W DOC AIRBUS | TSM A320F

Identification of the Cause of In-Flight Airframe Vibrations and/or Noises

TASK 05-50-00-810-801-A
Identification of the Cause of In-Flight Airframe Vibrations and/or Noises

1. Possible Causes

2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
TSM TASK 27-10-00-810-835-A
Airframe Vibration due to the Aileron
TSM TASK 27-10-00-810-840-A
Aileron Oscillations
TSM TASK 27-20-00-810-802-A
Airframe Vibration due to the Rudder
TSM TASK 27-20-00-810-808-A
Rudder Oscillations
TSM TASK 27-30-00-810-849-A
Elevator Oscillations
TSM TASK 27-30-00-810-850-A
Airframe Vibration due to the Elevator
TSM TASK 27-54-00-810-801-A
Flap Vibration
TSM TASK 32-20-00-810-803-A
Vibrations Felt during Climb because of Incorrect Clearance of the NLG Aft Doors
TSM TASK 52-11-00-810-826-A
Vibrations and Noise in the FWD Passenger/Crew Door Area
TSM TASK 52-13-00-810-826-A
Vibrations and Noise in the Aft Passenger/Crew Door Area
TSM TASK 53-35-00-810-801-A
Vibration and/or Noise felt in Mid Cabin
F Vibration Reporting Sheet
F Process for the Identification of the Vibration Source
F Decision Tree
F Decision Table
F Example of How to Use the Decision Tree
F Example of How to Use the Decision Table
3. Fault Confirmation
Subtask 05-50-00-710-077-A
A. How to Use the Vibration Reporting Sheet (VRS)
F Vibration Reporting Sheet
NOTE: It is necessary to print all of paragraph 3.A. to use the Vibration Reporting Sheet during flight.
The Vibration Reporting Sheet is divided into four main parts.
A description of the four parts of the VRS is given in the paragraph that
follows.
The flight crew must complete these parts when time is available and as permitted by flight conditions.
NOTE: When flight conditions make it necessary, the flight crew will try to stop the vibrations for passenger comfort. Almost always, it will be sufficient to decrease the speed and change the altitude.
   (1) Record the flight conditions when the vibrations occur.
These include:
  • The aircraft weight
  • The flight phase
  • The Indicated Air Speed (IAS)
    (read the IAS on the Primary Flight Display (PFD))
  • The altitude
  • The aircraft configuration (Landing Gear, Slat/Flaps position).
   (2) When the vibrations occur, observe and record:
  • Their intensity
  • Their direction
  • The area where they occur
  • If noise is related to the vibrations.
    These last two parameters give very important and necessary data for the identification of the vibration source. The flight crew must also do a check of the ECAM flight control page to find possible oscillations on the flight control surfaces.
    It is also possible to feel vibrations in the cabin. Thus, the flight crew must speak to the cabin crew to make sure their assessment is correct (aircraft area where the vibration is strongest for example) and for better reporting.
   (3) Parameter and flight condition changes (AP ON) that have an effect on the vibrations
NOTE: Vibrations can be caused by flight control surfaces. A parameter change with AP ON can supply information to identify the surface that is the source of vibrations.
During cruise, the flight crew can extend the speed brakes by a few degrees to monitor the vibration intensity variation.
When there is an acceleration, turn, climb or descent during the usual flight sequence (with AP ON), the flight crew must also monitor the effect on the vibrations and record all vibration intensity variations.
   (4) Parameter and flight condition change (AP OFF, FDs ON) that stops the vibrations
This section can be completed when:
  • The parameter and flight condition change (AP ON) did not stop the vibrations,
    or
  • Initial reporting did not make it possible to find the source of vibrations.
    When permitted by flight conditions and airline policy (*), the flight crew can disconnect the AutoPilot (AP) to try to identify the source of vibrations. The flight crew will then apply small and smooth flight control inputs to obey FD bar orders.
NOTE: Vibrations can be caused by flight control surfaces. The vibrations will possibly stop when the load on these surfaces increases.
This must be done in the sequence given on the VRS (pitch, yaw then roll):
