Single-Leg Flight Plans

gadgets · 31 Mar 2009

For some time, at the request of several users, AI Flight Planner has allowed entry and compilation of single leg flight plans - presumbly to allow an AI to take-off and return immediately. AIFP generates a traffic file for such flight plans essentially identical to that generated by TrafficDatabaseToolbox - essentially identical because AIFP's time precision is minutes so there are sometimes minor differences (seconds) in departure and arrival times. This includes the single-leg flight plan example in the TDB SDK.

However, I have never been successful in getting either AIFP's or TDB's traffic files to generate AI traffic. Add a second leg and they work just fine, but not with a single leg. This includes the single-leg flight plan example in the TDB SDK.

If any of you have had success with single-leg flight plans (as opposed to two leg flight plans using a single airport), would you please send me sample flight plan and traffic files so I can make this aspect of AIFP work.

Thanks in advance,
Don

jvile · 1 Apr 2009

This is a FP where the AI Plane takes off and immediately lands

AC#31104,N1NAVY,10%,4h,IFR,00:00:00,00:15:00,70,F,0001,KJAX,01:47:00,02:02:00,70,F,0001,KJAX

There is no such thing as a single leg FP. There are no single leg FP examples in the traffic toolbox SDK. All FP's must have 2 legs. You could say that my example is 2 single FP's but it requires 2 for the AI Plane to fly the first single FP.

In my example I have 2 single leg FP combined into a single string

The TDBB does exactly the same thing. You can generate a single leg FP but there must always be 2 in order for the AI Plane to takeoff.

C172-1,N172SP,33,TWO_HOURS,VFR

{0010,KEUG,12,,0030
0100,KEUG,12,,0130}

Limitations
Schedules for the TrafficDatabaseBuilder must contain at least two entries. The last example in the above table shows a schedule for a Cessna doing touch and go landings for 20 minutes in the first hour (the difference between the circuit end time of 0030 and start time of 0010), and for 30 minutes in the second hour, repeating every two hours.

A single leg FP using TDBB is understood to be a TNG. We trick the AI Engine in my example to make the AI Engine force the AI Plane to land and stay on the ground. BUT the AI Plane must takeoff and land 2 times within the repeat time specified.

Q: Is it possible to assign an aircraft to only fly from airport A to airport B instead of a round trip?

The simple answer is NO!!!! This also applies to airport A to airport A. Airport A to A must occur twice within the repeat time as specified.

MS/ACES Answer to the question is

A: No. One of the design goals of the AI traffic system was that aircraft should not appear or disappear suddenly while in view. To meet that requirement, all routes must be round-trip so that the aircraft's position in the world can be accounted for at all times.

Airport A to Airport A is a round trip when executed 2 times within the repeat period.

gadgets · 1 Apr 2009

There are no single leg FP examples in the traffic toolbox SDK.

Jim, I beg to differ. The final example in the FS9 SDK file "CustomRoutes.dat" is:

# Aircraft type: C172-1
# Tail number: N172SP
# Traffic density: 33%
# Repeats every: hour
# Flight rules: VFR
# Schedule:
# Time Departure Destination Altitude FlightNumber Circuits?
# 0010Z KEUG KEUG 12 (none) until 0045Z
C172-1,N172SP,33,ONE_HOUR,VFR
{
0010,KEUG,12,,0045
}

which compiles in TDB without error.

I do note, however, that in the FSX SDK, that example has been changed by adding a second leg. That's the example you show in your post.

As well, you may recall a lengthy series of posts early on in this forum (to which you were a contributor) in which another renowned member of this community gave several examples of single-leg FPs that he said "worked perfectly". It was that post that geve me the incentive finally to pursue this. (Incidentally, that individual confirmed to me earlier this week that, in fact, his statement was not accurate.)

I will now (un)modify AIFP to generate an error message if only a single leg is specified.

Thanks for your input.

Don

jvile · 2 Apr 2009

Don

You can compile a lot of FP's and nothing shows up. Just because a 1/2 of FP compiles does not mean it is a single leg FP.

