The flight crew of an A340 landing at Nairobi (NBO) stated that they became visual with the runway at a height of 300-200 ft. At the decision height of 200 ft, both pilots could see all the approach lights and a good section of runway lights. The autopilot was disconnected at 100 ft radio altitude and the PF began to flare the aircraft. The aircraft floated at around 20 ft for a few seconds before it entered an area of fog and the PF lost sight of the right side of the runway and the runway lights. The commander also lost sight of the right side of the runway. The aircraft touched down normally on the main gear only. The commander was only aware of their position by the glow of the lights illuminating the fog. The commander called “GO AROUND” and the PF immediately advanced the thrust levers from idle to full thrust within one second. G-VAIR became airborne after a period of just under five seconds on the ground.
An inspection by airport staff confirmed the presence of a single set of landing gear marks off to the left of the paved surface. (AAIB)