Adirs
Joined: Jul 1999
Posts: 134
Likes: 0
From: Big Sky Country
On the 777, the ADIRU is one unit which handles all pitot-static info while providing all the usual stuff you would expect from an IRU. It has 6 layers of redundancy, "talks" with dedicated ARINC 629 buses...the bottom line is where there were several boxes, now there is only one!!
Joined: Feb 2002
Posts: 554
Likes: 0
From: The Sandpit
IRS/ADC systems use a separate IRU and an ADC which is connected to lots of pipework so that pitot and static pressure can be sensed.
ADIRS's have a combined ADC/IRS and is fed pitot and static pressure from several Air Data Modules ADM's (1 pitot and 2 static ADM's per system). The main advantage is the removal of pitot and static pipework which can be prone to damage, blockage, water accumulation and it can be very labour intensive finding the location of these faults when they have occured.
ADIRS's have a combined ADC/IRS and is fed pitot and static pressure from several Air Data Modules ADM's (1 pitot and 2 static ADM's per system). The main advantage is the removal of pitot and static pipework which can be prone to damage, blockage, water accumulation and it can be very labour intensive finding the location of these faults when they have occured.
