Cavalry (-) constituted the hammer forces that on D plus 1 would drive north into the horseshoe to locate and destroy enemy forces and facilities.

Both the Tropic Lightning Division and the Big Red One started deploying forces for JUNCTION CITY on 18 February (D minus 4) and were ready to roll by D-day.

D-Day, 22 February 1967

On D-day the operation order was implemented as envisaged. Nine infantry battalions conducted air assaults (eight airmobile, one parachute) to cordon the entire northern portion of the objective area. At the same time, the 25th Division adjusted its one brigade in blocking positions on the west while positioning additional units for the attack into the horseshoe; the 3d Brigade, 1st Division, pushed- north up Provincial Route 4 to complete the horseshoe.

The 1st Brigade, 1st Division, initiated the airmobile operations from Minh Thanh with one battalion making an airmobile assault at 0813 into a landing zone north of Route 246 and only 1,600 meters south of the Cambodian border. Sporadic small arms fire was encountered from the southern portion of the landing zone; however, the zone was quickly secured. The other two battalions of the brigade air assaulted into LZ's to the west of the first battalion at 1130 and 1630. They were unopposed.

Earlier that day, 845 paratroopers had boarded sixteen C-130's at Bien Hoa and at 0900 the 173d Airborne Brigade began its combat jump. As the aircraft approached the drop zone (three kilometers north of Katum), the jumpmaster's voice rose above the roar of the C-130: "Stand in the Door." General Deane moved to the right door; taking his position in the left door was Lieutenant Colonel Robert H. Sigholtz, commander of the airborne task force composed of the 2d Battalion, 503d Infantry; A Battery, ad Battalion, 319th Artillery; and elements of the 173d Brigade headquarters and headquarters company. As the green light flashed "go," General Deane jumped, leading the first U.S. combat parachute assault since the Korean War. There was no enemy contact during the jump.

(Chief Warrant Officer Howard P. Melvin of San Francisco, California, then 53 years old, was participating in his fifth combat parachute assault over a period of some twenty years. His previous four were Gela, Sicily, Salerno, and St. Mere Eglise.)

By 0920 all companies had established command posts. A heavy equipment drop commenced at 0925 and continued periodically