ABOUT OPERATION RANCH HAND VIETNAM
SOUTHEAST ASIA 1961-1971

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Herbicides

.On Nov. 30, l961, President Kennedy accepted the joint recommendation of the State Department and Pentagon that the US proceed with a limited herhicide effort characterized by discriminate target selection and execution.
    In response, Tactical Air Command sent six C-123s to Olmstead AFB, Pa., for required reconfiguration. At Olmstead,
the airplanes were equipped with MC-1 tanks and stripped of all unnecessary equipment. They were fitted with an engine oil supply replenishment system. Spray booms were installed along trailing edges of the wing. Later, they went behind the tail.
    In early December 1961, with all C-123s having received their planned equipment changes, the aircraft redeployed to Clark AB in the Philippines. The long-distance flight proved the capability of the C-123. On Jan.7, 1962, three C-123s were deployed to Tan Son Nhut in Vietnam as a part of the 346th Troop Carrier Squadron. The sensitivity of herbicidal warfare became apparent. Despite urgent pleas from the field, officials debated at length whether the C-123s should be disguised with South Vietnamese insignia and flown by USAF crews in civilian clothes. As the origin of the aircraft could not be denied, this idea was abandoned. Also serving to delay full implementation of the program was the fact that local  stocks of herbicide were limited.
    The delays disconcerted the  Ranch Hand crew members, all of whom were volunteers. They found them-selves quartered in a tent city with-out much to do,

their aircraft parked in the same secure area at Tan Son Nhut that housed President Diem's squadron of fighters commanded by Lt. Col. Nguyen Cao Ky. While Ranch Hand had bosses at many levels - TAC, 2nd Advance Echelon, Military Assistance Advisory Group Vietnam, 13th Air Force, and Pacific Air Forc- es  it had little supervision. Few at any level of command knew how to execute the mission or how to evaluate its results.


Self-Taught
Fortunately, Ranch Hand crews knew they had much to learn and much to do. There were no tactical manuals and no doctrine for herbicidal warfare. They knew virtually nothing about how the various types of trees and other vegetation would react to herbicide. Nor did they know the quantity per acre of herbicide that would be required. Maps were few, intelligence was lacking, weather briefings were inaccurate, and no one was sure how to solve the operational problems posed by wind, temperatures, and terrain. Moreover, the prospective degree of enemy opposition was a totally unknown factor.
     
  On Jan. 13, 1962, Marshall formally initiated the Ranch Hand program. He and Capt. William F. Robinson Jr. took off and sprayed along Route 15, flying at 150 feet altitude and at a speed of 130 knots. Also on board were a flight mechanic, an Army scientist, several  observ- ers, and the required Vietnamese "aircraft commander."

   The first series of missions went well, as the Ranch Hand crews began teaching themselves their business. The pilot flew with both hands on the yoke, maintaining vertical and horizontal spacing in formation, and controlling the spray pump with a switch. The copilot maintained fore-and-aft spacing, monitored the airspeed and altitude, and stood ready to execute the emergency procedures or to take the controls if the left-seater was injured. An aircraft commander soon became one with the airplane, flying with his eyeballs and the seat of his pants because there was little time to look at the instruments.
The Ranch Hand crews quickly learned the necessity of surprise. To avoid small arms fire, they made their approaches to the target at 3,000 feet altitude. At a precomputed point, the C-123 would enter a steep, 2,500-feet-per-minute dive, pulling out at 150 feet. At that point, the crew would turn on the spray equipment and let it run for about four-and-one-half minutes. lf everything worked as planned, the airplane would lay a swath of herbicide 240 feet wide and 8.7 miles long.
Then the C-123 would make a steep climb to get out of the range of ground fire.
   Ranch Hand pilots flew missions in formations of two or three ships in the early days and as many as 10 in the latter stages of the program. Some targets required sharp turns, and the turns required the aircraft to stack up in a "piggyback" formation to avoid being run into the ground.
     Later, when crop destruction missions were flown, tactics changed. Exposure to enemy fire could last as long as 45 minutes, compared to about eight to 10 minutes on defoliation runs.
     Crews soon learned that they had to spray in the early morning, when ground temperatures did not yet ex-ceed 85 degrees. Once the temperatures went higher, the spray would rise rather than drop to earth. Wind also could be a major problem. If its speed exceeded 10 miles per hour, herbicides woul'd be dissipated over an overly large area and have little effect on vegetation.

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