At the beginning of 1966, the unit found itself in a less than desirable situation. Because of the size of its 18 Caribou and the ramp space required for parking and maintenance, the company was divided between Soc Trang and Can Tho in the Delta region of Vietnam. The Company headquarters, 260^th Maintenance Detachment and the second platoon with nine aircraft were stationed at Can Tho. The first platoon with nine aircraft and a small maintenance section were located at Soc Trang, roughly 30 miles away. Living conditions at Can Tho left much to be desired. The crewchiefs were living in a tin shed with a dirt floor at the airfield and the remainder of the enlisted personnel were living on the 5th floor balcony at the Delta Hotel, while the pilots were living in three different locations. Soc Trang living conditions were crowded, but at least everyone was living at the compound, within walking distance of the flight line, mess hall and billeting area.

After the 80 hour flight from Fort Benning to Vung Tau, all of the aircraft were due a periodic inspection and most of January was spent performing maintenance while the unit waited for its equipment to arrive. Even though the 134^th didn't become fully operational until 1 February 1966, it flew 744 sorties during January, delivering 450 tons of supplies and equipment and transporting over 5,000 passengers.

Living conditions in Can Tho improved on January 28^th when the unit moved into its own four story hotel downtown. The first floor was used as an orderly room and small COLA mess. The enlisted men were housed on the second and third floors and the officers occupied the fourth floor. The chain of command at the start of the year was Major Ted N. Phillips, Commanding Officer, Captain Raymond J. Riticher, Executive Officer and Captain Gary O. Alton, Operations Officer. There were many different types of missions but the primary one was to support the 5^th Special Forces in the Delta.

On 6 February an aircraft performed an emergency medical evacuation, under extremely hazardous conditions, of one American and six seriously wounded ARVN soldiers from Phu Quoc Island, flying them to the hospital at Saigon. Had the Caribou not flown this mission several of the wounded would not have survived. Also during the month of February, 134^th aircraft transported over 3,000 troops in support of tactical operations within IV Corps. Of the total cargo delivered, 1,322 tons were air landed, 47 tons were air dropped and 38 tons were delivered by low level extraction. During the month the unit had seven aircraft hit by ground fire, two of which sustained major damage.

By March, after two months of combat flying behind them, local commanders had been shown what the Caribou could do for them. Due to a large backlog of supplies and equipment to be delivered the unit was taxed to the maximum. Crews were flying from daylight to dark, seven days a week. Landing at remote strips with no radio contact and being recalled from scheduled missions to participate in a tactical emergency were getting to be everyday occurrences. During the month, the 134^th moved over 5200 troops in tactical operations.

On 23 March 1966, after completing a full day's flying, the unit was called on to airlift a Ranger battalion from Can Tho to Soc Trang at night. Aircraft 62-4165, after being cleared to land by the tower, collided with a VNAF H-34 whose rotor blades were overlapping the runway. The helicopter was a total loss and the left wing of the Caribou was damaged, but there were no injuries. The wing was changed on the Caribou and it was flying again within a week. During one week in March, the unit carried over 3,000 troops in support of combat operations in the IV Corps area. In this same week ARVN troops killed over 800 Viet Cong by body count.

May was a bad month for the Rough Riders. On 10 May 1966, aircraft 62-4165, while on a Special Forces airdrop mission at a remote camp at Cai Cai, had a load of rice hang in the rear of the cargo compartment on a low level extraction causing the aircraft to crash. The pilot and copilot (Cpt. Gil Roessler and CW2 Joe Hudson) escaped with serious injuries, but the flight engineer, SP5 Herbert N. Adams, and the Special Forces rigger on board were killed on impact. A few days later, another aircraft had a left main landing gear collapse on landing at Bien Hoa. There were no injuries but the aircraft was down for about a month for repairs.

