Abstract: An arrangement for detecting and isolating leaks in a high temperature ducted flow system in which the fluid flow ducts are contained within duct insulation means which define an insulating air space around the ducts. The arrangement is configured such that in the event of a fractured or leaking duct, the leaking flow is contained within the insulating air space and constrained to flow to one pre-determined end of the duct system where it is ejected through a fluid outlet opening positioned in close proximity to leak sensing means. By this arrangement the leakage flow is cause to impinge on the leak sensing means enabling the leaking system to be effectively isolated.

Abstract: A fluid flow distribution duct for receiving temperature controlled air from duplicated Environmental Control System units in an aircraft air conditioning system and providing balanced distribution of the respective air flows to port and starboard sides of the aircraft cabin. The invention provides efficient separation and distribution of the respective flows, flow mixing occurring at or about the cabin inlet position. By this arrangement, the need for flow mixing chambers obviated giving a more efficient flow and compact duct arrangement than hitherto.