MACH/IAS INDICATORS.

Mach/IAS indicator

Indicated speed (IAS) 250 kt. Mach .43
Speed is limited by IAS. 		Mach/IAS indicator

Indicated speed (IAS) 300 kt. Mach .76
Speed is limited by Mach number.


The two Mach/IAS indicators are installed one on each flight instrument panel. Each indicator has an integrated display of IAS, Mach number and maximum operating limit speed. Mach is indicated by the speed pointer on a moving scale ranging from 0.4 to 1.0 Mach. Indicated airspeed (IAS) is indicated by the speed pointer on a fixed dial ranging from 60 to 400 kt. The Mach scale is viewed through a cut-out in the fixed dial.

VMO (Max IAS) is indicated by a red and white radial on the fixed dial. MMO (Max Mach number) is indicated by a red and white radial on the Mach scale.

The indicator also includes a speed index which is controlled by the knob down in the lower right corner. The speed index is used as a reference only. It is not possible to use this index to set the speed of the autothrottle. The index is normally set to V2 during takeoff and to Vref (threshold speed) during descend and approach. Speeds to be found in the speed booklet.