All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
The issue of reciting Surah Al-Faatihah behind the Imam is one of the issues on which the scholars have greatly differed in opinion about since the era of the Companions, may Allah be pleased with them, and those who came after them up until today.
The opinion that we consider to be the preponderant one, is that it is obligatory to recite Al-Faatihah for a person led in prayer in every Rak'ah of the prayer, whether it is in silent Rak'ahs or the ones recited aloud. This based on the general statement of the Prophet : “The prayer of the one who does not recite the opening Chapter of the Book [i.e. Al-Faatihah] is void.” [Al-Bukhaari and Muslim]
However, many scholars are of the view that reciting Al-Faatihah is not obligatory for the person led in prayer, neither in silent prayers nor in ones recited aloud. Ibn Qudaamah said:
"To conclude, the recitation [i.e. of Al-Faatihah] is neither obligatory for the person led in prayers which the Imam recited aloud, nor in prayers that are recited silently. Imam Ahmad explicitly stated this as conveyed by the majority of his students. This is also the view of Az-Zuhri, Ath-Thawri, Ibn ‘Uyaynah, Maalik, Abu Haneefah, and Is-Haaq. However, Ash-Shaafi'i and Daawood said that it is obligatory.” [End of quote]
Allah knows best.