Impressions of the A320 Rudder System with Scenario Examples

• Rudder pedals mechanically linked to hydraulic actuators
• Not linked directly to the rudders
• Artificial feel unit interfaces with the rudder pedals
• When FAC provides turn coordination or yaw damping the pedals do not move
•Rudder pedals move if manually trimmed by the pilot
•Rudder pedals move if autopilot trims the rudder
•Rudder pedal position stay at the last trimmed position after autopilot disconnect

Airbus Normal Law
• Autopilot not engaged
• Pedestal Rudder Trim (Left or Right)
• Rudder pedals will trim to the position at 1 degree/second
• Pilot can be ”feet off” and the aircraft will remain at the trimmed position

Rudder Forces

AAIB Bulletin: 8/2008; Airbus A319-131,G-DBCI Incident
Submission of American Airlines, INC. To the National Transportation Safety Board
Accident Involving American Airlines Flight 587 At Belle Harbor, New York
November 12, 2001

Scenario 1
•Cruise altitude, Autopilot (AP) engaged
•The Aircraft follows the FMGS and the plan route
•Turn coordination of the aircraft is directed by FAC and performed by the yaw damper
•There is no physical movement of the rudder pedals

Scenario 2
• Aircraft on climb, AP not engaged
• One engine inoperative
• Pilot Flying (PF) takes immediate action with rudder input to compensate for the yaw shift
• Aircraft is manually trimmed with the Rudder Trim switch on the pedestal
• Control loading on the feet decreases as aircraft is manually trimmed until no further rudder input by the pilot is required
• PF can have ‘feet off’
• Autopilot engaged
• Rudder pedals remain in physical trimmed position and will move depending on the Autopilot, reflected in the rudder trim indicator

Scenario 3
• Aircraft in cruise, AP engaged
• One Engine Inoperative
• No pilot rudder input observed
• AP is engaged and will appropriately trim the aircraft as reflected on the Rudder Trim indicator on the pedestal
• Rudder pedal movement observed

Scenario 4
•The aircraft is on final approach with strong crosswinds
•The force of the winds reflected on the rudder of the aircraft does not feedback to the rudder pedals •Crab/Slideslip technique to land the aircraft; downwind rudder applied to eliminate the crab 

Scenario 5
• The aircraft is accelerating down the runway for take off
• As the velocity of the aircraft increases the pilot input to the rudder system also proportionally changes
• At high speeds rudder effectiveness increases

** Disclaimer: Information derived from observations in a Level-D A320 simulator, engineers, professional pilots and the FCOM; it could be wrong and obviously should not be used as a reference for real world training

3 thoughts on “Impressions of the A320 Rudder System with Scenario Examples

  1. Hello, which feedback system are you using? I have read that Brunners works great with Prosim. Is this rudder trim function (pedal movement) handled by Prosim?
    Thank you

    Like

  2. Pingback: Rudder Control Loading and Trim | Soarbywire

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