I am just generally unsure how thie issue of the korban at a fixed time fits in with tuma'h hutra and dechuyah betzibur. As far as I can tell, Even according to the m'd tuma'h hutra betzibur, this applies even to a korban tzibur AND fixed time, but a korban yochid AND FIXED time would be dechuya. But I am having a hard time spelling out the klolim. Thanks.
moshe rubin, bklyn, ny
Moshe,
Here is a copy of what we wrote on the subject in our Background to the Daf. If you have more specific questions, please write again and we will try to help.
Best wishes,
Kollel Iyun Hadaf
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12) [line 10] TUM'AS HA'MES HUTRAH HI B'TZIBUR/ DECHUYAH HI B'TZIBUR
(a) The Torah permits offering Korbenos Tzibur (communal sacrifices) b'Tum'ah. Therefore, Korbenos Temidim and the Musafim of Shabbos, Yom Tov and all other Korbanos and Menachos that are brought for the Tzibur, such as Minchas ha'Omer and the Shtei ha'Lechem, may be offered even if there is a need to offer them b'Tum'ah (as will be explained below).
(b) The Tana'im argue whether Tum'ah is Hutrah b'Tzibur or Dechuyah b'Tzibur (Pesachim 77a, Yoma 7b).
1. The Gemara in Yoma explains that according to all opinions, if certain Kohanim in the Mikdash are Teme'im and others are Tehorim, the Tehorim do the Avodah. However, if all of the Kohanim of the Beis Av (the group of Kohanim whose day it is to do the Avodah) are Teme'im, there is a dispute as to whether the Korbanos are offered b'Tum'ah. One opinion holds that the Torah entirely cancelled the prohibitions against Tum'ah with regard to Korbenos Tzibur ("Hutrah"); therefore the Kohanim who are Temei'im may perform the Avodah. Others rule that Kohanim from other Batei Avos who are Tehorim should be sought to do the Avodah, since only with reluctance did the Torah permit offering Korbenos Tzibur b'Tum'ah ("Dechuyah"). The prohibitions of Tum'ah are only pushed aside in the event of great necessity.
2. Another practical difference that arises from the argument whether Tum'ah is Hutrah or Dechuyah is that according to the opinion that Tum'ah is Dechuyah b'Tzibur, a Korban Tzibur in which the blood, flesh or Chelev became Tamei may only be offered in conjunction with the conciliatory effects of the Tzitz (see Background to Pesachim 77:7b). If the Tzitz is not Meratzeh for the Korban, the Korban may not be offered b'Tum'ah (Pesachim 77a).