Does the UPS system enable seamless power transfer so that the radar can be powered on while on external power during flight?

• A. True
• B. False
• C. Only for radar
• D. Not specified

Answer: (B)

The UPS is meant to keep critical equipment running with no interruption when the primary power source fails, by providing a seamless transfer to backup power. It is not designed to enable a load to stay powered or to start operating specifically while the aircraft is on external power. In flight, when external power (or the main aircraft power) is available and within spec, the power path typically supplies the radar directly and the UPS is not required to energize or bridge that operation. The UPS steps in only during a loss or degradation of the primary power, not to allow powering on a system under external power. So the statement is not correct.