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-   -   A320 Vibration (https://www.pprune.org/tech-log/428687-a320-vibration.html)

Machinbird 29th Sep 2010 02:04

From PJ2's referenced post of Aug 2009

I watched, as both horizontal stabilizers began fluttering up and down describing an arc of about 1 ft or so. They were fluttering at about 6 to 8Hz for about 20 seconds gradually damping then beginning again after about 40 seconds. The pattern did not vary with Mach or altitude. It would gradually stop after some time in cruise.
The danger of treating this type of problem as "Ops Normal" is that it is using up the fatigue life of an important part of the aircraft. If people are conditioned to routinely accept this type of vibration, then someday, somewhere, someone will have an exciting experience as the next level of failure makes itself known. :(

Took several months to fix.
Is not acceptable.

red 5 29th Sep 2010 08:57

Working for an Airline with nearly a 190 A319/320's A/F Vibration is a daily occurence, however once the Vib reporting sheets are accurately filled in and passed to Tech support they have a very neet programme that can identify the exact area. Yes most of it comes from replacing the Elevator & rudder eye ends and or Hinge bearings. Also the Ailerons can be of major concern, and once again PCA eye ends but more often than not the Aileron 'A' frame bearings are worn. Not the easiest job in the world as the Ailerons have to be removed, however it can all be done in a night shift if you know what you're doing.

chimbu warrior 5th Oct 2010 09:30

A little off-topic, but I was very surprised to see that this Airbus was scrapped after only 3 years.

Aircraft N808FR, 2007 Airbus A318-111 C/N 3038

Surely it had many more years of flying left in it?

aa73 5th Oct 2010 13:07

You forgot to retract the landing lights. I bet the vibration stops then. :ok:

PJ2 6th Oct 2010 15:16

aa73;

You forgot to retract the landing lights. I bet the vibration stops then.
:} Yeah, they do produce a lot of turbulence, (A319/A320/A321 series only - they're extendable to VMO if I recall) and resulting vibration but it is not at all the same as the airframe vibration I experienced.

As I described, there was a definite cycling, 6 - 8Hz, felt through the airplane and control pedestal, and I saw the horizontal stabilizers moving. red 5 describes the problem and solution very well.

Whether fatigue life is an issue or not is an engineering problem but instinctively I don't think anyone here believes that flutter is a good thing for an airframe.

This issue will undoubtedly be part of the AAIU investigation into the aileron-casting failure on an AerLingus A330.

PJ2

Cardinal 8th Oct 2010 22:27


A little off-topic, but I was very surprised to see that this Airbus was scrapped after only 3 years.

Aircraft N808FR, 2007 Airbus A318-111 C/N 3038

Surely it had many more years of flying left in it?
Our buddy Chloe most certainly wasn't scrapped for elevator vibration :) Frontier desired a lower cost per seat mile and she will be replaced with a new A320 in the spring. High CASM is giving the A318 poor resale value, but 90+% of parts are common to the family, so it made sense to scrap it.

tr1ggermckay 10th Oct 2010 10:24

It is indeed a very common problem. I can`t remember one day when the fault hasn`t been reported by at least one a319/20/21 into LHR. It is, as previously stated, nearly always the rudder eye-ends at fault.

gnd scan 26th Apr 2011 07:12

Automatic Vibration Printout
 
Does anyone know why the A320 sometime automatically prints an ENGINE VIBRATION SPECTRUM report.. about the lenght of your arm .. No Vibration experienced during flight ??


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