Here is a screenshot of the approach to runway 9L at Heathrow. It is quite common for the B752 to have INS errors which mean the aircraft plots in the wrong place. Here two B752s which are both physically positioned on the centreline of 9L. Due to the INS broadcasting incorrect position data the Icelandair is showing about 5 miles SW of its actual position and the Uzbek is showing about a mile northeast of its actual position.