VFR vs IFR

[col1948]

I tend to get a problem with an AI VFR flight, in other words some will perform a VFR plan and take off and land as programmed, where as others will get to the approach stage then veer off and carry on flying to nowhere.
If I change the same plan to IFR the aircraft performs perfectly, so IFR always seems to work.
I was reading something about VFR and the weather being VMC and IFR weather being IMC, so I looked it up and found this:
https://www.thebalance.com/definition-v ... imc-282942

Now this got me wondering, if I'm using real world weather will this effect the the way VFR is working in the sim, your thoughts please?

[ahs06]

VFR aircraft will divert in the sim when conditions become IFR. I can only confirm this for FS9 though.

[col1948]

Yes FS9, I can understand the divert if only they diverted to another airport which would be cool in some cases but they don't they fly off forever.

[mikewmac]

Two possibilities immediately come to mind as common sources for your VFR AI problem.

First if you are using Traffic View Board (TVB) to follow your VFR AI, they will enter the downwind leg of the VFR pattern for their destination airport and fly an infinitely long downwind leg without ever turning to the base leg. The workaround for this is to switch your view to another AI until your VFR AI turns to the base leg and then switch your view back to it to follow it turn to final and land. TVB works fine for following IFR AI, but has this one quirk when used to follow VFR AI.

If you are not using TVB, the second possibility is that the VFR pattern altitude for your airport is too high for the VFR AI to turn to the base leg, so the VFR AI flies an infinitely long downwind leg.

Hope this helps.

Mike

[col1948]

Ah! Yes I am using TVB to view, I never knew that, I will give it a try thanks.

[col1948]

Something interest, I set a VFR flight plan with TTools, I went to view the aircraft and had ATC switched on via TVB, when the aircraft announced it's plans it said where it was flying to but then said it was IFR.
I then thought I hadn't done the flight plan properly so went out and checked and it was definitely VFR, so this made me think the weather must have played a part in making it change, I am using Active Sky v6.

So going off my first post that could be why some VFR flights don't land a veer off on approach.

Ignore above, for some reason TTools didn't updtate the flight plan, trying again now sorry Duh!

[clickclickdoh]

FS9 Traffic will absolutely switch to IFR if VFR conditions aren't available. I've never seen them not attempt a landing because of it though. AI traffic is very brave and will attempt to land at an airport without ILS even in the worst conditions.

If you look at the flight plans for the water rescues we did with the US-1 and US-2 in the Iwakuni package, they are all VFR and they keep working even with zero visibility.

When you say that AI traffic is "veering off" do you mean that it is on approach to the runway and turns away and flies off, or that it never makes the turn to final, or is it overflying the runway directly, never lands and climbs straight away to oblivion?

Mike is right about TVB. The same effect can be seen if you fly close formation to a VFR AI plane. They simply won't complete the pattern if there is another aircraft too close to them. It's a very rudimentary separation effect in FS9. The plane simply won't turn to the runway until it is clear of other traffic.

Another thing to consider may be Touch and Go timing. If you have an aircraft flying TNGs and it completes it's designated time, but the next leg doesn't start for a while, it will just wander off into no where. For example, if your flight plan says to do TNGs until 1230, but the return leg is coded for 1245, the plane will wander off until 1245 then start the next leg. Unless you follow it the whole way, it will appear to be a broken flight plan.

[col1948]

Hi, yes it never makes the turn to final, I had a problem a while ago where the aircraft on the ground used to start off then stop, if I pressed the 'Y' key and slewed it would start again.
I was told it was because I was too close or in the way so to speak, but then I was using TVB along with Traffic Tool Box, I stopped using tool box and now just use TVB and I haven't had that problem since.
What I'm leading to is I wonder if there is a way to trck or let the AI think I'm further away than what I am, I have tried the zoom out but that doesn't do anything?

[clickclickdoh]

Give it a shot using Ctrl W or Ctrl Shfit W to scroll through your traffic and see if it makes the turn to final.

This is one of the problems using VFR flightplans, they can be squirrely. That's why I generally only use them where the shorter finals and smaller turns are needed... helicopters and small field operations generally.

[col1948]

Thanks I just did a mikewmac suggested above, I was following with TVB, then as it neared the airfieeld I switched to another AI, when I saw the status of the VFR aircraft on 'Short Final' I switched back to it and sure enough it landed OK.

