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FS2004 IFR vs. VFR selection in FP editor

gadgets

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ca-britishcolumbia
After all that and you are not going to investigate whether there's any effect other than the potentially false indication?

Don
 
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unitedstates
After all that and you are not going to investigate whether there's any effect other than the potentially false indication?

Don
No actually not. I need to wrap my brain around this a bit more to see how I want to proceed next. I just didn't want to seem ungrateful for everyone's help by not at least acknowledging where things were left off-- even if I haven't exactly found any answer. So I thought a summation was in order. Sorry if it was taken that after everyone's help, I was just giving up.

Clearly I crossed two issues-- The issue of the plane not landing on the runway I wanted it to at KSMX, and the issue of the IFR labeling of certain legs, but not others; even though I had set the entire flight plan to VFR.

I believe I have solved at least 1/2 of the issue of the runway landing and what priority is established at KSMX... depending upon ILS's and approaches. But that's not for this post, and I intend to continue that discussion in a new post when I'm ready. Probably this weekend.

As for the IFR labeling, yes, there are other things I want to try. I want to reverse the order of the legs in the flight plans and put them in different parts of the daytime. Put them on different days. Make a flight plan with only two legs... KCCR to KSMX and back again... make it a VFR, and see what the label then says. If I isolate variables and then test, do I get different results?

So no, I'm done yet. I was just tired and needed sleep.

I'll let you know what I come up with if I suddenly see that leg that was saying IFR go VFR in a VFR FP. But if I have no luck, then I might not know what else to say. I'm by far no expert at this.

-- John
 
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unitedstates
Don & Jim, (and/or others):

I'm happy to report that after 2 months of sleeping on this and also combing through multiple variables to see what I could come up with, I finally found the "magic bullet" that alters the (IFR) (VFR) moniker on the AI aircraft labels. And it was actually a lot simpler than I thought. I completely overlooked the most obvious thing, and what threw me were the somewhat unrealistic flight levels I had set high and low (all over the board) for each leg. All the while, never realizing that somewhere there's a threshold flight level that strictly divides IFR from VFR status. It took some experimenting to find it, but it's a line drawn between FL 180 and FL 181.

To be more specific, let me display a quick 4 square matrix to illustrate my point:

Flight_Plan_Flight_Level_Matrix.png


So long as the global flight rules setting (in the upper right hand corner of the AIFP edit window) is set to IFR, all legs will be IFR regardless of the flight level set for each individual leg. This is because global IFR status trumps everything else-- as in these two edit windows below:
FP_v3_IFR_FL180.png

FP_v4_IFR_FL181.png


However, if one selects the VFR global flight rules setting in the AIFP edit window, this now opens up the possibility to subdivide flight rules type between the two-- for each individual leg within the flight plan-- depending upon whether the leg has a flight level 180 and below (VFR), or 181 and above (IFR).

If all the FL's are at or below 180, VFR status will prevail:
FP_v1_VFR_FL180.png


The plane will go through its day with all legs labeled (VFR):
v1_VFR_FL180_results.png



However, if all the FL's are at or above 181, IFR status will prevail (even though it's globally set to VFR):
FP_v2_VFR_FL181.png


The plane will go through its day with all legs labeled (IFR):
v2_VFR_FL181_results.png


The conditions to yield the change were not that complex, they just weren't easy to spot. Where I went wrong was that I set my flight levels for each leg at such random levels, I would have never spotted a pattern based upon threshold-- as seen in this first test sample from late December:

When globally changed to VFR, my 4th, 7th, and 8th legs were the only ones stuck as IFR legs simply because of their altitudes over 18,000'. And it took me nearly two months to spot this.
FP_v0_IFR_variable.png


The levels were all over the map where I had no due regard for flight above or below 18,000 feet-- nor did I think it would make a difference when I went to change the global flight plan from IFR to VFR.
My original intent was to only run this flight plan as a global IFR. It was only after I noticed some runway selection inconsistencies at KSMX (Santa Maria, CA), that I tried changing the FP to global VFR, and as an unintended consequence, discovered the inconsistency with the flight rules label. Which is what started this whole post back on New Year's Day in the first place. I believe this now sufficiently closes the case.

Finally, I had inadvertently tied KSMX ILS issues into this post. I want to eventually address my findings there as well, but will address them separately, in a few weeks, in a new thread.

I hope this has been helpful to some, and proof that despite my long absence from the thread, I did not give up in finding the answer.

-- John
 

scruffyduck

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Do a Google on Transition Altitude. E.g. http://en.wikipedia.org/wiki/Flight_level#Transition_altitude. 18,000 (FL180) is the transition altitude in the US. Other countries have different transition altitudes. Above this altitude altimeters are set to a standard barometric pressure of 29.92 Below that you need to set your altimeter to the local barometric pressure as advised by ATC or other weather services.

You can also Google the altitude restrictions associated with Visual Flight Rules. The main one is that planes flying under VFR must be in clear air and cannot be in cloud. I am sure that are some ultimate restrictions on VFR altitude as well which will depend on airspace restrictions, clearances and so on.
 
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John

I am glad you where finally able to solve the mystery. I never saw the pattern either but I tested your findings and found them to be accurate.

I would like to add that most flyers are under the assumption that all flights in the USA must be IFR if the flight level is above FL180. Your findings also show that Microsoft coded FS using the same assumption which is, any flight above FL180 is a IFR flight regardless of the global FP or individual leg.

If Microsoft had read the FAA regulations it says VFR flights are allowed up to FL290 ft in the USA and that is what they should have used to divide IFR from VFR.
From the FAA Airman's Information Manual, Chapter 3 (Airspace)...

Section 3-1-5. VFR Cruising Altitudes and Flight

See TBL 3-1-2 at the bottom of the document.
https://www.faa.gov/air_traffic/publications/atpubs/aim/aim0301.html

There is another regulation that says I can fly VFR all the way up to FL600 ft (Class A airpace) in certain situations.
 
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167
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unitedstates
Do a Google on Transition Altitude. E.g. http://en.wikipedia.org/wiki/Flight_level#Transition_altitude. 18,000 (FL180) is the transition altitude in the US. Other countries have different transition altitudes. Above this altitude altimeters are set to a standard barometric pressure of 29.92 Below that you need to set your altimeter to the local barometric pressure as advised by ATC or other weather services.

You can also Google the altitude restrictions associated with Visual Flight Rules. The main one is that planes flying under VFR must be in clear air and cannot be in cloud. I am sure that are some ultimate restrictions on VFR altitude as well which will depend on airspace restrictions, clearances and so on.
Jon,

Yes... I was aware of 18,000 feet as being a major dividing line in that regard, and I appreciate your references to that regard. The "great" revelation in this case-- as it related to my post-- was that I had no idea how AI traffic for FS9 and AIFP programming handled VFR vs. IFR inputs... and the FL 180 cut off did not seem overly obvious... or at least overlooked by me personally.

Incidentally, since you did respond to this, I do have an additional question for you.

If 18,000' feet is the official transition alt in the U.S.; then in my experimentation, shouldn't the cutoff threshold I discovered (on a global VFR input) have been a line between FL 179 and FL 180... AND NOT a line between FL 180 and FL 181? It seems to me that 18,000' should already be past the threshold as should everything from 18,001 through 18,099 and into 18,100. Only everything from 17,999 and down should be below the threshold. At least in my mind. So that's another reason, in my experiment my findings were not overly obvious or to necessarily be expected.

-- John
 
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