It was recently revealed that North Korea again flew its UAVs into South Korea on August 22-24th and this time South Korea had radars in place that could spot and track them. South Korea sent up fighters and attack helicopters to take down the UAVs but it is unclear if they were successful. Unlike the smaller UAVs used in 2014 this time they were larger models, apparently based on the Chinese D-4/ASN-104. North Korea has had this model for some time. North Korea had been interested in UAVs since the 1970s but had never bought or built a lot of them. In the late 1980s North Korea acquired some of China’s first generation UAVs (ASN-104s). These were 140 kg (304 pound) aircraft with a 30 kg (66 pound) payload and endurance of two hours. Very crude by today’s standards but it took real time video and higher resolution still photos. In the 1990s the North Koreans produced some ASN-104s, apparently by just copying the Chinese ones they had. In the 1990s North Korea got some Russian DR-3 jet powered UAVs. These were faster but less useful than the ASN-104s. Attempts to use the DR-3 as the basis for a cruise missile design failed. In the 1990s North Korea also got some Russian Pchela-1T UAVs. These were very similar to the ASN-104s and that means not very useful at all. The Chinese and Russians used these first generation UAVs mainly for correcting artillery fire and this is what North Korea was seen doing with them, particularly North Korean coastal artillery. The ASN-104s are expensive to maintain and it was believed that North Korea was switching to smaller, more capable and cheaper UAVs based on Chinese commercial models. North Korea is believed to have over 300 UAVs, many of them elderly and probably not operational. Some are equipped as crude cruise missiles.
In early 2014 there was some shock and surprise in South Korea when the remains of three North Korean UAVs that had crashed in South Korea were found. A close examination of the wreckage revealed that North Korea was using modified versions of the commercial Chinese SKY-09P UAV. North Korea gave the SKY-09Ps a new paint job (to make it harder to spot), a muffler (to make it less detectable) and installed a different camera. The SKY-09P was used via its robotic mode, where the SKY-09P flew to pre-programmed GPS coordinates, taking digital photos over selected areas and returned with those photos stored on a memory card. The SKY-09Ps found in South Korea had GPS coordinates in their guidance system showing they originated and were to return to a location in North Korea. The memory cards showed pictures of South Korean government (mainly military) facilities.
The Chinese SKY-09P is a 12 kg (26 pound) delta wing aircraft with a wingspan of 1.92 meters (6.25 feet), propeller in the front and a payload of three kg (6.6 pounds). It is launched via a catapult and lands via a parachute. Endurance is 90 minutes and cruising speed is 90 kilometers an hour. When controlled from the ground it can go no farther than 40 kilometers from the controller. But when placed on automatic it can go about 60 kilometers into South Korea and return with photos. These things cost the North Koreans a few thousand dollars each. While South Korea says they detected two of the three crashed North Korea UAVs no other details were provided. The Chinese manufacturer denied selling anything to North Korea, but the North Koreans typically use a third party for purchases like this. North Korea has apparently concluded that robotic (and thus impossible to electronically jam) UAVs flying very low were the best way to scout out South Korea border defenses and facilities.