software.....I hope FSX flightplanning tools can calculate these points as well....as far as I know they are required to be on an  ETOPS flight plan!) The FMC renamed these coordinates to N52W036

-Next I added BIKF

- And last but not least, I added the BIKF-EIDW ETP coordinates (N5306.0W02328.0) which were renamed by the FMC to N53W023. (EIDW was the last ETOPS alternate for this flight....I could have added EIDW to the Route2 LEGs page as well, but since it was allmost straight ahead it would not have formed a nice triangle.....besides, once passing N53W023 you are close enough to Ireland to see EIDW on the MAP.....no need for a triangle).

 

And now you can (and should) delete that AAA point we added.

You will then end up with a route discontinuity between VENEN (or whatever the last point on your Route2 was) and CYY03.

The good thing about that route discontinuity is that the blue line from VENEN all the way back to CYY03 is then erased  :-)

 

So you end up with:

. nice triangles that clearly show the different enroute alternate sections

- no disturbing/confusing line from end of route to AAA

- ROUTE2 is not interrupted or tampered with anywhere at all so it can still be activated....all you need to do is delete those points you added at the end.

(ofcource a new route copy of ROUTE1 will copy Route1 as it is (so without all the waypoints you have already passed and will also get rid of all that stuff we added at the end).

 

 

Good luck puzzeling ;-)

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Good luck puzzeling ;-)

 

Thank you very much again Rob for this great RW insights. ^_^  I (and I think we all) really appreciate it!

 

I will try to follow the ETP/ALTN/LEG2 programming procedure on one of the next weekends.

 

I started this week (by chance) a kind of short hop world trip which took me from Tallin to Shanghai until now (via Kyiv, Moscow, Novosibirsk, Irkutsk, Ulaanbaatar, Bejing). Hong Kong, Kuala Lumpur/Singapore, Brisbane and Auckland will follow.

Later the flights to Tahiti and Hawaii are definitely a case of 180min ETOPS in combination with a limited choice of ALTN. So some nice additional route depictions for those decisions on the NDs will be good companions while over the water... :blink:

 

Again many thanks for keeping FS such an interesting hooby for us "wannabes"... B)

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BTW, PFPX will calculate ETPs. Or for a freeware option, SimBrief does it too.

I am still with FSC9. So PFPX will be next...

BTW:

I read that most T7s have ETOPS 330 since 2011 already and that there are restrictions in the southern Pacific area. Probably due to missing sea traffic?

Anyway: if ETOPS=330 THEN "Engines Turning Or Passengers Swim" gets closer, statistically...

A350 is aimed to be ETOPS 420 IIRC. I personally don't like the thought of being over the pole with one engine roaring to keep GS400 to the next APT.

What do you think?

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Me?

 

I dont like long ETOPS sectors either, who does?

Much nicer to have a suitable alternate every 1/2 hour if you ask me.

 

But there is no need to keep full trottle to stay at 400kt Groundspeed or whatever.

Those times and distances are preflight requirements only....rules and regulations to create a legal flight plan, that is all.

 

Once you are in flight you can go where ever you think is best.

You dont have to go to the alternate airport planned on your flight plan either.

Dont get me wrong, those planned alternates are preferable because dispatch has checked them for everything (open/nav aids/weather/performance (landing distance/go around climb performance)/ATC available etc etc) but sometimes you cant go there because weather changed for the worse and then you have to check all those things for the airport of your choice.

 

Safest course of action should be taken to land at the nearest suitable airport.

That could mean reducing thrust a bit and flying slower than those speeds you mentioned......it can mean that you will fly longer than those three hours before you reach your alternate too!

On a non ETOPS flight you can even decide to divert to an enroute alternate that is outside the ETOPS range if it is the safest course of action!

All legal as long as you can give good reasons for your actions.

 

Pre flight planning requirements are one thing.....but in flight you are the captain and you do what you think is best/safest under the current conditions ;-)

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