[NO BUG] F18 Carrier TACAN

[Maswi]

Hello together,

 

 

I am not sure whether this is a bug or a feature by INS improvement.

After the last stable patch I once flew again on the carrier. But the Carrier TACAN seems to be off (lateral bias) by some miles.

 

 

The closer you get to the carrier, the less the bias is.

Extreme situation: Land on the carrier and it is correct.

 

 

How to reproduce:

Startup Hornet anywhere (Shore - ALG) or (CV - CV align). Fly to the carrier, set the Tacan, set the BRC and try to find the carrier.

 

 

Expected Result:

You'll be able to find the carrier and intercept the BRC line

 

 

Behaviour:

TACAN position on the HSI has a lateral offset (mostly too far away and on the right side (starboard)). The offset is bigger, the more distance you have to the carrier. As a result of the wrong Tacan position, of course also the needles have a wrong indication, since the position error is high enough to put you on the wrong side.

 

 

 

 

Of course I am waiting until alignment is finished and I have been told that the current indication is wrong and I should at least wait 2 minutes. Now I am unsure if this is a result of a corrupted INS alignment. In case, how would I know when I can switch?

 

 

Further remark: I do not encounter this problem on shore based TACANs so far.

 

 

 

 

Thanks,

Maswi

Edited October 28, 2019 by BIGNEWY

[Maswi]

Track File added:

 

This is a Air Start Situation directly 6 o'clock of the carrier. You can also reproduce it with air start.

 

Immediately you can see on the Right DDI (HSI) that the Tacan Comes in from the Right while flying straight towards the carrier.

 

When overhead, it seems to be fine.

Thanks

Bug.trk

[BIGNEWY]

Hi

 

I can see the issue in your track, however when I try to reproduce in a clean mission all is fine.

 

Your mission has scripts, could I ask you to test with the instant action carrier landing mission, using TCN 74 do you still see the same?

[Maswi]

I will do that this evening.

 

 

You are right I have a script running here.

But I just did it because it was the quickest available mission with airborne start and carrier Tacan set.

 

 

I also experience this behavior in other missions (they also feature scripts, but really simple - completely independent from the one in the .trk file - and should not interfere with the TACAN I guess).

[BIGNEWY]

Let me know how you get on,

 

we would prefer unscripted mission for testing as it rules out any strangeness or can point us to a script problem.

 

thanks

[Swift.]

We had this on a mission, but it only occured because we accidentally had the tacan duplicated between tarawa and stennis

[BIGNEWY]

We had this on a mission, but it only occured because we accidentally had the tacan duplicated between tarawa and stennis

 

Good call swift

 

Yes looks like it could be the issue

 

The carrier group is using 25X and there is a TACAN near Tiblisi using 25X also.

 

try using 74 for the stennis and all should be ok.

[Maswi]

Thanks for that. Could be the issue.

However if that WAS the issue, I'm really wondering if it's correct?

 

 

Tbilsi is a long way to go and you shouldn't be able to pick it up at pattern altitude overhead the carrier?

 

 

But even if you did, I have no idea how the tacan should behave then.

[Maswi]

Can confirm: It is related to channel 25X

[BIGNEWY]

Can confirm: It is related to channel 25X

 

Thanks for confirming Maswi :thumbup: