Abstract: A system for circulating heated gases within the circular leading edge of a jet engine housing to prevent ice build-up thereon, or to remove accumulated ice thereform. Hot gases such as air from a hot, high pressure section of the jet-engine are directed through a conduit. The conduit enters the annular leading edge housing, usually from the aft side through a bulkhead, then turns about 90.degree. to a direction tangential to the leading edge annulus. The hot gases exiting the tube entrain the cooler air in the housing, causing a much larger mass of air to swirl circularly around the annular housing. The entering hot gasses heat the mass of air to an intermediate, but still relatively hot, temperature. This large mass of circularly moving hot air is quite efficient in uniformly transferring heat to the skin of the leading edge without leaving any relatively cold areas and preventing the formation of ice thereon.