The Board is a Fig Leaf, nothing more. It can be safely ignored, in fact why anyone would want to serve on a powerless Board is beyond my imagination. CASA, as a Government owned corporation, needs "a Board" to comply with the incorporation rules.
In a normal corporation, the Board firstly protects the corporations assets, is responsible for corporate governance, chooses and appoints senior management and ensures they are working to a coherent corporate strategy for the benefit of the shareholders.
CASA is not a "normal" corporation. It exists to insulate Government from the consequences of its own (in)actions and policy through a process called diffusion of responsibility ("the Board did this, I'm just the Minister"). The reality is that the Government exercises day to day control of what happens at CASA but can blame the Board if anything goes wrong.