They only fly over harlow when outbound not inbound at LHR
so I douht I will see this again, the sound its engines made caused me to look up as I could hear it was odd. Harlow is also the fligut path for STN
approach at around level 3000 so I hear planes all day but this sound was strange plus gear was down.
[Edited 2013-08-05 13:05:09]