Southend today

What on earth flew out of Southend today, came over Isle of Grain mid morning.
I’m putting this in historic because the amount of smoke out the back it must have been knocking on a bit. difficult to judge size but it was one eleven / VC10 rear engine kind of layout. I havn’t seen so much brown smoke in a long time, half expected it to head back to southend.
Anyone know?
Terry