The air fleet moved swiftly above the clouds. Only Ronisca in the Otherworld had aerial vehicles, so there were no specified air routes, nor was there any concern about aircraft colliding.
During the air fleet's flight, two ground-support ships continually released high-speed reconnaissance aircraft to conduct ultra-low-altitude flights. These aircraft confirmed the current coordinates of the air fleet and searched for the so-called virus and engine.
These reconnaissance aircraft were no longer the propeller-driven type of the past. They were equipped with a type of turbofan engine. Compared to propellers, the primary advantages of these engines were their lower noise and significantly improved speed.
They were termed 'like turbofan engines' because their operating principle was completely different from the turbofan engines of Earth.
