can not reproduce LGP CCRP not working after land/rearm

[TheTrooper]

Hi, don't know if anyone else has come across this. I dropped some JDAMs then went beck to refuel and rearm but with 2000lbs laser guided bombs. My vertical aiming line was way off to the right of the the target so they were useless. No cue coming down. I did a normal INS alignment so that has nothing to do withit.

Alsoartificial horizon completely off after a dodgy landing and can't seem to reset it. 

[WHOGX5]

1 hour ago, TheTrooper said:

Hi, don't know if anyone else has come across this. I dropped some JDAMs then went beck to refuel and rearm but with 2000lbs laser guided bombs. My vertical aiming line was way off to the right of the the target so they were useless. No cue coming down. I did a normal INS alignment so that has nothing to do withit.

Alsoartificial horizon completely off after a dodgy landing and can't seem to reset it. 

It's hard to tell if it's a bug or pilot error from just your description. Has the SPI been moved, are there strong winds, what's the aircraft position relative to the target, etc. ? If you could post a track file or something similar that'd help in figuring out what went wrong.

 

The artificial horizon can tumble some times. It's solved by pushing/pulling the rotary to reset it and scroll to readjust the indicator.

Edited June 19, 2021 by WHOGX5

[=Panther=]

Not a lot of info, so a stab in the dark. Did you shut down when you landed, or did you keep the jet running?

 

If you shut down, did you run another alignment? The alignment isn't saved if you shut down.

[TheTrooper]

5 hours ago, =Panther= said:

Not a lot of info, so a stab in the dark. Did you shut down when you landed, or did you keep the jet running?

 

If you shut down, did you run another alignment? The alignment isn't saved if you shut down.

Yes I did a full shut down. I done a full alignments (normal) afterwards which takes a while. There's no wind I'll do a track file and put it a video on youtube to share.

[Florence201]

Did you complete the rearm before starting engines? Did anyone overfly you or strong surface wind? 
 

these would all affect the alignment 

[TheTrooper]

1 hour ago, Florence201 said:

Did you complete the rearm before starting engines? Did anyone overfly you or strong surface wind? 
 

these would all affect the alignment 

No wind. I done a full INS (norm) so after rearm I was sat around for a while. This is what the hud looks like. Can't drop anything like that in CCRP.
 This was my procedure:
1. Take off with 4x 500lbs JDAMs
2. Take out targets
3. Land
4. Shut down engines
5. Rearm with 2x 2000lbs GBU-10 (my next drop)
6 startup with INS to norm. 

Edited June 20, 2021 by TheTrooper
more specific

[Frederf]

You possibly did the alignment wrong. Within 2min of beginning the norm alignment you have to retype in the lat and long or the INS is flagged as degraded. I made a mistake with the alignment yesterday and a big hint was that the DED was showing something like a 120 knot crosswind near the ground.

 

Here's a track of a bomb, shutdown, start, and bomb.

F-16 restart.trk

[TheTrooper]

3 hours ago, Frederf said:

You possibly did the alignment wrong. Within 2min of beginning the norm alignment you have to retype in the lat and long or the INS is flagged as degraded. I made a mistake with the alignment yesterday and a big hint was that the DED was showing something like a 120 knot crosswind near the ground.

 

Here's a track of a bomb, shutdown, start, and bomb.

F-16 restart.trk 1.98 MB · 1 download

I'll check it it out.
Don't know if this applies but still have the same issue when I start of with JDAMs, bomb targets, land, rearm with LGBs (no shutting down).

[Frederf]

I just picked MK84s the first and second time. The particular bomb type shouldn't make any difference to the issue but anything is possible. Shortest possible track showing the issue would be helpful to look at.

[Florence201]

Most INS related issues are down to an incorrect alignment i my experience. Very easy to screw it up if the procedures aren’t carried out correctly 

[Machalot]

Also pay attention to the lat and lon of your alignment when you restart. I don't know if it always retains the position from your shut down, or if it reverts to the position from mission start. 

 

And of course, don't rearm during alignment. Complete alignment, switch to NAV, then rearm.

[Frederf]

It should retain last position on shutdown. That would be a good thing to test.

 

You can do all sorts of stuff during the latter half of the alignment. Famously you can taxi during normal alignment (in fact moving mid alignment is how you get the best possible alignment). I think at status 60 you're free to move the airplane. The alignment will pause while moving and then resume when still. But movement at the wrong time early in the align is bad.

[Machalot]

1 hour ago, Frederf said:

It should retain last position on shutdown. That would be a good thing to test.

 

You can do all sorts of stuff during the latter half of the alignment. Famously you can taxi during normal alignment (in fact moving mid alignment is how you get the best possible alignment). I think at status 60 you're free to move the airplane. The alignment will pause while moving and then resume when still. But movement at the wrong time early in the align is bad.

If movement causes better alignment during normal align then the Viper works slightly different from the systems I'm familiar with. 

 

Someone should also test whether STD HDG retains or reverts the position.  I think I remember it reverting, which would be a bug, but I'm not sure.

[BIGNEWY]

All seems ok here, as mentioned by others check alignment is correct.

 

thanks