 The main evacuation occurred in the early morning hours of 6 January and consisted of four waves of five CH @-@ 46 helicopters . The timing of this phase was determined by range of the CH @-@ 46 Sea Knight , which lack aerial refueling capability ; the ships were about 350 – 380 nautical miles ( 650 – 700 km ; 400 – 440 mi ) away during this phase . An AC @-@ 130 was sent from Saudi Arabia to provide gunfire support during the evacuation and two UH @-@ 1 Iroquois helicopters were on standby to provide gunfire support , but were not deployed . 
