The Boeing F4B is a biplane fighter aircraft that was used by the United States Navy and Marine Corps in the 1930s. It features a distinctive design with two wings stacked one above the other, providing enhanced maneuverability. The F4B was powered by a radial engine and could reach speeds of around 200 miles per hour. Introduced in 1929, the F4B played a crucial role in the transition from biplanes to monoplanes in military aviation. It was known for its agility and performance, making it a favorite among pilots of its time. The aircraft was eventually phased out as more advanced designs emerged.