Final answer:
The Battery Bus and DC XFER Bus OFF lights are not checked on the WAP because they are not critical for flight operations. Pilots have other means to monitor and address these systems.
Step-by-step explanation:
The Battery Bus and DC XFER Bus OFF lights are not checked on the WAP (Warning Annunciator Panel) because these lights are not critical for flight operations. The WAP is a panel on an aircraft's instrument panel that alerts the pilot to any abnormal conditions or malfunctions. It includes lights for critical systems that require immediate attention, such as engine failure, fire, or hydraulic system failure.
The Battery Bus and DC XFER Bus OFF lights indicate the status of the electrical power distribution system, but their absence on the WAP does not prevent the pilot from monitoring or addressing these systems. Pilots have other means, such as the electrical system schematic or other warning systems, to check the status of these buses. Therefore, the Battery Bus and DC XFER Bus OFF lights are not included on the WAP to avoid cluttering the panel and to prioritize the display of critical warnings that directly impact the safety of the aircraft.