A320 Upper Riser Duct Outlet Cleaning

The air outlet area above the overhead stowage bins is as dirty as the riser ducts inside. The black residue is not dust, but results from oil leaking in the engines. The oil gets pyrolized (burned) and finds its way into the cabin with the high pressure "bleed air" taken off the engines for cabin ventilation.

For more information: http://CabinAir.ProfScholz.de