* North Korean drones have been flying over South Korea for a minimum six months, yet the South Korean military and intelligence authorities had no clue.
* Drones flew between the Yellow Sea and the East Sea over the nuclear power plants in Uljin and over areas dense with military units.

Another drone speculated to be from North Korea was discovered on April 6, supporting claims that North Korea may have long used the drones for military reconnaissance missions over a vast area. The lack of awareness by the military and intelligence authorities is being exposed one by one, and criticism is expected to intensify for the holes in our air defense network.

* A hole in the east coast

The drone in Samcheok, Gangwon Province was first discovered on October 4, 2013. Given that a drone was discovered similar to the ones found in Paju-si, Gyeonggi Province and Baekryeongdo in the Yellow Sea last month, it appears the North Korean military has steadily used the unmanned aircrafts for at least over six months. A look at the areas where the drones were found shows that the drones liberally flew over all areas surrounding the military demarcation line, where military units are densely located, from the Yellow Sea to the East Sea. The Uljin nuclear power plants are located in the east and the coastal areas are heavily concentrated with military units.

The drones discovered in South Korea were manufactured using a molding method, which allows for mass production. Tens or hundreds of drones could have been mass produced and used. There was a serial number written on the drone which crashed in Paju, and it was confirmed that the parachute used in landing had been folded and unfolded eight times. Some say that it is likely that the drone discovered in Baekryeongdo on March 31 may not be the drone which crashed after our military fired a Vulcan cannon at a flying object detected on radar, but a third drone. The military also said, "We will conduct reconnaissance patrol at all units from April 7 keeping in mind the possibility that additional drones may have penetrated our skies."

It was not the military, which had first discovered the three drones. Given their words, "There are no suspicious targets for anti-aircraft activities," when a drone was discovered in Paju, it appears the military and the intelligence authorities had absolutely no information on the latest type of drones. The areas penetrated by the drones were high in risk, including Cheong Wa Dae, Baekryeongdo near the Northern Limit Line (NLL) in the Yellow Sea, and Samcheok, near the Uljin nuclear power plants. In particular, military helicopters and reconnaissance aircraft frequently fly over the Gangwon region, leaving room for more criticism on the military's poor air defense network.

* The performance and type of the North Korean drones
The defense ministry is aware of 4-5 types of North Korean drones. A typical drone is the Panghyon-I, II, a Chinese drone (D-4) which the North renovated into a reconnaissance aircraft. It is 3.6 meters long, with a wingspan of 4.8 meters and can fly at a maximum speed of 162 km/h. The North Korean military also has VR-3 Reys, which they imported from the Middle East in the late 1990s, and Pchela-1Ts from Russia. They are currently developing a drone named, Durumi (crane), which is capable of attack and reconnaissance at the same time.

North Korea also announced that they developed unmanned attack drones which fly and crash into the target in March 2013. According to an assessment by the South Korean military, this drone has an attack range of 600-800 km, which includes the entire South Korean territory.
The military explained that they could thoroughly detect and attack the drones they have already identified. But the newly discovered drones are difficult to detect with conventional radar, for although the technology is rudimentary, they are small in size and made of plastic.

The Joint Chiefs of Staff announced, "First we will seek defensive measures with our current military power, and reinforce our response forces as soon as possible."