A sad occurrence, which has happened on a a good number of occasions over the years going into LHR. Most of the occurrences happened in the Putney/Mortlake/Richmond areas, where descending aircraft seem to lower their wheels in preparation for landing. I don't recall ever hearing about bodies falling out over Windsor etc when the aircraft are landing from the West. Perhaps it's as previously said, that the more rural the approach, the less likely that the stowaway's body would be found , let alone noticed. Maybe bodies have fallen out over the brief moments the landing aircraft have been over the River Thames and have been reported at some later date as unknown, presumed drowned/murdered and disposed of ? In this day and age of technology would it be too difficult to install a small device that would be able to scan for anomalies (human/animal/insect) in the MLG area ?