It is understood that a FP compiled with a single airport is TNG FP and it will compile. However as you have admitted nothing will fly until you create a second leg. At that point it is no longer a single leg FP but a round trip FP.

C172-1,N172SP,33,ONE_HOUR,VFR
{
0010,KEUG,12,,0045
}

The above is not what the SDK shows and you tampered with the removal of 1/2 leg and then say that is a single leg FP. All FP's start out as a single leg but what good is it if nothing will take off.

You can beg to differ all you want but if you are going to show what the SDK says then quote the SDK in its entirety. Don't delete lines and then call something a single leg FP.

TTools could have very easily seperated a 2 leg string into a header with 2 lines like the TDBB does but that does not make it a single leg FP since both legs are always required. Flight Plans are made up of a string of single leg FP's but it takes 2 legs minimum to make the AI Plane fly.

AC#31104
N1NAVY
10%
4h
IFR
00:00:00,00:15:00,70,F,0001,KJAX
01:47:00,02:02:00,70,F,0001,KJAX

As well, you may recall a lengthy series of posts early on in this forum (to which you were a contributor) in which another renowned member of this community gave several examples of single-leg FP's that he said "worked perfectly".

I remember many of the post and others that think you can do something that you cannot. There are a lot of renowned developers that lack how something works and study only the visual aspects of FS9/FSX and never decipher the actual code.

gadgets · 2 Apr 2009

The above is not what the SDK shows and you tampered with the removal of 1/2 leg and then say that is a single leg FP.

Jim, that statement alleges I am a liar and a fraud! If you had bothered to check, you'd have found that my quote from the SDK is complete, accurate and factually presented. (I downloaded the SDK from MS this morning to ensure that I hadn't inadvertently changed it.)

For some time, I've "bit my tongue" and put up with your intolerent and "shoot from the hip" responses to my (and others') posts in various forums - because you are one of the more knowledgeable people on the internal workings of FlightSim. While your communication style often left a lot to be desired, I would search for the "nuggets" often buried among the diatribe and ignore the rest. This time you've gone too far.

As moderator of this forum, I don't believe I or the other participants should have to tolerate such unwarranted abuse. I will be deleting this entire thread in 48 hours. Unless you can be more respectful, please take your opinions elsewhere!

Don

n4gix · 2 Apr 2009

Don, I've verified the accuracy of your example in the FS9 SDK's final entry of CustomRoutes.dat file. You did indeed quote it accurately.

That said however, simply being in the SDK doesn't guarantee that the example will actually work. I can cite many, many other errors in the various SDKs MS/ACES released over the past decades... :rotfl:

Code:

# Aircraft type:   C172-1
# Tail number:     N172SP
# Traffic density: 33%
# Repeats every:   hour
# Flight rules:    VFR
# Schedule:
# Time   Departure  Destination  Altitude  FlightNumber  Circuits?
# 0010Z  KEUG       KEUG         12        (none)        until 0045Z
C172-1,N172SP,33,ONE_HOUR,VFR
{
    0010,KEUG,12,,0045
}

Since I really know nothing much about the subject, I feel I can be completely neutral in this matter. Reading the extremely skimpy documentation, I noticed this in the Q&A:

A: All routes are round-trip, so the departure location is the same as the previous arrival location. Also, the departure location of the first leg is the same as the arrival location of the last leg.

This implies to me that when compiled even this single leg "plan" should result in what amounts to as a "round trip" from KEUG to KEUG...

...if it does not -in fact- work properly, then all that proves is that the devs at ACES never really understood their own code... :duck:

gadgets · 2 Apr 2009

Thanks, Bill.

This implies to me that when compiled even this single leg "plan" should result in what amounts to as a "round trip" from KEUG to KEUG...

I had similar suspicions. I had confirmed that the TDB compiler did not generate a workable traffic file from single-leg FPs. But, in light of other statements, including one in an earlier post by a very-knowledgeable individual that they [single-leg FPs] "worked perfectly" (now retracted) - which seemed to be reinforced by the SDK, I was concerned that while the TDB compiler didn't produce useable code, perhaps some other compiler did. My goal was to clarify the matter and fix AI Flight Planner so that it would correctly process single-leg FPs if, in fact, single-leg FPs did work - a feat I had been unable to accomplish.

