Each engine is fitted with LP and HP bleed air ports located on the compressor HP spool. The main LP bleed ports supply air to the interconnection manifold, named the “distribution line” to which the main systems are connected. When the LP air pressure is not high enough to achieve correct anti-icing or defogging, HP air, extracted through the main HP bleed ports, is injected into the LP bleed air through an electric valve. The Bleed Air System Computer (BASC) controls the electric valve opening and closing. The BASC monitors the wings anti-ice system and displays the corresponding CAS message(s). Ice protection of engine air intakes is provided by HP air extracted from the corresponding engine through the auxiliary HP bleed air port.