Operation Trail Dust
Operation Ranch Hand
1964-1966
With the approval of the State and Defense departments, the program was expanded. In January 1964 authority was delegated to division senior advisors for hand-spray operations. This was particularly useful in reducing the lag time that had existed from proposal to completion of small defoliation projects.
Ranch Hand aircraft were used mainly for Mule Train logistics missions and Tactical Air Positioning System (DECCA) tests from January to June 1964, although some defoliation missions in the Mekong Delta were flown during this time.
Due to heavy concentrations of Viet Cong (VC) in the delta area north and south of Ca Mau, Ranch Hand crews developed the "pop-up" delivery technique. This involved flying very low (20 feet above the ground) through open areas and then "popping-up" to 150 feet for the spray run over the target. However, increased hits from enemy ground fire caused reevaluation of these tactics, and a decision was made to schedule multiple targets. This permitted pilots to break-off from a hot target and spray one that was not so active. As an additional measure, the decision was made that no single target would be sprayed more than 2 days in succession.
From early July to 22 July 1964, Ranch Hand aircraft sprayed many targets in the delta region, defoliating VC safe havens such as the mangrove areas in the Go Cong Province.
During May 1964 pilots reported to Ranch Hand units on permanent change of station (PCS). During their first 2 and a half years in Southeast Asia Ranch Hand crews had been assigned for a 4-6 month TDY tour. In July 1964, the SASF was transformed into Detachment 1, 315th Troop Carrier Group, operating with the 309th Air Commando Squadron. C-123 Ranch Hand aircraft were modified to include a new-pump installation, permitting an increased flow rate of 3 gallons per acre.
Defoliation operations continued through the fall of 1964. On 3 October 1964 the Ranch Hand crews flew their first crop destruction mission under the Farmgate concept (utilizing mixed VNAF/USAF crews), which involved the major food producing areas adjacent to War Zone D (northeast of Saigon). This project, nicknamed "Big Patches," covered a period of 10 days and was highly successful.
During 1964, a total of 257.7 square kilometers of roads, railroads, canals, and VC base areas were defoliated and 15,215 acres of crops were destroyed. For their first 3 years, Ranch Hand flights primarily dispensed the Agent Purple herbicide. Nicknamed from the purple band painted around each 55-gallon drum containing the liquid, it was a commercially proven weed-control agent then in wide use throughout the world.
Ranch Hand operations continued to expand in 1965. Project 20-33 originally included 15 individual targets; 3 additional targets were added later. Targets were heavily foliaged areas along roads and railroad lines. Forty sorties flown during a 14-day period in January 1965 dispensed 36,600 gallons of herbicide. Forty-two additional sorties were flown from 1 March to 19 March 1965, delivering 27,000 gallons of herbicide. Also beginning in 1965, Ranch Hand crews began operating in support of jungle burning operations. These operations and the use of defoliants to help prepare target areas, continued into 1968.
Project Yankee continued with crop destruction in the "enemy rice bowl" of the northern coast, the An Lao Valley, Binh Dinh Province. Operations started on 27 March 1965 and ended on 18 April 1965. Thirty-seven sorties were flown, 27,300 gallons were dispensed, and substantial quantities of foodstuffs were destroyed.
Project Swamp Fox, the largest defoliation project to that time, was initiated on 30 April 1965. The targets included VC strongholds in the Bac Lieu, Ba Xuyen, and Vinh Binh Provinces. The project was 70 percent complete when it was terminated on 25 May 1965 because of heavy ground fire. However, 77,600 gallons of defoliant were effectively delivered during the operations.
Following Swamp Fox, a reevaluation of defoliation operations was conducted by MACV-J2 (Intelligence). The study concluded that defoliation missions were of considerable tactical value, but that operations were to be suspended on 30 June 1965 until additional A-lE crews could complete their training to fly escort for the C-123s. During this interlude Ranch Hand crews again flew cargo missions.
