domenica 26 maggio 2013

Avionics bending: Mach/Airspeed indicator

Hello everybody, following here is the pinout diagram of the 757 / 767 mach / airspeed indicator.

This is a very neat unit. It is powered at 115VAC 400Hz from Instruments Xfer Bus and it features dual source ARINC bus. The data in the plane come from the ADCs (Air Data Computer) which compute various parameters such as static pressure, dynamic pressure, altitude and Others and compute the arinc words to drive the gauge for the following functions:

- Airspeed
- Barber Pole
- Mach number

The Speed command bug is also in ARINC format and is directly driven by the MCP (Mode Control Panel)

Here are shots and a small test video of the unit. Enjoy!