What is a drawback of pressure fueling systems in light aircraft?

Pressure fueling systems are indeed more complex than gravity fueling systems commonly used in light aircraft. This complexity arises from the additional components and mechanisms required to safely pressurize the fuel and manage its flow. Systems involving pressure require valves, pumps, and associated controls to maintain and regulate the pressure, which adds to both the design intricacies and potential points of failure that must be monitored.

In addition, the complexity can lead to increased training requirements for ground personnel and pilots who must understand the operation and safety protocols associated with these systems. While pressure fueling offers advantages such as faster refueling times and the ability to refuel in varied orientations, the complexity involved is a significant drawback, particularly when evaluating operations for light aircraft, which may prioritize simplicity and ease of maintenance.

The other options mentioned, such as increased weight and maintenance costs, can occur depending on the specific design and implementation of the fueling system, but the defining characteristic of pressure fueling that stands out is its inherent complexity compared to simpler systems.