Thank you for all answers,
That is sure at least 1 QRH should be on board, but it is still not clear the 2nd is required.
Anyway, I should also state the origin of this thread, maybe it helps.
During the SAFA inspection of one of the company (JAR) airplane in a JAR member country, absence of second QRH is recorded as findings. That`s why this discussion is started whether the 2nd QRH is really required.
Thank you