Transitioning from external power to APU power may cause which system to fail?

The correct answer indicates that transitioning from external power to APU power can lead to the failure of the V/UHF 2 radio system. During this transition, there is often a momentary interruption or fluctuation in power supply. This can influence the performance of sensitive electronic systems on the aircraft, particularly in communication and navigation equipment.

The V/UHF 2 radio may be more susceptible to these power fluctuations compared to others, which could result in a temporary loss of functionality or a disruption in its operations. Ensuring stable power during critical transitions is essential in maintaining the reliability of avionics systems, especially for communication devices where uninterrupted operation is necessary for effective coordination and response in aviation environments.

Other systems such as V/UHF 1 radio, UHF 3 communications, and VHF 2 navigation may experience different levels of immunity to power changes or may be designed with safeguards that prevent failure during these transitions. Understanding these electrical transitions and the characteristics of each system is crucial for effective maintenance and operational readiness.