Strange flying experience...

[Omag 2.0]

Hi all, it's been a long time, but after a flight from Rhodes Airport (Greece) to Brussels, I have a question.

First, let me state that I'm always anxious about flying. I love watching airplanes, but when I have to fly... urgh... I know, it's stupid. But it causes me to pay attention to things other people might not even notice.

Today the flight was performed by an Airbus A320 (Thomas Cook airlines)

As we boarded the plane ( using a stair - Rhodes is a small airport), I noticed the left engine spoiling slowly, while producing a high whining sound. But I also heared an obvious rattle sound. Almost like a kid putting a playing card against the spokes of his bike, but metallic in sound. I kinda freaked me and I saw another guy looking at the engine with a weird eye too. But as there were flight personel walking around, I didn't say anything and just boarded.

The plane left, without any problems. But during the entire flight I could feel an oscilating vibration, coming from the left as it felt. The only time it stopped, was when the engines went to almost idle on the descent.

Now, I really don't think there was any real danger, but I'm wondering what I might have heared. I'm looking for a possible logic explanation for all of this, especially as I have to fly again in two weeks... 

Anyone an idea?

Thanks.

Omag

[SaultFresh]

May have heard a disgruntled wizard operating the engine. With that being said, I have no idea what you heard :-/
My hypothesis is that, maybe something was stuck to one or more of the impellers, causing an imbalance, and therefore vibration. What would get stuck to an impeller without damaging it, I don't know, but that's my somewhat kind of educated guess.

[DaveSims]

Take it easy, as I can explain this one fairly easily.  On turbofan engines, the fan blades are actually loosely mounted, in other words they have some slack in them.  When parked, the wind might blow enough to turn the blades, and as the spin slowly they will make a clinking sound as they move a little.  This is completely normal, and nothing to worry about.  The high pitch sound you heard was probably coming from the APU, mounted in the tail of the aircraft.  As for the vibration, its an Airbus.   ;D

[expat]

[quote]Hi all, it's been a long time, but after a flight from Rhodes Airport (Greece) to Brussels, I have a question.

First, let me state that I'm always anxious about flying. I love watching airplanes, but when I have to fly... urgh... I know, it's stupid. But it causes me to pay attention to things other people might not even notice.

Today the flight was performed by an Airbus A320 (Thomas Cook airlines)

As we boarded the plane ( using a stair - Rhodes is a small airport), I noticed the left engine spoiling slowly, while producing a high whining sound. But I also heared an obvious rattle sound. Almost like a kid putting a playing card against the spokes of his bike, but metallic in sound. I kinda freaked me and I saw another guy looking at the engine with a weird eye too. But as there were flight personel walking around, I didn't say anything and just boarded.

The plane left, without any problems. But during the entire flight I could feel an oscilating vibration, coming from the left as it felt. The only time it stopped, was when the engines went to almost idle on the descent.

Now, I really don't think there was any real danger, but I'm wondering what I might have heared. I'm looking for a possible logic explanation for all of this, especially as I have to fly again in two weeks...

[Splinter562]

But I also heared an obvious rattle sound. Almost like a kid putting a playing card against the spokes of his bike, but metallic in sound. I kinda freaked me and I saw another guy looking at the engine with a weird eye too. But as there were flight personel walking around, I didn't say anything and just boarded.

On the A320, this sound (also described as a "barking dog") comes from something called the Power Transfer Unit (PTU). It allows the hydraulic system on one engine to pressurize the system on the other without transferring (or potentially contaminating) hydraulic fluid between the systems. You hear this noise when only one engine is running (like pushback or when taxing on one engine).

http://en.wikipedia.org/wiki/Power_Transfer_Unit

[Omag 2.0]

Thanks all.

Davysims and Expat, you guys are the reason why I posted this question here. I knew there was a logical explanation for what I heared. I just needed to know from a reliable source. :-)

I hardly can imagine that so much personel around the plane wouldn't have noticed it anything was really wrong.


And yes, it's been a long time. Maybe I should visit some more again.

Cheers!

Kris

[expat]

But I also heared an obvious rattle sound. Almost like a kid putting a playing card against the spokes of his bike, but metallic in sound. I kinda freaked me and I saw another guy looking at the engine with a weird eye too. But as there were flight personel walking around, I didn't say anything and just boarded.

You hear this noise when only one engine is running (like pushback or when taxing on one engine).

On the A320 the PTU is operating when ever the hydraulics are pressurised, be that by engine or by electric motor.

Matt

[BrandonF]

[quote]As for the vibration, its an Airbus.

[Omag 2.0]

Reasuring theory... lol.