I think we can safely conclude that single-leg FP's don't work.

Don

jvile · 2 Apr 2009

gadgets said:
Jim, that statement alleges I am a liar and a fraud! If you had bothered to check, you'd have found that my quote from the SDK is complete, accurate and factually presented. (I downloaded the SDK from MS this morning to ensure that I hadn't inadvertently changed it.)

For some time, I've "bit my tongue" and put up with your intolerent and "shoot from the hip" responses to my (and others') posts in various forums - because you are one of the more knowledgeable people on the internal workings of FlightSim. While your communication style often left a lot to be desired, I would search for the "nuggets" often buried among the diatribe and ignore the rest. This time you've gone too far.

As moderator of this forum, I don't believe I or the other participants should have to tolerate such unwarranted abuse. I will be deleting this entire thread in 48 hours. Unless you can be more respectful, please take your opinions elsewhere!

Don

I have not alleged that you are a liar and a fraud. I am simply pointing out what the most current Traffic Data Base Builder SDK shows. You are looking at a old SDK and yet trying to adapt it today standards. Since you are a developer I would think you would be using the most currect SDK for the TDBB.

There are 9 SDK versions of the TDBB. I assumed you would be reading the lastest version. The TDBB is not new and came into existance on 11/24/2001. Since then it has been updated to reflect the most precise wording. Each version added or changed the wording and examples used so everyone would understand what is allowed and what is not allowed.

Versions of the TDBB SDK are as follows

11/29/2001
03/14/2002
09/12/2003
03/04/2004
04/03/2004
06/09/2006
09/26/2007
04/24/2008

You are looking at the version that is 4 years old dated 04/03/2004 which has a incomplete example from the customRoutes.dat and only showing 1/2 of a round trip leg.

That misprint that you say is correct was fix with the TDBB SDK on 06/09/2006. Each version of the TDBB since 11/29/2001 is no different then what we now have dated 04/24/2008. One change took place in 03/04/04 at that was the additional TNG added which requires 2 legs for the same airport.

For some time, I've "bit my tongue" and put up with your intolerent and "shoot from the hip" responses to my (and others') posts in various forums -

If you do not like my responses then say so. If others do not like my responses in post in various forums it is up to them to say so.

As moderator of this forum, I don't believe I or the other participants should have to tolerate such unwarranted abuse. I will be deleting this entire thread in 48 hours. Unless you can be more respectful, please take your opinions elsewhere!

Forums are a form of communication to help others in understanding what the facts are. If you post something that is not correct are we suppose to just sit idle and let incorrect information flow out into the FS world.

There are other forum sites that dictate what can be said, lock post, delete post that some moderator does not like because someone disagrees with them and I have never seen that here at FSdeveloper.

The developers here pride themselfs in helping others when opinions start to surface. If you view my post as opinions then please show me the factual side of FS rather then threaten to delete responses I made to your post. I am always first to admit I am wrong about something.

As I have already stated my post assumed that you had researched the TDBB SDK's since the original release on 11/29/01 and up to the most current which is dated 04/24/08. If I had known you were going to base what you say on a 4 year old SDK pertaining to the TDBB my answer would have been slightly different.

However that still does not change the fact that in the last 3 TDBB SDK's released the examples of a single leg TNG FP was corrected to show both legs. The TDBB compiler is not FS version specific and has been with us for 8 years.

jvile · 2 Apr 2009

Since I really know nothing much about the subject, I feel I can be completely neutral in this matter. Reading the extremely skimpy documentation, I noticed this in the Q&A:

A: All routes are round-trip, so the departure location is the same as the previous arrival location. Also, the departure location of the first leg is the same as the arrival location of the last leg

This implies to me that when compiled even this single leg "plan" should result in what amounts to as a "round trip" from KEUG to KEUG...

...if it does not -in fact- work properly, then all that proves is that the devs at ACES never really understood their own code...

Hi Bill

All routes are round trip but from KEUG to KEUG is only a single leg and must be completed as a round trip with 1 more additional leg from KEUG to KEUG.