  • Apply small and smooth inputs on the sidestick to obey the FD orders (pitch or roll).
  • If the vibrations do not stop, apply small rudder trim inputs of +/- 1.5° MAX (yaw).
  • Do not use the rudder pedals.
  • When the vibration reporting is completed, connect the AutoPilot again immediately (if the AutoPilot was ON before this procedure).
NOTE: (*)In RVSM airspace, the flight crew must keep the AP ON for altitude capture and level flight at the cleared FL.
Subtask 05-50-00-710-050-A
B. Find the Cause of the Vibrations and/or Noises
NOTE: If the vibrations occurred in this configuration:
  • Vibrations along the cabin and in the cockpit and
  • Elevator control with SECs in operation and ELACs not in operation,
no trouble shooting is necessary (elevator oscillations are wider in SEC mode than ELAC mode).
   (1) Use this procedure to find the cause of the vibrations.
F Process for the Identification of the Vibration Source
     (a) Vibration reporting sheet
F Vibration Reporting Sheet
If vibrations occur, the airline must record the related data on the vibration reporting sheet.
You must use this sheet to start all trouble shooting procedures related to vibrations.
NOTE: The more accurately the airline records the data on this sheet, the easier the trouble shooting will be.
     (b) Decision tree
F Decision Tree
Refer to the decision tree and the data on the vibration reporting sheet to find:
  • The source of the vibrations
  • The type of corrective actions that are necessary.
If you cannot find the cause of the vibrations with this tree, use the decision table.
     (c) Decision table
F Decision Table
The decision table is made to help the operator to find the possible causes of the vibrations.
Each line of the table is related to one of the parameters shown on the vibration reporting sheet.
If this parameter is applicable (there is data for it in the vibration reporting sheet), you must highlight all the figures on the line for the parameter.
When all the applicable lines are highlighted, add all the highlighted figures in each vertical column.
Record the total on the TOTAL line.
The highest totals show the most probable sources.
NOTE: Items with a value of less than 20 are not important.
     (d) Example of how to use the decision tree and the decision table.
F Example of How to Use the Decision Tree
F Example of How to Use the Decision Table
4. Fault Isolation
Subtask 05-50-00-810-050-D
A. Corrective Action Types
   (1) Type 1
     (a) The cause of the vibrations is incorrect rigging of the elevator and/or too much play at the elevator trailing edges:
NOTE: If the vibrations stop or start with airbrake inputs, Type 1 corrective action is necessary. This is because the airbrake movement can cause elevator vibrations.
   (2) Type 2
     (a) The cause of vibrations is elevator servocontrol oscillation:
   (3) Type 3
     (a) The cause of vibrations is too much play at the aileron trailing edges:
   (4) Type 4
     (a) The cause of vibrations is aileron servocontrol oscillation:
   (5) Type 5
     (a) The cause of vibrations is too much play at the rudder trailing edge:
   (6) Type 6
     (a) The cause of vibrations is the incorrect condition of the flap (1):
   (7) Type 7
     (a) Not applicable.
   (8) Type 8
     (a) The cause of vibrations is too much play in the NLG aft-door gimbal-joints:
   (9) Type 9
     (a) The cause of vibrations and/or noises is the seals of belly fairing panels 191AT, 192AT, 191BT and 192BT:
   (10) Type 10
     (a) The cause of vibrations and/or noises is the seals of belly fairing panels 191DT and 192DT:
   (11) Type 11
     (a) The cause of vibrations and/or noises is the seals of belly fairing panels 191ET and 192ET:
     (b) The cause of vibrations and/or noises is the seals of belly fairing panels 191LB and 192LB:
   (12) Type 12
     (a) The cause of vibrations and/or noises is the forward passenger/crew door:
   (13) Type 13
     (a) The cause of vibrations and/or noises is the aft passenger/crew door:
   (14) Type 14
     (a) Not applicable.
   (15) Type 15
     (a) The cause of vibrations is rudder servocontrol oscillation:
[Rev.8 from Aug 2018] 2026.04.04 04:38:49 UTC
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