Why the P-61 Raised a Metal Plate to Drop Its Wing

To make the P-61 Black Widow roll, Northrop raised a curved metal surface out of the top of its wing. That surface disrupted the airflow and reduced lift on one side, helping the wing drop. Why would a night fighter deliberately spoil its own lift? The answer begins with the P-61’s large landing flaps. They occupied much of the trailing edge where a fighter would normally use larger ailerons. Northrop combined wing spoilers with small ailerons near the tips to give this heavy, radar-equipped aircraft the roll control it needed. 🔍 Inside this documentary: • Why a purpose-built night fighter needed such large wings and flaps • How a raised spoiler helped the P-61 roll • Why the aircraft still retained small ailerons • What NACA tests revealed about control response and vibration • Why solving one spoiler problem could create another Sources: Smithsonian National Air and Space Museum; NACA research on the P-61’s lateral-control system. Subscribe for more stories about the engineering behind World War II aircraft. #P61BlackWidow #P61 #NightFighter #WW2Aircraft #AircraftEngineering #MilitaryEngineering #AviationHistory #NACA #WorldWarII