ACES when updating all the wording for the SDK's would say the correct words and show correct examples in some versions and then leave out a very important line in another version of the SDK. If you look at the last SDK printed which is bundled with the SP2 SDK the wording is correct and the lines of code show what a round trip looks like for TNG's.

n4gix · 3 Apr 2009

jvile said:
Hi Bill

All routes are round trip but from KEUG to KEUG is only a single leg and must be completed as a round trip with 1 more additional leg from KEUG to KEUG.

ACES when updating all the wording for the SDK's would say the correct words and show correct examples in some versions and then leave out a very important line in another version of the SDK. If you look at the last SDK printed which is bundled with the SP2 SDK the wording is correct and the lines of code show what a round trip looks like for TNG's.

I had not thought to look at the FSX SDK, as I thought the discussion involved FS9's version of AI traffic...

It is obvious to me that Don was quoting the example from the same FS9 SDK (03/04/2004) as I referenced, so when you stated the following in your post, you were -in fact- calling Don's integrity into question...

The above is not what the SDK shows and you tampered with the removal of 1/2 leg and then say that is a single leg FP.

(note: emphasis mine)

...as though Don were attempting to "prove his point" dishonestly.

Frankly I don't blame Don one bit for feeling as though someone had kicked him in the privates... :scratchch

It may well have not been your intention to do so, but there it lies like a stinky pile of poop, nonetheless. :tapedshut

Perhaps it's not too late to make amends and move forward again as friends... :whiteflag

Bill

arno · 3 Apr 2009

Hi guys,

This discussion goes a bit over my head, as this is not my area of expertise at all. But please keep it friendly

.

On forums like this sometimes the intonation of a post is lost, which can cause negative feelings for other users. Most of the time this is not what the poster meant at all. So please stay friendly to each other, we don't want to have a flame war here.

In the few cases that we get such discussions here some admin or moderator will lock the thread. But normally we won't delete any thread. That is against my principles that this side should collect knowledge useful to others.

So please keep it nice here, in the end everybody is trying to help each other.

jvile · 3 Apr 2009

Don

My choice of words when I said 'you tampered with the removal of' was not the best way to express what I was seeing in your post. That I apologize for.

I did not see anything in your original post that said you were looking at one of the older SDK's. I should not assumed that you and I were looking at the latest written TDBB SDK and I thought you were removing one of the single legs to try and force the AI plane to appear. Again I apologize for my assumptions and wording of my post.

gadgets · 3 Apr 2009

I accept your apology, Jim, but not without a lecture.

This was the third forum in about as many days in which you had responded to me in a less-than friendly manner. Because someone disagrees with you, or takes a position that you disagree with or makes a statement that you doubt, doesn't make them wrong. New ideas, including those that address concerns about old ways, are what keeps this hobby vital. You are entitled to your opinion, but you are not God!

When responding to a post, you really should take the time to read it first and try to infer the poster's intent. It should have been clear from the beginning that:

I was aware that two legs were generally required;
in response to the claims of others, I had made a serious attempt to make single-leg FPs work but was unsuccessful and so was seeking information on how they'd done it; and
I had reviewed and used the SDK.

Admittedly, I did not indicate that the excerpt I posted was from the FS9 SDK. But, in my response to your first post, I clearly did so and acknowledged that the FSX SDK was different. That didn't seem to deter you.

From our long-standing "relationship" and past communications, I think even you would agree that I've got a pretty good "handle" on AI operation in FlightSim. My request was reasonable. It was not frivilous. It wasn't even addressd to you. Nonetheless, I would have welcomed a simple "Nope. Won't work." from you. But instead, you attacked - not once, but twice - calling my integrity into question each time.

If you do not like my responses then say so.

Is that clear enough?

Jim, you could make so much more of a contribution if you worked a little on your "bedside manner".

End of lecture.

I hope we can now get on with enjoying our hobby. In deference to Arno who indicated that deleting this thread as I had originally stated I would do would be inappropriate, I am simply closing it.

Don

Single-Leg Flight Plans

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