Help defining Apollo acronyms & terms

[bimbambaby]

Hello -

I was looking at a transcript of the A-17 LEM descent, and I was wondering if someone out there might be able to help me define them:

CWGA - Does this stand for "Caution & Warning, General Alarm"?

CDR ACA - Commander's attitude control assembly?

Also, if someone could provide me with a breakdown of this passage, I'd sure appreciate it (I know what verb and noun correlate to, however, I was wondering if someone could tell me what the specific codes mean):

"Verb eleven, noun ten, thirty-one, enter. R one is six seven seven seven seven. CDR ACA, out of detent, two and a half degrees. Pause two seconds at null

Okay, fifty seven is good. Roll left, thirty seven is good. Yaw right twice, slowly."

Do fifty seven and thirty seven refer to thruster points?

I realize if this is an unusual request, but I sure do appreciate any help you can offer.

Thanks!

[echnaton]

Welcome to the board, bimbambaby. Your questions are out of my range of knowledge, someone else should be able to help you.

[ajv]

Welcome.

That isn't actually during the LM descent is it? In the transcript I have that occurs at 109:44:11-ish (if I've calculated 2:40:00 offset correctly) during the RCS checkout of the LM activation.

Jack is working through the RCS Checkout procedure. For comparison, the Apollo 15 checklist section is on page 2-24 of LM Activation Checklist.

My understanding of the 57 and 37 numbers is that they show the computer is detecting the current state of the Attitude Controller correctly.

Jack enters:

Verb 11 - Monitor Octal Comp 1 in R1.
Noun 10 - Channel to be specified. Enter.
Channel 31 Enter.

Here's the info on Channel 31 from the Luminary 131 listing:

Channel 31

Input channel; bits associated with the Attitude Controller, Translational Controller, and Spacecraft Attitude Control; Used by RCS DAP.

• Bit 1 - Rotation (by RHC) commanded in positive pitch direction; must be in minimum impulse mode. Also positive elevation change for landing point designator.
  
• Bit 2 - As Bit 1 except negative pitch and elevation.
  
• Bit 3 - Rotation (by RHC) commanded in positive yaw direction; must be in minimum impulse mode.
  
  
• Bit 4 - As Bit 3 except negative yaw.
  
• Bit 5 - Rotation (by RHC) commanded in positive roll direction; must be in minimum impulse mode. Also positive azimuth change for landing point designator.
  
• Bit 6 - As Bit 5 except negative roll and azimuth.
  
  
• Bit 7 - Translation in +x direction commanded by THC
  
• Bit 8 - Translation in -x direction commanded by THC
  
• Bit 9 - Translation in +y direction commanded by THC
  
  
• Bit 10 - Translation in -y direction commanded by THC
  
• Bit 11 - Translation in +z direction commanded by THC
  
• Bit 12 - Translation in -z direction commanded by THC
  
  
• Bit 13 - Attitude hold mode on SCS mode control switch
  
• Bit 14 - Auto stabilization of attitude on SCS mode switch
  
• Bit 15 - Attitude control out of detent (RHC not in neutral)
  

57 and 37 (and later 67 and 73) are last two octal digits of Channel 31.

Octal	654	321
57	101	111
37	011	111
67	110	111
73	111	011

You can see the 0 moving through the control bits for positive roll, negative roll, negative yaw, positive yaw.