I did try ther Ctrl W a while ago and it worked to a degree but every now and again I got the same problem with the AI on the ground. but not tried it with an aircraft in flight.

[col1948]

@clickclickdoh, I just tried the Ctrl W and followed not using TVB, it wasn't a long flight but the VFR took off and landed perfect.
Thank you.

Col.

[col1948]

Resurrected this thread, I did what I thought was a simple VFR TNG flight plan, what a pain it was. The aircraft (default Cessna) took off did the circuit then did a TNG, then another and another and another and so on doing endless circuits and it never landed.
I tried various methods, changed to IFR and this time it kept flying to neverland, I went online and copied a few plans but they too didn't work properly, there is definitely something wrong when I try a VFR plan, the IFR plans seem to work better.

I copied a TNG plan from one of the MAIW plans and that seemed to work, the TNG arrival time was 12.30 and the next time was 12.32 but the aircraft had passed that time and it was still flying but it performed OK, so I was puzzled.

I can't understand it, I did lots of these years ago but for some reason I can't seem to get them working properly now.

[clickclickdoh]

Can you post the flightplan here so we can take a look at it.

[col1948]

Hi,
Well I tried various ones but like I say I copied one from an MAIW package and this works, but it's IFR, if I change to VFR I seem to get problems, here it is anyway.

AC#200,G-CESL,20%,24Hr,IFR,09:26:58,TNG09:41:58,010,R,0000,EGNR,09:29:53,09:44:53,010,R,0000,EGNR

This had me puzzled, because the next time after the TNG09:41 is 09.29 but the plan still works, when I change it to a later time I get problems.

[clickclickdoh]

Yeah... I'm surprised that works at all.

You've told it to depart EGNR at 0926 to do TNGs and stop at 0929.. which isn't possible so it goes into what I call "last instruction loop", which is TNGs for ever.

Try changing the 0929 in the second leg to 0944 and the final arrival time to 0959.

Like so:

AC#200,G-CESL,20%,24Hr,IFR,09:26:58,TNG09:41:58,010,R,0000,EGNR,09:44:53,09:59:53,010,R,0000,EGNR

Assuming the taxi from parking and takeoff takes less than 15 minutes that should produce a one or two circuit VFR TNG pattern.

since it's a local VFR TNG patter, the second numbers, 0941 and 0959 don't matter as much since those are used to spawn arrivals not in visual range. So what you are getting now is:

0926: First command to AI, take off, fly to EGNR and do TNGs until next command
0929: Second command, Stop TNGs and fly to EGNR.

The problem is, I bet the airplane isn't off the ground and around the pattern yet in 3 minutes, so the second command is being ignored. The changes I have made should result in:

0926: First Command to AI, take off, fly to EGNR and do TNGs until next command
0944: Second Command, stop TNGs and fly to EGNR.

This gives enough time for the plane to get around the pattern so that it can accept the second command.

[col1948]

Thanks, I've copied a few off the internet with various times, like I said above the IFR seems to work better but for some reason even with the copied plans when changing to VFR I get problems.
I've done some VFR plans and it works, try it again and the next time the AC turns on to base leg then flies off, I think why when it worked last time.

I will try your plan and report back, thank you for your time and help, much appreciated.

[col1948]

Still a problem, I tried the flight plan above and the aircraft turned right and went to 1023ft but there is a hill in it's path and it flew straight in to it, so I changed the altitude in the plan but the aircraft would not climb above 1023ft, I changed it again and still the same problem, is this because it's VFR?

[clickclickdoh]

Yes. As long as it is VFR it will not react to terrain while in the pattern.

You will need to switch to IFR or change runway permissions to make it take off in another direction.

[col1948]

Ah thanks, I guessed that, I have been searching the net for an answer.
The only problem with switching to IFR is the aircraft just does an approach rather than a TNG so to do a TNG I will need to change the weather to blow the other way lol.

[col1948]

Back to the drawing board, I changed the wind direction so it took off the other way towards more flatter ground, it took off, did a 180 turn then flew at 1036ft for nearly 50-60 miles then flew in to some hills.
So the VFR isn't working, it should have turned well before that I'm sure.