What could be a consequence of failing to vent aircraft fuel tanks?

Failing to vent aircraft fuel tanks can lead to pressure buildup within the tanks. As fuel is consumed during flight, it creates a vacuum that prevents more fuel from flowing in to replace what has been used. Without the ability to equalize pressure through proper venting, this build-up can reach a point where it compromises the structural integrity of the tank, potentially causing it to rupture. Ruptured fuel tanks can lead to severe safety hazards, including fuel leakage and the risk of fire.

This issue is particularly critical as aircraft are designed to operate under specific pressure conditions. The venting system plays an essential role in maintaining those conditions, ensuring both safe operation and optimal fuel flow. The other options relate to important factors in aircraft fueling but do not directly stem from the lack of venting in the same way; they may be secondary consequences rather than primary risks associated with pressure buildup.