SP5 Gary C. David 

SP5 Frank A. Sablan

For most of the men with the 371st Radio Research Company based at Phouc Vinh, South Vietnam, March 1, 1971 

was shaping up to be a normal day. Spring had arrived. It was 80 degrees and sunny, and a pleasant breeze 

blew across the base. That morning, four men headed out to board flight 69-15684. WO1s Paul Black and Robert 

Uhl of the 1st Cavalry’s 11th Aviation Company were slated to pilot the UH-1 helicopter flight. The other two crew 

members, SP5s Gary C. David and Frank A. Sablan, were cryptologic professionals whose job was to locate 

enemy units via airborne radio direction finding. 

David was born in on December 20, 1949 in Pottsville, Pennsylvania and raised in the Miami Beach, Florida area. 

He enlisted in the US Army in 1958, and after extensive testing, he was selected to serve in the Army Security 

Agency (ASA), the cryptologic element of the US Army during the Vietnam era. After basic and advanced 

training as a Morse intercept operator, he was sent to Korea for a year before deploying to Vietnam in December 

of 1969. 

Sablan was born on August 3, 1950 in Phenix City, Alabama, and raised in Georgia. He deployed to Vietnam in 

July of 1970, and by March of 1971, like David, he was an experienced Morse intercept operator. Both men were 

passionate about their work and loved to fly. 

The unit’s general mission at the time was to provide support to both US and South Vietnamese forces in the 

area of operation. Like similar ASA units, the 371st was dedicated to gathering the critical intelligence required 

to allow coalition forces to gain an advantage in the battle space, and ultimately to save 

lives. The missions conducted combined highly skilled electronic direction finding with the 

lethal firepower of mobile airborne warfare. Airborne radio direction finding had distinct 

advantages over ground-based collection operations due to its ability to cover larger areas. 

The ultimate goal of the missions was to locate enemy units so that firepower could be 

brought to bear. This often times required the teams to “get in close,” so close, in fact, that 

the unarmed aircraft were often subjected to enemy fire. On this day, the crew’s specific 

THEY SERVED IN SILENCE

The Story of a Cryptologic Service and Sacrifice

Yellow Bird Down
MP 33610

objective was to collect intelligence related to the enemy activity near the portion of the Ho Chi Minh trail that 

ran through southeastern Cambodia. 

Due to the success of these flights, in February of 1971 the North Vietnamese had moved anti-aircraft weapons 

into the area. Approximately nineteen miles past the South Vietnamese border, near Dambe, Cambodia, the 

helicopter took a direct hit from a 37mm anti-aircraft gun. The blast blew off the main rotors of aircraft, causing 

it to plummet to the ground and explode. All four soldiers were killed in the attack. The next day, a South 

Vietnamese unit was able to reach the crash site and recover the remains of Uhl, David, and Sablan. No remains 

of WO1 Black were ever found. 

Both David and Sablan were beloved by their friends and families and highly thought of and respected by their 

compatriots. Teena Ligman, the wife of a family friend and fellow soldier David Ligman, noted that “My husband 

served with Gary ... the day he died, my husband had actually been slated to go up. Gary loved to fly and took his 

place ... my heart hurts for the sacrifice of all those who loved, or would have loved Gary David.” Frank Sablan’s 

sister noted on a digital tribute site, “You are in my thoughts and heart... I am proud of you and all that you gave to 

your country and family.”

Both men will be remembered for their courage, bravery, and devotion to their unit, their fellow comrades in 

arms, and ultimately, the nation that they served and died defending.