weird 737 question

[chperplt]

Sitting toward the back of a 737 (any model) I hear what sounds like a washing machine in a continual rinse cycle.. What the heck is it???

 

[flint4xx]

Aft lav flushing.

 

[LearLove]

soda and water sloshing around???? I herd the water in the extra large bottles we have now slosh around quite a bit
comming from the aft galley but I'm not sure this is what your talking about.

Anyone have a good way of telling the diff. in 737 models outside of the 200's?

 

[80/20]

In the back…? .Could also be from a sliding carpet loading system in the aft cargo compartment, or water refilling. If it is a squeaky noise it could be an electric hydraulic pump. The standby hyd pump is especially noisy and will often cause questions about strange noise from crew and passengers seated in the back. The STBY HYD pump is not used during normal operations but might be part of certain ground checks..

 

[RUhiring?]

737-300 = one overwing exit
-400 = two overwing exits
-500 = not sure, haven't seen too many of these

-700 = one overwing exit and longer wingspan than -300. Plus on SW a/c the wing flap track fairings are orange.

-800 = two overwing exits and longer wingspan than -400

-900 = not sure on this one either, execpt that it's really long.

I know the -300 and -400 info is correct. Can anyone confirm and complete the rest?

 

[bigD]

You might be hearing the turbine and compressor of the ram air system (heat exchangers) or the turbofan by the ram air louvers. I'm not sure what else it would be.

I swear, FlyChicaga...you must know more random sh*t about transport category aircraft than any 300 hour pilot I know.

 

[sayagain?]

Can't miss ATA's 737-800s because of the winglets.

 

[80/20]

Chperplt I should have asked first - is your question during flight or on the ground?

(My suggestions above are for the ground before engine start.)

 

[chperplt]

The sound is while in flight. I can't think of any way to describe it other than a washing machine or dishwasher during a rinse cycle. I'll ask the crew when I'm on a 73 next...

 

[Deftone45075]

Is it only heard temporarily, or consistantly throughout the flight?

 

[WrightAvia]

Maybe they DO got one of them small apartment sized washer and dryer set ups in the back there...and some FA is riding on top of it with it's imbalanced load and it's a going "blub blub blub blub blub blub blub blub"?

 

[flint4xx]

Hello?????? IT IS THE AFT LAV FLUSHING.

 

[Av8trxx]

Inflight and it sounds like a washing machine? It's the recirculation fan reprocessing cabin air. There's one located under the rear floorboards of the aft cabin and they occassionally get squeaky. It's not always on though. There is an intake on the rear galley ceiling for it and the F/As hate it. Drawing in air it makes noise and drives the F/As crazy. They often put a paper towel or cups over it to block it and keep it quiet back there. Then when the F/O shuts the fan off they fall all over the floor. I think of that sound on my flight like a baby in a car seat.......I am always out like a light.

"a sliding carpet loading system in the aft cargo compartment"
If only we had those!

The lav motor makes a very different sound (esp on the -700) as does the STBY HYD pump. Plus the latter is a deep groaning sound and only lasts a few seconds during ground checks.

 

[350DRIVER]

Hello?????? IT IS THE AFT LAV FLUSHING.

That is the correct answer. Sometimes when the FA's discard their paper products (which they shouldn't) it throws the "cycle" off..

3 5 0

 

[shamrock]

Same plane, different question.

On the subject of the 737, has anybody ever noticed while taxiing behind one that they look like they taxi crooked? I never noticed until a crew I was jumpseating with pointed it out. Looks like the nose is pointed left even though the plane is taxiing straight. I would have thought it was maybe only one or two planes but most every one I've seen since then has looked the same.

Don't know if I'm seeing things or not but I was just wondering.

 

[Av8trxx]

Re: Same plane, different question.

On the subject of the 737, has anybody ever noticed while taxiing behind one that they look like they taxi crooked? .

There was a whole string devoted to this topic not too long ago. I can't find it though. Can somebody post the link????

 

[csmith]

Re: Same plane, different question.

On the subject of the 737, has anybody ever noticed while taxiing behind one that they look like they taxi crooked? I never noticed until a crew I was jumpseating with pointed it out. Looks like the nose is pointed left even though the plane is taxiing straight. I would have thought it was maybe only one or two planes but most every one I've seen since then has looked the same.

Don't know if I'm seeing things or not but I was just wondering.

You're not seeing things. If the gear is not perfectly straight down the runway at touchdown, the mains will caster and stay that way until the next liftoff--strut decompression. They caster as the airplane is certified to land in a crab. The xwind limit 31 kts, and the autoland in our airplanes is certified to 17 kts. The autopilot actually lands the airplane in a crab during an autoland.

 

[328dude]

Since we are talking about strange noises, anybody aware of what causes that weird grooning noise on the Airbus series (319,320,321,330) after they shut down in the gate? I was guessing some sort of hydraulic pump, but not real sure. It's not a constant noise but occurs about every 8 seconds or so. You will really hear it if you sit over the wings.

Just curious.

 

[bigD]

Since we are talking about strange noises, anybody aware of what causes that weird grooning noise on the Airbus series (319,320,321,330) after they shut down in the gate? I was guessing some sort of hydraulic pump, but not real sure. It's not a constant noise but occurs about every 8 seconds or so. You will really hear it if you sit over the wings.

Hydraulic pump for the baggage compartment hatch?

 

[TurboS7]

Who cares unless your an FA.