09 Air Data Computer (ADC)

Question 1

What is the purpose of the Air Data Computer?

Answer 1

Air Data Computer centralises the collection of sensed data and distributes it to the required outputs

Question 2

Describe the two types of Air Data Computer

Answer 2

Analogue:
- Inputs are collected from analogue sources which are then computed by electromechanical means and output to the different analogue outputs

Digital:

• Inputs are collected from both analogue and digital sources.
• The analogue sources are converted into digital signals using Analogue to Digital Converters (ADC’s)
• The ADC then processes the inputs and sends them to the different digital outputs

Question 3

What is the advantage of Digital systems compared to Analogue systems?

Answer 3

Digital is less susceptible to corruption

Question 4

What are the inputs for the Air Data Computer?

Answer 4

• Static Pressure
• Pitot Pressure
• Measured Temperature (RAT)
• Angle of Attack
• Weight on Wheels
• Configuration
• Stored Data (e.g. recovery factor)

Question 5

What is the nemonic used to remember the inputs for the Air Data Computer?

Answer 5

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Question 6

What are the outputs of the Air Data Computer?

Answer 6

• IAS and TAS
• OAT and TAT
• Mach Number
• Angle of Attack
• Altitude
• Vertical Speed
• Vmo and Mmo

Question 7

What is the nemonic for remembering all of the outputs of the Air Data Computer?

Answer 7

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Question 8

How many ADC’s will a small AC and a large AC typically have?
What else will an AC have if it only has one ADC?

Answer 8

• Small AC will typically have 1 ADC
• Large AC will typically have at least 2 ADC’s
• AC with only one ADC will have backup pressure instruments

Question 9

What systems use the outputs from the ADC?

Answer 9

• Primary Flight Instruments
• Transponders
• Auto-pilot and Flight Director
• Flight Management System (FMS)
• Flight Data Recorder
• Warning Systems