New crop denial missions were flown during the summer and fall of 1965 in Kontum and Binh Dinh Provinces, and on 20 October 1965 operations began in War Zone D. By 17 December 1965, 163 sorties had been flown and 137,650 gallons of chemicals had been dispensed. Fighter support for the spray aircraft included F-lOOs, F-5s, A-4s, and A-lEs. Defoliation missions with fire support were resumed in November 1965. They included targets along the banks of the Oriental River where 18 sorties were flown and 14,000 gallons of defoliant were dispensed. In December 1965, projects were initiated in Kien Hoa and Phuoc Tuy Provinces. In Kien Hoa 70,450 gallons of defoliant were delivered from 7 December 1965 to 31 May 1966. The Phuoc Tuy project began on 18 December 1965 and ended on 30 January 1966. By the end of the project 60,000 gallons had been dispensed.
Defoliation operations in Laos also began in December 1965 under the Tiger Hound program in the Steel Tiger (Panhandle) area of operations of Laos. These activities continued through 31 May 1966, by which time 250 sorties had been flown and most of Routes 92, 922, 96, and 965 had been defoliated. By 30 June 1966 approximately 1,500 kilometers of roads and trails in Laos had been sprayed to a width of 250 meters on either side. During this time period, 200,000 gallons of herbicides were dispensed.
Defoliation operations in RVN increased in 1966. During January 1966, 130 sorties were flown and 118,500 gallons of chemical were delivered in the Vung Tau, Bac Lieu, Saigon, Nha Trang, and Pleiku areas. In February 1966, 45 defoliation and 48 crop destruction sorties were flown in I Corps and 63 sorties in Laos. The total for February 1966 was 156 sorties, which dispensed 145,300 gallons of chemicals.
In March, April, and May 1966 more sorties were launched in Kien Hoa and Phuoc Tuy Provinces, as well as in Laos. During March, 116 sorties were flown in RVN and 47 in Laos dispensing 148,450 gallons of herbicide. In April 1966, the number of sorties flown increased by 20 percent, with a 4.4 percent increase in the amount of herbicide dispensed. These were to be delivered by the end of the calendar year. Chemical supplies were also increased to meet the expanded activity. Sorties flown in RVN during May 1966 totaled 218, and 199,450 gallons were delivered. In Laos, 23,700 gallons were dispensed in 24 sorties during May 1966.
From November 1965 onward, Ranch Hand had been using 7 aircraft. However, in April 1966, COMUSMACV decided to defoliate larger War Zones C and D areas and had requested 11 additional UC-123s. Eleven additional aircraft were programed for modification and assignment to the Ranch Hand unit in May 1966. Seven new aircraft were received on 10 October 1966, providing the Ranch Hand unit with 14 aircraft at Tan Son Nhut. Spray operations south of the Demilitarized Zone (DMZ) during the summer of 1966 were operating at a rate of 4 sorties per day. So many missions were being flown that the supply of herbicide ran low once again, and maintenance began to fall behind. The crews had to slow down to permit supply and maintenance to catch up.
Major modification of all spray aircraft was undertaken in July 1966. A new spray system, designated the A/A45Y-1 Dispenser System was installed. Some aircraft were delivered from the United States in 1965 and early 1966 with the new system already installed. This new system was capable of spraying 250 to 400 gallons per minute, which was sufficient to provide a coverage of 3 gallons of defoliant per acre under a variety of tactical conditions. The completed system had a 20-horsepower pump, which provided the increased spray capability and a 10-inch dump valve which improved the "quick dump" capability from 75 to 29 seconds during aircraft emergencies.
The first documented spray missions flown over North Vietnam occurred in the summer of 1966. Mission coverage ranged from the Mu Gia Pass southward through Laos into the A Shau Valley of South Vietnam. By the late fall of 1966, herbicide operations were being conducted in all Corps Tactical Zones of RVN.
On 15 October 1966, Detachment 1, 315th Troop Carrier Group (still being referred informally as the SASF) was assigned to the 12th Air Command Squadron after the 309th Air Commando Squadron was inactivated. The 12th Air Commando Squadron moved to Bien Hoa Air Base on 1 December 1966, where there was more room for storage and operation. During December 1966 and into January to February 1967, the main areas of activity were in War Zones C and D, as many as 29 sorties were flown daily.
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