The weather in Fredericton was difficult—reported weather gave of vertical visibility and 1/8 of a mile in horizontal visibility. With the runway lights, the runway visibility was for landing on runway 15. At above ground level the captain approved the landing and the first officer, who was the pilot flying, responded that he would land the plane. Once the first officer disengaged the autopilot the aircraft drifted off the centre line of the runway and as the plane approached above ground level the first officer reduced the engine thrust to idle speed. The captain, knowing the plane was off centre and unsure how much runway was left, ordered a go-around.