Final answer:
APU EGT can fluctuate during the start cycle before normalizing, with exact temperatures dependent on the aircraft and APU model.
Step-by-step explanation:
During the Auxiliary Power Unit (APU) start cycle, the APU Exhaust Gas Temperature (EGT) indication may fluctuate. These fluctuations occur prior to settling into a steady rise to normal operating temperatures. The typical fluctuation range and stabilization temperatures are specific to the aircraft and the APU model, and the exact values can be found in the aircraft's operating manual or pilot operating handbook.
During the APU start cycle, the APU EGT indication may fluctuate between low temperatures prior to normal EGT rise.This is because during the start cycle, the APU's Exhaust Gas Temperature (EGT) is initially low. As fuel is introduced and combustion begins, the temperature gradually increases, eventually reaching the normal EGT range.This fluctuation is normal and indicates the start-up process of the APU. The typical fluctuation range and stabilization temperatures are specific to the aircraft and the APU model, and the exact values can be found in the aircraft's operating manual or pilot operating handbook.