What type of fuel system feature allows for inverted flight?

The ability to perform inverted flight relies heavily on the fuel pickup system in the aircraft's fuel system. An inverted flight fuel pickup specifically refers to a design that allows the fuel to be accessed even when the aircraft is in an inverted position. This is crucial because traditional fuel systems may only pick up fuel from the bottom of a tank when the aircraft is in a normal, upright position.

Inverted flight fuel pickups often consist of specially designed tanks or fuel lines that make it possible for the fuel to continue flowing to the engine regardless of the aircraft's orientation. This feature is critical for aerobatic aircraft and those designed for maneuvers that include sustained inverted flight, ensuring that the engine continues to receive fuel without interruption and maintains power during such maneuvers.

Collector tank designs, fuel balancing systems, and pressure relief valves may serve various functions within a fuel system but do not specifically address the issue of maintaining fuel flow during inverted flight. Therefore, the inverted flight fuel pickup is the key feature that allows for safe and effective flight maneuvers in inverted conditions.