When you turn on the AUX BAT Switch to ON, which instruments should you check?

• A. Standby Instruments and Backup UHF Control Head
• B. CWS and AEDD
• C. Fire Warning System Test Switch and Engine Instruments
• D. All of the above

Answer: (A)

When the AUX BAT Switch is turned ON, it is crucial to check the standby instruments and the backup UHF control head as these components are designed to provide essential information and communication capabilities if the primary systems fail. The standby instruments are vital for instrument flight maneuvering as they allow the pilot to maintain situational awareness and safety when the main instruments are inoperative.

The backup UHF control head becomes critical during radio communication, ensuring that the pilot can maintain contact with air traffic control and other necessary entities. Therefore, confirming their functionality after activating the AUX BAT Switch is necessary for operational readiness.

While other options list important systems to check, the specific focus on standby instruments and the backup UHF control head directly aligns with the emergency protocols and systems verification after switching on the AUX BAT. It emphasizes maintaining core functionalities essential during critical flight situations, supporting the notion that prioritizing these checks can be vital to flight safety.