Abstract: An aircraft nacelle air inlet comprising: a lip skin defining a curved surface of the inlet, the curved surface extending about a longitudinal axis of the inlet; a forward bulkhead; an inner barrel having a radially inner surface defining a surface of the inlet, a radially outer surface, and a sound attenuating layer arranged between the radially inner and radially outer surfaces; and a joining frame fixed to the lip skin and/or to the forward bulkhead. A first portion of the joining frame extends over at least a portion of the sound attenuating layer of the inner barrel and is fixed to the radially outer surface of the inner barrel.