Operation Billings commenced on 12 June as 1st Infantry battalions moved progressively north of Phc Vnh, then on the morning of June 17 preceded by a moving barrage, the 1st Battalion, 16th Infantry Regiment, failed to enter the LZ X-Ray.
On the morning of 17 June preceded by a moving barrage, the 1st Battalion, 16th Infantry Regiment, entered LZ X-Ray. 
