Where is the fuel typically carried in most fixed wing airplanes?

Fuel is typically carried in wet wings in most fixed wing airplanes. Wet wings are a design feature where the fuel cells are integrated into the wing structure itself. This approach effectively utilizes the available space within the wings, allowing for greater fuel capacity without adding extra weight or drag that could occur with external tanks.

The design enhances the aircraft's aerodynamic efficiency and keeps the center of gravity within acceptable limits, contributing to better handling and performance during flight. Additionally, the structural integrity of the wings is not compromised; instead, they're designed to support both the aerodynamic forces and the fuel load.

In contrast, while other options like underfloor tanks, wingtip tanks, and fuselage tanks can be employed in specific aircraft designs, they are not the typical means of fuel storage in most fixed wing airplanes. Using wet wings is particularly prevalent in commercial and smaller general aviation aircraft, as it simplifies fuel management and optimizes the overall structure of the airplane.