 However, a brush with a Royalist outpost at 0600 hours brought on the battle.With an overcast of 500 meters or lower, and mountain peaks poking into the clouds as a flight hazard, it appeared that Vang Pao's Auto Defense Choc (ADC) guerrillas would have to fight without air support.Communist troops closed within 100 meters of the Royalists; they broke into the Royalists' final defense line on the north perimeter at 0630 hours.