Every year, millions of pilgrims travel to Mecca and other religious sites in Saudi Arabia – and this changes the predominant traffic flow over the African continent. ATC in the most affected FIRs put standard routings in place to help flow that traffic.
Normally, traffic is very north-south predominant, with Europe-Africa flights being the main flow. When Hajj operations start up, a good amount of traffic starts operating east-west (i.e. Africa-Saudi Arabia and vice versa), and this is something to be aware of when cruising along at FL330 with spotty HF comms.
In addition to the normal (IATA Inflight Broadcast Procedure (IFBP)) on 126.9, keep an eye out for a much higher amount of crossing traffic during the coming months.
The affected FIRs are: Algiers, Accra, Brazzaville, Dakar, Jeddah, Kano, Khartoum, N’Djamena, Niamey, Roberts, and Tripoli.