A strong history The heritage of THOMMEN AIRCRAFT EQUIPMENT Ltd. reaches far back when it was founded as REVUE THOMMEN AG in 1853 as a watc...
The THOMMEN MD21 Electronic Standby MACH Airspeed Indicator is highly reliable and indicates airspeed and MACH number with upmost accuracy. It is a direct replacement for mechanical standby airspeed indicators.
It measures pitot and static pressure with proven integrated solid state pressure sensors and displays the computed airspeed by an analogue pointer and a sunlight readable digital Liquid Crystal Display.
The MD21 Electronic Standby MACH Airspeed Indicator has a range of 0 to 450 knots and 0 / 0.200 to 0.999 MACH. VMO/MMO over speed warning is provided by a LED in the bezel.
It is designed to operate from 28 VDC primary power. LED-Lighting is controlled by an external 5 VDC (28 VDC optional) voltage. The lighting is available in white. Discrete outputs are available as an option. The RS-232 serial interface provides communication for maintenance and parameterization. An extensive Built-In-Test function guarantees safe operation.
The THOMMEN MD21 Electronic Standby MACH Airspeed Indicator is certified to ETSO/TSO-C2d, ETSO/TSO-C46a and ETSO-C95/TSO-C95a. It is tested to DO-160D and DO-178B SW level A.