Although China introduced their Y-12 light transport in 1986 the aircraft it was meant to replace, the ancient Y-5, is still flying. The Y-12 is a modern design, a 5.3 ton twin engine transport that can carry 17 passengers at up to 328 kilometers an hour. At cruising speed (250 kilometers an hour) the Y-12 can stay in the air for about five hours. One job of the Y-12 is to transport Chinese paratroopers for training, or even combat, jumps.
But it seems the Y-12 has not completely replaced the 1947 era Y-5 biplane transport as far as the paratroopers are concerned. The main reason is that the Y-5 had some useful characteristics that the Y-12 could not match. China began building the Y-5 in 1958 and produced about a thousand of them by 1986. The Y-5 is the Chinese version of the Russian An-2, which is still used worldwide, mostly for civilian chores (crop dusting, fire-fighting and as a light transport). But North Korea still has over 200 An-2s for airborne operations.
The An-2 is a strange bird. It’s a single engine, 5.5 ton bi-plane made mostly of wood and canvas. This makes it difficult to pick up on radar, especially if it’s coming in low, carrying a dozen passengers, at speeds as slow as 60 kilometers an hour. That slow speed makes it excellent for crop dusting, or parachuting commandos to a precise location. In other words the Y-5 is a much more capable “commando” transport than the Y-12. The An-2 range of 800 kilometers is sufficient for North Korea to reach most of South Korea. The An-2 can land on a road or an open field, which is why the North Koreans still have them and probably why China keeps some in service as well.
By 2007 North Korea had ceased, or greatly reduced, training flights of the 300 An-2 aircraft it maintained for delivering commandos into South Korea. The reason was apparently lack of fuel, and spare parts to keep the fleet of aircraft in working order. But a decade later some of those An-2s were again being flown, to help the pilots hone their skills for low-altitude night flights into South Korea, or perhaps China (smuggling)
North Korea obtained some 300 An-2s from Russia in the 1970s and 80s. Some of those were second-hand but the An-2 was easy to maintain if you had the money. The An-2 began production in 1947 and by the time that stopped in 2001 over 18,000 had been built by Russia, Poland and China. Ten percent or more of those are still in service, most of them for civilian chores (including smuggling) in obscure parts of the world.