A320 Airframe Vibration

[Nightstop]

Any folks out there found the cause of the occasional airframe vibration which seems to mainly affect "older" MSN's of the A320 family? It seems to present as a rapid vertical vibration and can be stopped by small changes in pitch, roll or yaw with A/P disconnected. Not a safety issue, just an aerodynamic irritation imho, but I would be interested in opinions from the Pprune FBW fraternity.

[charlies angel]

1. Search 'A320 vibration' for days and days worth of threads on this subject
2. Just what is that strange "dog barking","sawing wood" noise on start up?
Happy New Year one and all

[ampclamp]

Most likely its the hyd PTU running.It is a shocker.

[Machinbird]

Nightstop, you appear to be describing limit cycle oscillation of the elevator. Take a look at this old thread on the subject. http://www.pprune.org/tech-log/38521...vibration.html

[TO MEMO]

Machinbird is correct!
It is a well known issue with the A320.
Check this one:http://www.airbus.com/store/mm_repos...A320_ATA27.pdf

Cheers!

[ChristiaanJ]

I'm very much NOT a member of the A vs B brigade, but when flying as an SLF, I always found the A320 to be much like a flying and rattling Coke can, noise and vibration-wise, much unlike the 737.

CJ

[DozyWannabe]

Whereas I've had many wonderfully smooth rides, and one or two hair-raisers, on both!

[Slasher]

An engineer accidently left a scrunched up piece of speed-tape on
top of one of the stabs once. Made a hell of a bloody vibration of
medium amp and wasn't till we got on the ground we could find
out what was going on.

Said engineer got yelled at on return to base.

[dream747]

I noticed that on the A320s there are a lot of airframe vibrations and shudders from the start of rotation to the climb attitude on takeoff. It can only be felt at the front to the mid cabin area. Is this simply the result of "introducing" the airframe to the airflow or are there any other factors? I'm not sure if this is common on other aircraft types; I've only had the chance to be in the front on the A320s.

[FlightDetent]

Quite possibly nose wheel induced. When the tires (or slush contaminant on them) are not in perfect balance, the vibrations often run strong until NW is retracted and fully braked within the well.

Sincerely,
FD (the un-real)