Abstract: An inverted flight valve between a scavenge pump intake and bottom and top drains of an oil sump in an engine of an aircraft having inverted flight capability, the valve including a valve body with a closed bore therein, a main port in the bore connected to the scavenge pump intake, first and second ports in the bore on opposite sides of the main port and connected to the bottom and top drains, a pair of valve seats in the bore between the main port and respective ones of the first and second ports, and a valve spool having lands at opposite ends slidable in the bore. The valve spool slides in the bore under the influence of gravity between a first position in non-inverted flight wherein one land seats on one of the valve seats to seal the top drain and a second position in inverted flight wherein the other land seats on the other valve seat to seal the bottom drain.