Which engine does the Viking aircraft lack?

The Viking aircraft is classified as a glider, which means it is designed to fly without an engine. Gliders rely on aerodynamic lift generated from their wings to stay airborne, primarily using updrafts and thermals to gain altitude without engine power. This characteristic distinguishes gliders from powered aircraft, which have various types of engines, such as piston engines, turboprops, and turbofans, that provide thrust for flight.

Understanding this unique feature of gliders is crucial for distinguishing them from other aircraft types, as their operational principles and flight tactics differ significantly due to the lack of engine propulsion. Thus, this choice accurately reflects the Viking's design and its capabilities within the context of aviation.