To complement the light observation aircraft, airmen turned to modified fighters for the needed observation over enemy lines. Once the lessons of battle came in, they also modified these planes with bomb racks and operated them in close air support missions. Portrayed are two of the fighter aircraft types of World War II that were modified into fighter-bombers, the Lockheed P-38 "Lightning" (top) and the Bell P-39 "Airacobra" (bottom).