>How could a drone fly for 6 hrs?
The Shahed-136 Kamikaze drone is launched using a rocket situated below the fuselage, which gets separated by a pod jettison system immediately after launch.
Further, a conventional Mado MD550 four-cylinder, two-stroke piston engine situated at the rear of the fuselage drives a two-blade pusher propeller to move the drone forward.
The drone can achieve a maximum speed of 185km/h and is claimed to have a range of 2,500km.
https://www.army-technology.com/projects/shahed-136-kamikaze-uav-iran/?cf-view