The U.S. Navy recently put a rebuilt C-47 twin-engine transport into service as a range support aircraft for its ATR (Atlantic Test Range). The navy needed a larger range support aircraft so that more radar and tracking equipment could be carried and track multiple jets and missiles they had in the air at once. The old ATR was a King Air, twin-engine commercial turboprop transport introduced in the 1969s, three decades after the DC-3, an aircraft that was renamed the C-47 during World War II. A new King Air, or similar but larger aircraft, would not only cost a lot more than the rebuilt (as a BT-67) C-47 but would take longer to obtain.
The C-47 was a legend in the U.S. military and many are still encountered overseas where they still serve as civilian or military transport. The BT-67 got two new engines, a modern glass cockpit and replacements to airframe components that needed it. There are a lot of suppliers for DC-3/C-47 replacement parts, which meant no expensive custom-made components were required. The U.S. Navy began using the DC-3 during the 1930s and by 1941 was a major customer for the military version, which the navy called the R4D. The navy adopted the DC-3 before the U.S. Army Air Force ,and military versions of the DC-3 were on active U.S. service through the 1970s.
The DC-3 was another example of an aircraft design that never gets old, they just get better. The pre-World War II DC-3 has long been a prime example of this. Many are still used in South America. One example of this is Colombia. Starting in the 1990s Colombia paid about $5 million each to convert seven C-47 transports to AC-47T Fantasma (“spooky”) gunships. These carried a seven-man crew and were equipped with night vision sensors and a three-barrel .50 caliber machine-gun or a 20mm autocannon and sometimes a few bombs. Two AC-47Ts were lost to accidents but by 20201 six were still in service patrolling the coasts and remote interior forests searching for drug gangs or leftist rebels. Typical missions last about ten hours, usually at night.
AC-47s gunships first appeared in the 1964 over Vietnam. Back then there were thousands of relatively new C-47s to be had. The troops called these AC-47 gunships, which preferred to operate at night, thus the "Spooky." During the 1960s 53 AC-47s served in Vietnam and 36 percent were lost in action, usually to accidents and mechanical failure. The AC-47 was soon superseded by larger armed transports, especially the 1950s era C-130.
The DC 3 continues to fly in commercial service into the 21st century. Back in the 1990s several hundred DC 3s could be found flying worldwide, mostly owned by small domestic carriers in the U.S. and by some Third World air transport companies. A state-of-the-art aircraft in the mid-1930s, during which only 500 were built, that all changed in 1939. Over 35,000 DC 3's were produced for military use during World War II as C-47s, R4Ds, Dakotas and a number of other names. The DC-3 was, in fact, the most widely manufactured aircraft of the war. As of 2020 over 300 of them are still in service with military and commercial operators, a number largely unchanged since the 1990s.
When allied paratroopers jumped, it was usually from a C-47/DC-3, which could carry 28 troops, but over sixty people were squeezed in during emergencies. With a maximum range of 3,400 kilometers and a top speed of 296 kilometers per hour, the DC 3 was a common cargo carrier (up to 3.5 tons) and general purpose "flying truck." It still is, even though production ceased by 1944. Since then, the rugged and reliable design has been constantly upgraded with better engines and electronics as well as new mechanical and structural components that are stronger and longer-lasting than the originals. Because of that the most modernized DC-3s can carry at least five tons of cargo. All the DC-3/C-47s remaining in service are over 70 years old and some will still be flying a century after the first one entered service.
The refurbishment of DC-3s has been going on for decades. The most successful and thorough upgrades were done by an American firm (Basler Turbo Conversions). This outfit did the conversions for Colombia to produce the AC-47T. The new turboprop engines are more efficient and reliable and its modern cockpit has all flat screen displays with sensors constantly monitoring the condition of the rebuilt aircraft. The BT series of DC-3 transports competes successfully as a more affordable alternative to much more recent designs. Current users of the BT conversions include Colombia, El Salvador, Guatemala, Mali, Mauritania, Thailand, and now again by the United States government. Only the Colombians bought an armed model, all the other users have cargo or surveillance models. The BT aircraft are well suited for this because they have a cruising speed of 375 kilometers an hour and a low service ceiling of 4,000 meters (13,000 feet).