On 18 May 1966 Soc Trang Army Airfield (AAF) was the target of a mortar attack and three Caribous were damaged. One aircraft received 76 holes from shrapnel. On the same day at Can Tho the new living quarters at the airfield were completed and the crewchiefs were the first to move in. On 29 May, the 134^th NCO Open Mess opened and served three hot meals a day. Breakfast was 40 cents and dinner and supper were 75 cents. Everyone in Can Tho was drawing COLA (Cost of Living Allowance) because no class A mess halls existed in the Can Tho area.

On 31 May 1966 Major Robert L. Landry replaced Major Ted N. Phillips as Company Commander. Major Phillips had commanded the unit for over a year.

June found the unit well on its way into the monsoon season. Already many of the strips in the low lying areas were closed and slowly going under water. While on a Special Forces mission to Don Phue one crew landed at a strip that appeared to be firm but with a few scattered water spots. However, after landing the crew found the water to be knee deep on portions of the strip. The cargo was unloaded and when the crew attempted to take off the propellers picked up enough water to drown out the engines. A maintenance team had to be sent in by helicopter to dry out the carburetors but the crew had to wait until the next day to take off, after the water had receded.

In July, the first platoon at Soc Trang learned that children of the local ARVN 212^th Artillery Battalion needed additional school classrooms and they undertook the project in their spare time. Plans were drawn, the material obtained, and the platoon worked along with the men of the 212^th Artillery Battalion to construct the school. The building was completed just one day prior to the opening of school. In appreciation, a dedication was held on opening day to name it The Delta Rider School.

In early August the 134^th was notified of Operation Red Leaf, the transfer of the Caribous to Air Force control. On 13 August Major John F. Tiernan arrived as the first Air Force replacement. Major Tiernan's blue uniform put him on the receiving end of considerable ribbing but his good nature and quick wit soon made him a regular member of the unit. Shortly thereafter, every conceivable type of Air Force pilot showed up to be transitioned into Caribous (B-52, F-100, F4C, Reconnaissance, etc). Surprisingly, the transitions went smoothly. Also in August aircraft 63-9740 crewed by SP6 Thomas Dawkins and SP5 Harry Tiger Colly set a new Caribou record by flying 170 hours during the month.

Unfortunately the Air Force never flew the Caribou like the Army. They were primarily interested in long-range throughput missions while the Army used the Caribou for local support to remote Special Forces camps and similar missions. After the Air Force takeover, this incredible short field aircraft was phased out in favor of larger, high-speed conventional air transports. Consequently, the Special Forces and others were left without support. This was a role subsequently assumed by helicopter units.

More and more Air Force officers and enlisted men began arriving in November and living quarters again became a problem. Air Force and Army personnel now worked side by side. By this time almost everyone who came over with the 134^th had reassignment orders and the old saying of Happiness in Vietnam is DEROS was finally coming true. The first large group of officers and enlisted men left on the 17^th of the month, leaving only a small number of Army personnel remaining.

Also in November, Aircraft 61-4161 struck a mound of dirt with the left gear causing major damage while on a Special Forces low level extraction mission. The aircraft landed at Bien Thuy Airfield with no injuries to the crew. The left main gear was replaced and the aircraft then flown to Vung Tau for more repairs.

By the beginning of December only a few key Army personnel were left and the Air Force take over was almost complete. The remaining Army personnel were kept busy with the final phases of deactivation. The Air Force was confronted with the problem of moving the entire unit from Can Tho and Soc Trang to their new home at Cam Ranh Bay. The last Army pilots in the unit flew Operation Rudolph on the day before Christmas and air-dropped a Christmas package to every Special Forces camp in IV Corps. The last officer to sign out of the 134^th Aviation Company was LTC Robert L. Landry. During the company's tour in Vietnam, it carried 13,700 personnel on troop lifts, flew 26,170 sorties, carried 15,244 tons of cargo, 165,010 passengers, performed 620 medivacs and flew 13,710 hours. The 134^th Aviation Company was deactivated at Cam Ranh Bay on 1 January 1967.