Charlie Duke

Okay. Turning to the next page and the last page, Jim, 34. Top of the page, “Monitor DELTA-VX via 470.” Scratch next two lines, “When propellant quantity equals 37” and the “DESCENT HELIUM REG.” Scratch “TTCA commander, reduce to 10 percent.” Now we want you to add a line; “shut”—It's a shutdown criteria, “shutdown on burn time minus 1 second.” Over.

Jim Lovell (CDR)

Okay, “The shutdown is on burn time minus 1 second.” Let me give you an example. If we have a 30-second burn, we're going to shut down at 29 seconds. Is that correct?

Charlie Duke

That's affirmative. We'll give you the pad, be coming up here from FIDO in a couple of hours, I guess, when we stabilize out on our tracking. The reason for—If you're ready to copy out a couple of more steps, and then I'll explain the reason we want to shut down on this burn time minus 1 second. Picking up on "When DELTA-VX

Charlie Duke

“— When DELTA-VX equal to the final DELTA-VX,” scratch that line. Scratch “ATTITUDE CONTROL: YAW, to PULSE.” Add—Correction, scratch “Damp excessive rates via LM Y, Z translation” and add at that point “Null” error needles. Trim address 470 to 0.1 foot per second." Over.

Jim Lovell (CDR)

Okay, going through. After the “Shutdown on burn time minus 1 second,” we scratch the next line; and we scratch “ATTITUDE CONTROL: YAW, to PULSE”; we scratch “Damp excessive rates via LM Y, Z translation”; we add the line “Null” error needles, trim—Null the error needles and trim address 470 to—What was the value there, Charlie?

Charlie Duke

“0.1 foot per second.” The reason we are shutting down on the burn time is, since the ASA breaker has been out for so long, we're not real confident that our AGS PIPAs are going to be super-sharp. So we want to make sure that we just get a burn time—no overburn; so we're shutting down on burn time minus 1 second. And then that will allow us a plus-X translation to trim 470 if it looks okay. If we had an overburn, we'd be in —

Charlie Duke

— if we had an overburn, we'd be impinging on our command module to try to trim it out, so that's our reasoning there. Over.

Charlie Duke

Okay. Picking up in the middle of the page, that—a block “CMS resume attitude control,” scratch. Scratch the next line; “PRO VERB 96.” Scratch the third line; “PROPELLANT QUANTITY MONITOR, OFF.” Over.

Jim Lovell (CDR)

Okay. We'll scratch the blocks, and we'll scratch the “PRO VERB 96”; then we'll scratch “PROPELLANT QUANTITY MONITOR, OFF.”

Charlie Duke

Roger. Now, at the bottom of that page, I have a procedure for you to reestablish PTC. Over.

Jim Lovell (CDR)

To reestablish PTC. Go ahead.

Charlie Duke

Okay. First line, “ATTITUDE CONTROL, three to PULSE”; line 2, “Roll with the TTCA until attitude is roll, plus or minus 90; pitch, 0; yaw, 0.” Over.

Jim Lovell (CDR)

Okay. Step 1, “ATTITUDE CONTROL, three to PULSE”; 2, “Roll with the TTCA … pitch is 0 and yaw is 0,” and I think that will be on the AGS ball.

Charlie Duke

That's affirmative. You broke up there for a minute, Jim. We'll do that on the AGS ball from the burn attitude. We just want you to roll either way 90 degrees, keep pitch 0 and yaw 0. Now, step 3; “When at—when at attitude, ACA out of detent.” Step 4; “ATTITUDE CONTROL: YAW, to MODE CONTROL. When rates are less than 0.05, ATTITUDE CONTROL: YAW, to PULSE.”

Jim Lovell (CDR)

Okay, Charlie. Can you hold up here a second? I lost you.

Jim Lovell (CDR)

Start with step 3 again. “When attitude—When at attitude, ACA out of detent.”

Charlie Duke

That's Roger. Next step, step 4: “ATTITUDE CONTROL to YAW”—Correction, “ATTITUDE CONTROL: YAW, to MODE CONTROL.” Over.

Jim Lovell (CDR)

Okay. Step 4 is “ATTITUDE CONTROL: YAW, to MODE CONTROL.”

Charlie Duke

Roger. Step 5: “When rates are less than 0.05 degrees per second, ATTITUDE CONTROL: YAW, to PULSE.”

Jim Lovell (CDR)

Okay. “When rates are less than 0.05 degrees per second, ATTITUDE CONTROL: YAW, to PULSE.”

Charlie Duke

Roger. Step 6: “Spin up to 0.3 degree per second in yaw,” and that takes about 21 pulses. Step 7—Yes.

Charlie Duke

Okay. Step 7: “MODE CONTROL, AGS, OFF.”

Jim Lovell (CDR)

Okay. Step 6 was “Spin up to 0.3 degrees per second in yaw”; that's about 21 pulses. Step 7 was “MODE CONTROL, AGS, to OFF.”

Charlie Duke

That's affirm. Step 8: “Power down per power”—Correction, “Power down per contingency checklist page Power 5.” Over.

Jim Lovell (CDR)

Okay. And step 8 is Power down per contingency checklist Power 5," and I take it that's been revamped considering our situation. Okay.

Charlie Duke

That's affirmative, Jim. That's the one we gave you last night after the big burn, and we'll use that one as modified by—by us. This—we tried this PTC under AGS in the simulator and, of course, no slosh or anything, but it seemed to work pretty good by nulling the rates using the TTCA in pitch and roll and letting the ACS do it in yaw. You null the rates by looking at the error needles and just watching those, and when they don't—when they stop moving, then you got it within the limits of what we want. Over.

Jim Lovell (CDR)

Okay. And I guess, Charlie, you have no—Do you have a ATT hold mode in pitch and roll at all in this configuration we're in, or do we have to use the TTCA?

Charlie Duke

We feel like we have to use the TTCA. The AGS gains are not too good in pitch and roll in this configuration. It'll hold it in yaw but it won't in pitch and roll. Over.

Charlie Duke

And you'll have—During the burn, of course, you'll be controlling pitch and roll via the error needles with the TTCA also, and it's the little scheme that we've practiced in some of the SIMs. Over.

Jim Lovell (CDR)

And, Houston, want to make sure that we allow enough time to get to the proper attitude for the burn so that we can be sure we establish the proper attitude and don't have to rush the burn.

Charlie Duke

Roger, Jim. We -we're looking right now, tentatively, at starting this about 45 minutes before the burn and our sensitivity is—not too bad on this burn. We can go 30 minutes either way and not affect our DELTA-V. Over.

Jim Lovell (CDR)

Okay. Fine. And do you have a handle on just how long the burn will be? In time?

Charlie Duke

It's looking like at about 7.8 seconds and about 15—Correction, 7.8 feet per second and about 15 seconds. Over.

Charlie Duke

Negative. 15. 1 5.

Charlie Duke

And one other point is that we'd like to remind you that this is going to be in blowdown and both REGs B closed but we've got plenty at the 10 percent.

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Spoken on April 16, 1970, midnight UTC (53 years, 11 months ago). Link to this transcript range is: Tweet

Charlie Duke

And, Jim, in the simulator with our configuration that we had here, the thing is real stable at 10 percent, so we don't think you'll have to tweak very much at all using the TTCAs. Over.

Charlie Duke

And I'll give you back to Vance. Thank you.