Aircraft Systems Topic 18.
Central Air Data Computers (CADC's)
There are two Central Air Data Computers in most modern air
transport aircraft to provide redundancy
should one fail.As the name implies, they process all air type data which gets fed to the cockpit as electrical energy to show CAS, TAS, Mach number, altitude, and vertical speed. Refer to Fig AS13 below.
Fig AS 13 Central Air Data Computer inputs/outputs.
Your prayer wheel is a type of Central Air Data Computer. The same inputs are used to get the desired information out as by the CADC. Some examples of the inputs required for the various cockpit displayed data are shown in Fig AS 14.
This is a small sample from the Airspeed/Altimetry/ETP/PNR training manual (reference Av2) now available by secure credit card transaction from the online store, and pilot supply shops around Australia. This text is part of the distance learning ATPL training course, and will soon be available on CD-ROM, and via the internet.
ATPL training course information is also available within the Avfacts website.
Good luck with your studies, and remember...
Professional pilotís never stop learning !