Africa is a big place
If memory serves, Africa has a surface area roughly equal to that of the moon. There are a lot of places to hide things, especially if you're getting help from the local government. A 727 cruises over 500 MPH, so it can cover a lot of territory in a short time, so it might not even be in Africa anymore.
As for the satellites, they're good but they can't see inside of a hangar unless the doors are open.