UK Air Accident Investigators have released their preliminary findings into the Bond Helicopters EC225 ditching into the North Sea on February 18. The chopper, with 16 passengers and two crew aboard, was making its final approach to an BP-run production platform 120 miles east of Aberdeen. The report says there is no evidence of malfunction on any major mechanical components although investigations into avionics and warning systems are continuing. The report says that as the helicopter approached the rig, the weather quickly deteriorated. The visibility had reduced to 0.5 nm and the cloud base had lowered to 500 ft above sea level. The report states that: "at a range of approximately 13 nm, the commander could also see the platform and the crew agreed to descend to 500 ft asl and conduct a visual approach using the weather radar to assist with range information. The crew then elected to descend further, to a height of 300 ft asl, to ensure clearance from the reported cloudbase but on passing 400 ft the helicopter entered a bank of fog. The crew climbed the helicopter to 500 ft asl where they could again see the ETAP platform gas flare and platform lights, but not the helideck, which has an elevation of 166 ft.” The crew disengaged the autopilot just under a mile from the platform and a 'Check Height' audio warning was suspended. The helicopter commenced a turn to the left and began to descend and reduce speed. When it rolled out of the turn the visibility appeared to have reduced, but the crew could still see the bright glow of the platform flare. The co-pilot saw what he believed was the platform’s helideck lighting as well as the lights of the platform and the commander saw what he believed were the lights of the platform but could not identify the helideck. The aircraft made a heavy landing on the surface of the water.  Now, if at any time the pilots are uncertain about the location of an installation/vessel, a go-around is mandatory.