What is the purpose of the PDU/MDU button on the Reversion Panel?

The PDU/MDU button on the Reversion Panel is essential for managing the display modes of the instrumentation within the cockpit. When selected, this button allows pilots to toggle between Primary Display Unit (PDU) and Multi-Function Display Unit (MDU) modes, ensuring the necessary flight information can be accessed in various scenarios.

Switching display modes is crucial during flight when different information may be needed depending on the aircraft's operational conditions or pilot preferences. This flexibility allows pilots to maintain situational awareness and respond to changes efficiently.

The other functions mentioned, such as displaying engine parameters, managing fuel levels, or indicating cabin pressure, are important in their own right, but they do not pertain to the specific function of the PDU/MDU button. Instead, those operations are managed through other dedicated systems and indicators within the aircraft's avionics suite.