Lesson 6: Air Data Computers

Question 1

What is ADC used for?

Answer 1

• Accurately measure critical air mass properties
• Track pressure/temp.
• Signals for use by flight instruments, nav, and engine systems
• Predict capture points for autopilot

Question 2

What are the ADC Input Signals?

Answer 2

• Pitot Pressure
• Static Pressure
• Total Air Temp
• Angle of Attack

Question 3

What does SSEC stand for?

Answer 3

Static Source Error Correction

Question 4

What is the purpose of SSEC?

Answer 4

• Produce minimal residual static system error

- Corrects pressure Alt of ADC

Question 5

What can SSEC be influenced by?

Answer 5

• Current useful weight

- AOA

Question 6

What are the 2 types of ADC sensors?

Answer 6

• Absolute pressure sensor

- Differential pressure sensor

Question 7

What are the three common transducer designs for ADC sensors?

Answer 7

• Bonded Strain gauge
• Resistive elements
• Capacative elements

Question 8

What is the sensitivity for ADC sensor outputs/inputs?

Answer 8

Electrical output, Mechanical input

Digitized output for microprocessor

Question 9

What does RVSM stand for?

Answer 9

• Reduced Vertical Separation Minima

- operation between FL290 and FL410

Question 10

Define AOA

Answer 10

The ANGLE between the CHORD line of the wing and the relative motion of the aircraft

Question 11

Where are stall warning switches located?

Answer 11

The wing leading edge

Question 12

What is the Critical AOA of most airfoils?

Answer 12

15-20 degrees

Question 13

What does the AOA system do?

Answer 13

• Depict critical angles on approach/landing
• Stall warning
• Establishes attitude
• Verify airspeed indications/computations

Question 14

What are the 2 styles of AOA probes?

Answer 14

• Vane type (large airc,)

- Differential pressure sensing probe ( small airc.)

Question 15

Describe the Vane Style Probe

Answer 15

• Points to the direction of relative airflow
• Side of Fuselage
• Position is ELECTRICALLY sent to display
• Has moving parts

Question 16

Describe the Differential Pressure Probe

Answer 16

• Found below the wing
• Senses pressure through different holes
• Pressure sent to computer via pneumatic hoses
• No moving parts

Question 17

2 types of AOA transducer types?

Answer 17

• Hinged Vane

- Slotted Probe Types