On October 9, 1969, a UH1H helicopter crew and passengers were attempting an extraction from a mined pickup zone in eastern Long Khanh Province, South Vietnam near the shores of the Song Dong Hai River.

During the extraction attempt, the helicopter's rotor blade struck trees, causing the loss of rotor RPM's and lift capability. The Helicopter began losing altitude, turned right and headed west and downriver in an attempt to regain air speed. Shortly thereafter, the aircraft struck 15-20 feet of water and sank on its left side in less than 10 seconds.

Immediate and continuous air and water searches, loudspeaker broadcasts, and phamplet distributions were conducted during the period of 9-15 October and 19-21 October, suspended the 16th-18th only because of poor weather conditions. No recovery was made of any of those missing from the aircraft, but the remains of two personnel aboard were located and subsequently identified.

A LRRP swimmer trying to inspect the site had difficulty staying afloat even with a rope. The individual reported that equipment seen on the shore after the crash appeared to be alternately submerged and then reappear. It could not be determined at the time how many persons escaped the aircraft. One (unnamed in Army records) reported that Dallas could not make it to shore and went under. Another survivor reported seeing Dallas go down within 3-4 feet of him, but never saw him again.

The waters of the Song Dong Nai River were swift and treacherous. It is particularly tragic that men who survived an aircraft would drown trying to reach safety.