Another indication of the enemy's growing strength in I Corps came only two days later when a large Viet Cong force overran an ARVN outpost four and a half miles southwest of Tarn Ky. I Corps Headquarters quickly drew up plans for a multi-company search of the area even though the Communists had withdrawn from the badly damaged government position shortly after their final assault. At 0845, 18 Marine UH-34Ds (three armed) and four Army UH-lBs (two armed) helilifted a 208-man Tiger Force from Da Nang to Tarn Ky where it had orders to stage with other units for the operation. While the U.S. helicopters were in the process of transporting the Vietnamese troops to Tarn Ky, an aerial observer sighted a large formation of Viet Cong moving southwest from the scene of the previous night's battle. The observer immediately brought air strikes and artillery fire to bear on the enemy, blocking his escape.
Fircpower contained the enemy throughout the morning while the infantry units at Tarn Ky prepared to exploit the situation with a heliborne assault. The helilift was launched at 1345. En-route to a landing zone, located six miles southwest of Tarn Ky, the helicopter formation passed over the smoldering ruins of the ARVN outpost where ammunition stockpiles were still exploding. Once at the objective, the armed helicopters began delivering suppressive fire into the surrounding hedge rows and treelines as the troop carrying aircraft approached the landing zone. Still, after nearly six hours of air and artillery strikes, the Communist force was able to oppose the landing with intense small arms fire. No helicopters were hit during the landing, however, and the assault force managed to secure the landing zone. This accomplished, two companies from the llth ARVN Ranger Battalion were helilifted into the position without incident. After the final troop lifts, the Marine transport helicopters began evacuating casualties from the outpost where eight Vietnamese soldiers and one American advisor had died and 20 ARVN and an Australian advisor had been wounded.** The government's response to the enemy-initiated action, including air and artillery strikes, accounted for 70 Viet Cong killed and 39 weapons captured. While reflecting a moderate success, these statistics were little compensation for the knowledge that the Communists could destroy a well-fortified position within five miles of a provincial capital.7
Weather caused many Marine flights to be delayed and some to be cancelled during the closing month of 1964. But the interruptions were not frequent enough to prevent the task element from fulfilling its support commitments. The only type of support operation actually curtailed due to the monsoons was the pre-planned heliborne assault into the mountains. Brief periods of favorable weather usually enabled the Marine crews to accomplish resupply and medical evacuation missions even into the most remote areas of I Corps, although delays of such flights were not uncommon.
Lieutenant Colonel Koler's HMM-365 was past the midpoint of its assignment in Vietnam as 1964 drew to a close. Through 31 December the unit's helicopters had already flown over 6,700 sorties for a total of nearly 4,700 hours of flight time. Since its arrival in early October, Koler's squadron had distinguished itself not only by providing support to military units throughout I Corps but by its extensive participation in the flood relief operations of November and December. During the 30-day period after 10 November, HMM-365 had contributed a substantial percentage of its flights to the prolonged effort to rescue and evacuate Vietnamese civilians from flooded areas.8
FMFPac changed the designation of the task clement on the final day of 1964. From that date until mid-March of the following year the Marine helicopter squadron and its supporting elements in Vietnam would be known officially as Task Unit 79.3.5, Marine Unit Vietnam. This change, however, did not alter the existing command relationships. ComUSMACV continued to exercise operational control over the Marine task unit while the Commanding General, 1st Marine Aircraft Wing retained responsibility for its administrative and logistic support.
**[Note: March 9, 2015 Gary F. Janulewicz sent additional info for this section. He was involved in the assault and adds that Army SFC Fred C. Flowers, his advisory team member, was also wounded and eventually lost his leg as a result.]
Page 165 (The Advisory & Combat Assistance Era: 1954-1964)