List of most successful aircraft

These are aircraft which were most successful compared to their peers as noted by reliable notable sources

Consolidated B-24 Liberator: Produced in greater numbers than any other American combat aircraft during World War II
Lockheed C-130 Hercules: The Hercules family has the longest continuous production run of any military aircraft in history
Lockheed U-2: In front line service 50 years after first flight. It has outlasted its Mach 3 SR-71 replacement which was retired in 1998.
Douglas DC-3/C-47: Generally regarded as one of the most significant transport aircraft ever made
Boeing 737: The most ordered and produced commercial airliner of all time.
Boeing B-52: The C-130 is the only other military aircraft still in service with original customer after 50 years.
Boeing KC-135: Expected to remain in service into the 2040s, it is likely to outlast even the B-52.
English Electric Canberra: The type remained in service with the Royal Air Force until June 23, 2006, 57 years after its first flight.
Mikoyan-Gurevich MiG-21: One of, if not the most widely produced modern Mach 2 supersonic jet aircraft in the world, with over 8,000 built.
Supermarine Spitfire: Best known British WWII fighter. It was the only fighter aircraft to be in continual production before, during and after the Second World War.