OK.134
¶Later on the morning of the 28th, the following discussion oc- curred:
¶D. FR[Firing Room] 2, this is FR[Firing Room] 1.
¶UKN. Yeah Chris.
¶D. This is Dan. We need to send a waiver over for signatures. We're right now showing nose cone gas temps that we were discussing yesterday are down in the 12- 16 degree range and the waiver that we wrote yesterday for 51L only gives us allow- ance down to 28 degrees F. UKN. Yeah, we'll have to rewrite that waiver.
¶D. OK. You don't think we'll have any trouble getting that signed?
¶UKN. No, as long as our pressure transducers are OK.
¶13p bid., 5.1-4.
¶13301S Ciannel245, pp. 220-21.
¶'3'01s Channel 161, p. 289. Channel 161 is identified as an Engineering channel used for troubleshooting and systems integration.
248¶D. OK. What number would you like to use on that Horace? 135
¶Shortly after this conversation concludes, the discussion on pre- paring the ET nose cone temperature waiver continued. Told "[Wle're right now sitting at 10 [degrees]" KSC's Director of Engi- neering said:
¶DIRECTOR. Let's hold on a minute and then we'll write the waiver, we'll probably wanna go below 10.
¶UKN. Yeah, we may just want to say no low and put a note on there that based on the pressure transducers.
¶Director. OK. so vou want us to stand by and wait on that?
¶I <
¶UNK. Yeah.
¶DIRECTOR. OK. We'll be waiting. 36
¶If engineers intended to apply the same rationale for waivers as that used on Janury 27, the rationale is invalid. Ambient tempera- tures were well below the 40 degree limit necessary for a valid backup procedure. Therefore, the backup procedure should not have been employed.
¶Later, in a discussion between the Launch Director and the Di- rector of Engineering regarding countdown problems, the following discussion about the temperature waiver took place.
¶LD. OK. I understand we're in the process of writing a new waiver with a lower limit of lo?
¶DIRECTOR. We're still looking. We'll give you a low limit.
¶LD. What are they running today?
¶DIRECTOR. It's been down as low as 10 basically.
¶LD. Wow! 13'
¶It was in a subsequent discussion between the same principals that the new limit was established. Their conversation, however, does not reflect that the limit was chosen by rigorous technical analysis.
¶LD. We have nothing else, Horace, not unless you guys are working something.
¶DIRECTOR. No, just the ice.
¶LD. OK. The only outstanding item we have right now is the one waiver on the cone temps.
¶DIRECTOR. OK. It looks like we probably could say about 10" and be OK on that one.
¶LD. OK. We'll use 10" then.
¶DIRECTOR. OK.38 Rogers Commission Report, Volume 11, p. F-2. Cmte Hgs, Transcript, July 15, 1986, pp. 10-12, 61. Discussion with NASA personnel, Washington, D.C., May 30, 1986.
¶Completing preparations of the waiver, the Director had the fol- lowing conversation with one of the technicians.
¶DIRECTOR. OK, Jackie, in writing this waiver for nose cone temps we want to put the words on here saying that we can use the ullage transducer as an alternative way of determine redline, but we believe that yesterday Warren Wiley was saying that they had looked at those and they're good down to approximately 11 degrees and we wanted to verify that.
¶J. I think they did to 10 degrees.
¶DIRECTOR. lo?
¶J. Yeah.
¶DIRECTOR. The ullage transducers.