Moderate Vibrations: Cabin Floor in A332

[condorbaaz]

A friend of mine recently told me about Severe Vibrations reported by Aft Galley, (the containers were moving within the latches hard), making it impossible for the crew to work.

The FO also saw first hand the vibes.

Captain Decided that it was due to "Cabin Recirc Fans" and put them off for an hour.

Vibrations reduced, and did not recur when fans were put on.

Me thinks it could have been flutter due to high speed as well..

Advise guys..

[lomapaseo]

what frequency?

were the seatbacks or overheads moving?

Was the inside of the aft lav trashed?

were the passengers in the back sound asleep with the hum?

if not .... no worries

[CEJM]

Airbus have got a Vibration Reporting sheet which the pilots fill in when we feel vibration. It has the pilots look at several indications and report it back to engineering which assists them in trouble shooting.

In our company one of these sheets is in the front of the tech log so that it is always at hand.

And you mention that you expect high speed to be the culprit. Do you know which speed they were flying at? The A332 vibrates a little bit at Mach 0.84 or higher.

[TO MEMO]

Not on an A330, but on an A320.
Where I work, an A320 experienced strong vibrations in the MID cabin.
All normal, flight proceeded to destination.

What was it?
RAT self deployed inflight!

Interesting...

[dhardesthard]

RAT self deployed in flight.

Is there a speed limit with the RAT deployed in this case?

[condorbaaz]

speed .82 to .83 m

pax disturbed

galley containers jumping in latches

thanks

[Machinbird]

The A320 has had problems in the past with Limit Cycle Oscillation of control surfaces. Perhaps the A330 does too.

Essentially slop can build up in actuator attachments due to wear and a control surface can limit cycle oscillate over a small extent extent due to accumulated slop.

If attaching points are still in wear limits, maintenance can then rig in some aerodynamic bias which will hold the surface hard against the actuator.

An inspection of all control surfaces that are visually accessible inflight might be enlightening, but careful execution of the vibration event form is essential.

It would be helpful to hear from an Airbus maintenance specialist regarding that part of the problem solution.

[lomapaseo]

speed .82 to .83 m

pax disturbed

galley containers jumping in latches

thanks

OK, sounds like very low frequency. Unlikley to be structure generated. The kind of stuff like running over rocks with a 4-wheeler.

I'll let the aero guys sort this out

For Pax disturbed, just open up the free booze cart