Speedbird
On the 747-300 B zone is usually blocked off for the crew on long sectors.
eg when it was being used on the LAX AKL LAX sectors B zone was always blocked off, this was in the CCN and it was also issued as a CSM briefing sheet so the CSM would not have been in trouble for allowing the crew to rest there.
indamiddle call the FAAA and ask them, this information is freely available to anyone that is a FAAA member, or if your game call the visitors!