15 April 1969

As part of Operation Beggar Shadow, the United States has been flying signal intelligence flights using spy planes in international waters in order to intercept communications between Eastern Bloc nations while staying outside of their airspace. As part of this, an EC-121M Warning Star, call sign Deep Sea 129, from the US Navy's Fleet Airborne Reconnaissance Squadron One (VQ-1), was tasked to fly a 120 nautical mile racetrack circuit off the east coast of North Korea. VQ-1 has been routinely flying this route for nearly two years, with the assignment graded as 'low risk.' Nearly 200 missions of this type have already taken place off North Korea's east coast this year. Notably, the Beggar Shadow flights were prohibited from flying within 50 nautical miles of North Korea's coast.

The EC-121M Warning Star, an adaptation of the Lockheed L-1049 Super Constellation, arrived on station over the Sea of Japan at 10:35, local time. Shortly after, at 12:34 local time, US and South Korean radar detected the launch of two North Korean MiGs. The track of the MiGs was briefly lost and only re-acquired at 13:37, when they were closing with Deep Sea 129 for a possible intercept. The two MiGs were closing with the American plane at supersonic speed. VQ-1 sent the EC-121M a Condition 3 alert by radio, indicating that they may be under assault. The crew acknowledged the alert and decided to abort the mission, but by then it was too late.

At 13:47 the tracks of the MiGs and Deep Sea 129 converged. The unarmed EC-121 was felled by a single AA-2 "Atoll" air-to-air missile, before the two MiGs returned to North Korea. All thirty-one crewmen onboard were killed, the largest single loss of US aircrew in the Cold War. The North Korean military remained on high alert immediately afterwards, before broadcasting its version of events two hours after the shootdown. Claiming the aircraft had intruded deep into North Korean airspace, it lauded the performance of the pilots for "shooting it down with a single shot by showering the fire of revenge upon it."

The US and its allies were initially unaware the flight had been shot down, but when this became apparent a high priority message was sent directly to President Lyndon B. Johnson. The attack was regarded as a complete surpirse by the United States military.

This incident comes little more than a year after the Blue House raid, demonstrating the aggressive foreign policy of North Korea and the increasing boldness of its actions against the United States and South Korea.