10 Autopilot

Question 1

What are the different Autopilot channels?

Answer 1

• Roll
• Pitch
• Rudder

Question 2

With regards to the autopilot, describe the Inner Loop

Answer 2

• Inner Loop provides control and stability of the AC
• Manipulates the control surfaces in order to control the AC attitude
• Attitude is maintained against a datum

Question 3

With regards to the autopilot, describe the Outer Loop

Answer 3

• Outer Loop provides guidance of the AC

- Updates the datum by which the Inner Loop works against

Question 4

With regards to the autopilot, describe a Closed Loop including the downside of using it

Answer 4

• A Closed Loop provides feedback from the control surface vs the input control
• Provides a measured response
• The type of loop used for the AP system
• Can cause self induced oscillations

Question 5

With regards to the autopilot, describe an Open Loop

Answer 5

• Open Loop provides no feedback
• Only aware that a control surface is moving
• Not suitable for an AP system

Question 6

What is an Actuator?

Answer 6

An Actuator is a mechanism for converting an electrical signal to a mechanical movement

Question 7

What does it mean if the Actuators are in:

• Series
• Parallel

Answer 7

• Series: Movement of the control surface is not replicated by the control column
• Parallel: Movement of the control surface is replicated by the control column

Question 8

With regards to the AP, what is Automatic Synchronisation?

Answer 8

• Process by which the AP system follows the pilots inputs, ready to take over when required
• Ensure a smooth engagement of the AP
• Operates whilst the AP is disengaged
• Requires the AC to be in trim to allow engagement

Question 9

What is Autotrim?

Answer 9

• Operates whilst the AP is engaged
• AP system constantly trims the AC during flight
• Ensures a smooth disengagement of the AP
• Prevents ‘snatching’ of the controls
• Use of manual trim leads to the disengagement of the AP

Question 10

With regards to Autopilot, what is Control Wheel Steering (CWS)?

Answer 10

• Allows the pilot to manually fly the AC with the AP still engaged
• Uses AP actuators
• Modes for roll or pitch can be selected
• FMA mode must be re-selected after

Question 11

With regards to Autopilot, what is Touch Control (Wheel) Steering (TCS / TWS)?

Answer 11

• Allows pilot to manually fly the AC with the AP still engaged
• Uses the normal actuators
• AP goes into a ‘Pause’ mode
• Reverts to the previous mode after

Question 12

What is the ‘very’ basic function of the Autopilot?

Answer 12

To stabilise the AC around it’s CoG

Question 13

When crossing the cone of confusion of a VOR, what does the Roll channel of the Auto Pilot do?

Answer 13

• The Over Station Sensor detects the AC is over the station

- The Roll channel switches to Heading mode temporarily maintains the heading

Question 14

If a pilot engages Control Wheel Steering (CWS) and carries out a manoeuvre in roll, when the control wheel is released what will the auto pilot do?

Answer 14

Maintain the the flight attitude obtained at that moment

Question 15

If the automatic synchronisation of the AP fails what happens?

Answer 15

The AP will be prevented from engaging

Question 16

What are the basic AP modes?

Answer 16

• Pitch attitude hold

- Horizontal wing hold

Question 17

What are the vertical flight path modes of an autopilot system?

Answer 17

• FMS vertical navigation
• Flight path angle hold
• Glide slope intercept and track
• Altitude hold

Question 18

Among other parameters, which of the following are used by the Auto Pilot system:

• Altitude
• Attitude
• Vertical speed
• Inertial position
• Temperature
• CAS
• GPS position
• Fuel Flow
• Heading

Answer 18

• CAS
• Altitude
• Attitude
• Vertical speed
• Heading