reported No Fuel, EPU kicks in, Attitude Director Indicator bugged

[Papa Saubär]

Hello gentlemen,
 

Today we had a long A2A training. We noticed the following behavior, as soon as the EPU (no fuel) kicks in, the items listed below are bugged. As you can see in the screenshot the Attitude Director Indicator is completely wrong. I am flying almost straight here and it shows me a very strong bank.
 

Before I ran out of fuel, I made a sharp turn. In addition, the Attitude Bars are also completely wrong in the HUD.
 

Trackfile I can not upload, because of the file size. But I'm sure that you can easily reproduce that.

 

Bugged items:
- Attitude Director Indicator
- Attitude Bars
- EGI Magnetic Heading
 

Spoiler

 

 

Edited March 3, 2021 by Papa Saubär

[dorianR666]

ive seen this too.

running on EPU messes up lots of things. but only sometimes.

Edited March 6, 2021 by dorianR666

[dorianR666]

track attached, but showing different symptoms than OP - tadpole stopped working. im switching steerpoints but tadpole is always within velocity vector.

 

f16_epu_tadpole.trk

[dorianR666]

another track attached, showing some of the symptoms OP mentioned.

 

in particular, HUD attitude ladder and attitude director indicator are messed up. notice that i moved EPU switch from Norm to On, and waited for the green light indicating EPU is running. only after that, i shut down the engine. still, even tho EPU was already running the whole time and thus electricity source was never lost, INS and ADI both got messed up.

 

f16_epu_ins.trk

Edited March 6, 2021 by dorianR666

[BIGNEWY]

With a no fuel state with EPU online various systems on the AC and DC bus will fail.

 

 

 

 

[dorianR666]

1 hour ago, BIGNEWY said:

With a no fuel state with EPU online various systems on the AC and DC bus will fail.

 

 

 

 

That cant possibly explain why tadpole doesnt work.

 

Neither can it explain why ADI fails if EPU was already running before main generator loss. If ADI was one of the "various systems on the AC and DC bus will fail", then it shouldnt be running at all after main generator failure, yet it is, so that cant be the explanation. The problem here is that it appears that power is lost to components like ADI and INS for a fraction of a second and then regained again. Which would be understandable if EPU switch was at Norm, since it takes a while for it to engage - but this still happens with EPU already engaged before the generator loss! See my third post.

 

Please review this again.

Edited March 8, 2021 by dorianR666

[BIGNEWY]

2 minutes ago, dorianR666 said:

Please review this again.

 

The thread is still marked investigating.

[Bouli306]

On 3/8/2021 at 7:13 PM, dorianR666 said:

That cant possibly explain why tadpole doesnt work.

 

Neither can it explain why ADI fails if EPU was already running before main generator loss. If ADI was one of the "various systems on the AC and DC bus will fail", then it shouldnt be running at all after main generator failure, yet it is, so that cant be the explanation. The problem here is that it appears that power is lost to components like ADI and INS for a fraction of a second and then regained again. Which would be understandable if EPU switch was at Norm, since it takes a while for it to engage - but this still happens with EPU already engaged before the generator loss! See my third post.

 

Please review this again.

 

Even when the EPU is started before Gen failure it will produce a power cycle when the Gen fails. That power cycle might put off your INS and therefore all related indicators. Mind you in my experience with the F-16AM/BM it rarely happens. But than again it is not a F-16AM/BM that is simulated.

[Machalot]

7 hours ago, Bouli306 said:

Even when the EPU is started before Gen failure it will produce a power cycle when the Gen fails. That power cycle might put off your INS and therefore all related indicators. Mind you in my experience with the F-16AM/BM it rarely happens. But than again it is not a F-16AM/BM that is simulated.

Are you saying IRL there is a power cycle, and it is modeled correctly in DCS?

[Bouli306]

Yes, there will be a power cycle. The only thing is that it may or may not screw up INS alignment. 

[Machalot]

1 minute ago, Bouli306 said:

Yes, there will be a power cycle. The only thing is that it may or may not screw up INS alignment. 

Seems like a pretty obvious thing you'd want to keep continuity for. Why is it unable to do a power change over without interrupting power like many other vehicles and systems? 

[SpaceMonkey037]

When switching from main gen power to EPU gen power, it is pretty much the same as quickly moving a power plug from one socket to another. In the F-16 this has a big chance of messing up the INS because it doesn't get any power. Thankfully, the engineers though of this and gave the INS a battery. iirc the battery lasts for about 10 seconds, enough for a power change. The battery uses a good 10-15 ish hours to recharge mid-flight. In dcs as of now it does not seem like our INS has a battery modelled. Overall there are so many flaws in the emergency systems in our F-16 that I don't really see the point in "bug fixing" these things. The best thing ED can do is to halt progression of all other F-16 systems and just focus on emergency systems, because you really do need all the emergency systems. Only having a few doens't make much sense. It's like parachuting, it doesn't help to have a correctly modelled string to open the parachute, if you don't even the parachute modelled. 

I hope ED understands this problem, and that they take the correct approach when resolving it. All in all I honestly think that emergency systems shouldn't be a prioritisation right now, it's way more important to have the base aircraft working. However, once you have a good base aircraft modelled I think developing the emergency systems should be a priority.
However, most of the community will probably dislike this way of developing the aircraft as most people only seem to care for weapon system development. Simply because of what systems the community wants, we will probably see ED putting emergency systems at the bottom of the prioritisation list, sadly.
Safe flights.

[Machalot]

13 hours ago, SpaceMonkey037 said:

When switching from main gen power to EPU gen power, it is pretty much the same as quickly moving a power plug from one socket to another. In the F-16 this has a big chance of messing up the INS because it doesn't get any power. Thankfully, the engineers though of this and gave the INS a battery. iirc the battery lasts for about 10 seconds, enough for a power change. The battery uses a good 10-15 ish hours to recharge mid-flight. In dcs as of now it does not seem like our INS has a battery modelled.

This is what I was getting at.  There are many aerospace systems that have the ability to seamlessly switch power sources without an interruption.  I would expect the F-16 to be the same.  Looks like it's just not modeled yet.

[Bouli306]

As said in real life the INS gets screwed sometimes.. battery or not... Even without INS there are ways to land and find your way: Wingman, ATC, VFR etc. I just think it is not a very big deal. It is all about priorities set by the OEM. By the way, as far as I know the block modelled has a standby generator. So the chances of getting a running EPU are very slim. And running yourself out of fuel is just stupid.

 

I am one of those people that thinks priority should be flight model, avionics and weapon system.. as the last part handling emergencies or damage.

[BIGNEWY]

I have reported to the team for better investigation, it is a low priority issue. 

 

Best option is not to run out of fuel at the moment

 

thanks