Patent ID: 8413930

Claim:
An air intake duct for use in an aircraft, the duct comprising: a toroidal leading section having a toroidal plenum defined by an outer skin of the duct and an internal bulkhead; an inner skin defining a toroidal air flow channel extending, within the plenum, over a portion of the outer skin thereby defining a double walled skin section of the plenum, the inner skin encompassing a zone of variation of the position of the stagnation point of the airflow over the outer skin over the flight envelope of the aircraft and the plenum having another skin section which is single walled; an inlet for supplying hot air to the plenum; an inlet for supplying the hot air to the channel; and an outlet for venting air; wherein the toroidal air flow channel forms a substantially continuous toroidal air flow space and wherein one end of the inner skin is supported by a first support and another end is supported by a second support, the inner skin being moveable relative to one of the supports.