WASHINGTON, Dec. 19 -- The Pentagon on Monday imposed a flight restriction on all U.S. military aircraft for the buffer zone along South Korea's border where an Army helicopter was flying before it drifted off course and went down in North Korea. The restriction was one of several actions taken by the Pentagon pending the completion of a full investigation of training and flight procedures being used by the U.S. Army in along the border between North and South Korea, a senior defense official said on Monday. Army Gen. Gary Luck will lead the investigation and brief Defense Secretary William Perry and the Joint Chiefs of Staff on the findings. Other actions taken Monday include requiring pilots to take a refresher training course on flying in the buffer or tactical zone known as P-518, the official said. The 25-mile-wide zone acts as a buffer between South Korea and the outer edge of the no-fly zone, which is 3 to 9 miles from the North Korean border. Actions taken Monday also include the requirement that any future flights over P-518 will need to first be approved by a battalion commander, the defense official said. The Pentagon would not speculate as to why the unarmed OH-58 Kiowa surveillance helicopter drifted more than 10 miles off course and 2 to 3 miles into North Korean airspace Saturday while on a routine training mission. Defense officials also declined Monday to offer an explanation for the cause of the crash.
It remained unclear whether North Korean troops along the demilitarized zone with South Korea shot them down, as North Korea maintains, forced them down or merely captured them after a crash landing. U.S. officials have been told by North Korea that Army Chief Warrant Officer Bobby Hall, the pilot of the aircraft, survived the crash unharmed, while the co-pilot, Chief Warrant Officer David Hilemon, was killed. Hall, an experienced pilot who has logged more than 900 hours of flying time on the OH-58 Kiowa, was being held captive by North Korea. He was taking Hilemon on the first of two routine training missions Hilemon needed to be certified to fly in the region, the official said. The helicopter was said to be traveling at speeds up to 150 miles per hour, at roughly 100 feet off the ground, in training mission skirting near the North Korean demilitarized zone. Such missions are designed to teach pilots where the borders of the DMZ lie. A fence marking the border between the two countries can generally be clearly seen by helicopter pilots flying low to the ground, the official said. On the day of the incident, visibility was said by the Pentagon to be 'about 6 miles or better, with a 10,000-foot ceiling' for clouds, eliminating the possiblity that poor visual conditions contributed to the pilot drifting into North Korean airspace. The official, speaking on condition of anonymity, said Hall followed normal flight procedures for such a mission. 'We don't know all of the facts yet because we have not talked to (Hall),' the official said. He said, however, that at one point, the pilot reported by radio to be at a checkpoint but was actually more than 10 miles north of that location. 'Clearly, they were not where they thought they were,' he said. The Pentagon said it would review the training procedures and standards placed on pilots for flying near the North Korean DMZ, examine warning procedures in place to caution pilots who may drift into hostile airspace, and evaluate helicopter navigation aids.