A plane can carry a maximum of 4.5 hours of fuel. When the plane takes off from the airport to perform a mission, it goes with a downwind and flies 800 kilometers per hour; when it returns with a headwind, it flies 640 kilometers per hour. , what is the maximum distance in kilometers from the airport?
一架飞机携带的燃油最多能飞行4.5小时，飞机从机场起飞去执行任务，去时是顺风，每小时飞行800千米；返回时是逆风，每小时飞行640千米，这架飞机执行任务时，飞离机场的最大距离是多少千米？
<gadget id="calculator">800 + 640</gadget>
<output>1_440</output>

<gadget id="calculator">4.5 / 1_440</gadget>
<output>0.003125</output>

<gadget id="calculator">640 * 0.003125</gadget>
<output>2</output>

<gadget id="calculator">800 * 2</gadget>
<output>1_600</output>

<result>1_600</result>