The Captain of the aircraft contacted PMI ATC on decent to advise them that the engine would produce a lot of smoke on touch down and that this was normal on this aircraft and was not an emergency! So why the fire brigade took it as an emergency is beyone me. Unless ATC hadn't communicated with the fire brigade.
Even the pax were told that smoke would come from that engine but that it was normal. The A/C is still in PMI!