P40 help

[rcflyinghokie]

Auto maneuver puts me in the opposite direction from my sighting attitude. Do I have an alignment issue with the IMU?

Also jump in our discord, we can help a lot faster there in the nassp channel!

 

[ggalfi]

Auto maneuver puts me in the opposite direction from my sighting attitude. Do I have an alignment issue with the IMU?

There are two easy methods to test IMU alignment:
1. Do a P52 with option 3. Use the offered star pair. If the optics, in CMC mode, finds the stars with reasonable accuracy (say, you can see them in the sextant), your alignement is good.
2. Open RTCC MFD. Download the active REFSMMAT (Utility -> REFSMMAT -> DWN). Ask for a P30 Maneuver PAD (Pre-Advisory Data -> Maneuver PAD -> OPT till P30). You may use any fictious DeltaV, for example (+1, 0 ,0), then calculate it. It will give you the GDC backup alignment angles ("Set Stars" in the lower left corner). Orient the CSM to these angles, either by V49, or manually by FDAI#1/Noun 20. Take the CSM G&C checklist and setup optics according to the "Backup GDC alignment" section (this is for Apollo 8: https://www.ibiblio.org/apollo/Documents/A8-CMP checklist-1004.pdf , page 53). If your alignment is correct, you'll see the alignment stars in the SCT on the vertical line, at the proper angle markers.

 

[Phogyaxe]

Okay, so I realigned the IMU using the REFMAT option and I appear to be in sync. But when I run a P23 and go for a sighting I cant get the planet and star in the SXT after activating the slos key (V key). I'm using the flightplan checklistand following that for my P23. What am I doing wrong?

 

[Phogyaxe]

There are two easy methods to test IMU alignment:
1. Do a P52 with option 3. Use the offered star pair. If the optics, in CMC mode, finds the stars with reasonable accuracy (say, you can see them in the sextant), your alignement is good.
2. Open RTCC MFD. Download the active REFSMMAT (Utility -> REFSMMAT -> DWN). Ask for a P30 Maneuver PAD (Pre-Advisory Data -> Maneuver PAD -> OPT till P30). You may use any fictious DeltaV, for example (+1, 0 ,0), then calculate it. It will give you the GDC backup alignment angles ("Set Stars" in the lower left corner). Orient the CSM to these angles, either by V49, or manually by FDAI#1/Noun 20. Take the CSM G&C checklist and setup optics according to the "Backup GDC alignment" section (this is for Apollo 8: https://www.ibiblio.org/apollo/Documents/A8-CMP checklist-1004.pdf , page 53). If your alignment is correct, you'll see the alignment stars in the SCT on the vertical line, at the proper angle markers.

Okay, so I realigned the IMU using the REFMAT option and I appear to be in sync. But when I run a P23 and go for a sighting I cant get the planet and star in the SXT after activating the slos key (V key). I'm using the flightplan checklistand following that for my P23. What am I doing wrong?

 

[rcflyinghokie]

Okay, so I realigned the IMU using the REFMAT option and I appear to be in sync. But when I run a P23 and go for a sighting I cant get the planet and star in the SXT after activating the slos key (V key). I'm using the flightplan checklistand following that for my P23. What am I doing wrong?

As I asked before, can you post a scenario where you are having the issue? There are a number of things you could be doing wrong here.