Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
What Happened On This 752? (Lav Related)  
User currently onlineKELPkid From United States of America, joined Nov 2005, 6390 posts, RR: 3
Posted (7 years 1 month 4 weeks 13 hours ago) and read 3434 times:

Hi,

Well, I flew out to the East Coast last Saturday on a P&W powered 752, and the leg that this happened on was SLC-BWI (I'm sure you guys can put 2+2 together and guess the airline  Wink ). Well, on this particular leg, I got up to use the forward lav, and the first thing I noticed was that the flapper in the crapper was hanging ajar. Well, I did my business, and flushed (maybe I really didn't need to, since the flapper didn't shut and it all went down anyways), and the blue lav juice just kept flowing and flowing and flowing for what seemed like an eternity instead of the usual short burst you get in an airline lav.

At this point, we were about 1 hour into our 4 hour flight....

Then (~30 minutes later), my mother in law (who's flying in my party) goes to one of the aft lavs, and comes back about 10 minutes later. She says she had to summon a flight attendant after the toilet won't flush... shortly after she takes her seat, we hear "Ding! Ladies and gentlemen, we are currently experiencing a malfunction of the lavoratory system and ask that you not use the lavatories for the remainder of the flight..."  Wow!  Yeah sure  Angry

Anyone know what happened here?

P.S. My internet access is currently sporadic, as I am on the road for the next week.


Celebrating the birth of KELPkidJR on August 5, 2009 :-)
12 replies: All unread, jump to last
 
User currently offlineDl757md From United States of America, joined May 2004, 1562 posts, RR: 16
Reply 1, posted (7 years 1 month 4 weeks 9 hours ago) and read 3366 times:

Can't tell you what happened because I don't know the details of what happened but I can tell you that our 752s have 4 lavs and they are all independent of each other. You indicate problems with two of them, although the first doesn't sound like a problem that would cause it to be locked out. It did stop flushing, right? It would be unlikely, not impossible, but unlikely that all 4 lavs would malfunction during the same flight. As I said they are all self contained units independent of each other. Anyway, without more details I can't tell you much more that wouldn't be pure speculation. Sorry about the inconveniance.

DL757Md



757 Most beautiful airliner in the sky!
User currently offlineBuzz From United States of America, joined Nov 1999, 697 posts, RR: 21
Reply 2, posted (7 years 1 month 4 weeks 3 hours ago) and read 3313 times:

Hi KELP kid, Buzz here. We've also got 757's in our fleet... and like the Delta guy I could only make an educated guess.
That blue juice pump runs on a timer... sounds like it's time to change it. I'm trying to think if there's a common power circuit breaker to all 4 lavs... I'm thinking they're isolated. Just a run of bad luck on that airplane I guess.

Most of the time our problem is that people drop "foreign items" into the pooper, holds up the dump valve so the blue juice drains away into the big dump pipe... no flush. Good thing I don't have much sense of smell when I fix things like this.

My wife and I are going to the Steam Up down by Salem OR. I doubt I'll find any steam powered airplanes (grin) But I'll be looking at the sky anytime somebody flies by.

g'day


User currently offlineMD11Engineer From Germany, joined Oct 2003, 14027 posts, RR: 62
Reply 3, posted (7 years 1 month 3 weeks 6 days 8 hours ago) and read 3149 times:

Quoting Buzz (Reply 2):
My wife and I are going to the Steam Up down by Salem OR. I doubt I'll find any steam powered airplanes (grin) But I'll be looking at the sky anytime somebody flies by.

The C-54 I worked on had the old "bucket in a box" crapper. How about your DC-3s?  Silly

Jan


User currently offlineHAWK21M From India, joined Jan 2001, 31684 posts, RR: 56
Reply 4, posted (7 years 1 month 3 weeks 5 days 7 hours ago) and read 2999 times:

Quoting KELPkid (Thread starter):
since the flapper didn't shut and it all went down anyways), and the blue lav juice just kept flowing and flowing and flowing for what seemed like an eternity instead of the usual short burst you get in an airline lav.

The Liquid system is a recirculatory one with the Fluid reused from Tank to Motor filter assy to Commode to Tank.The Flapper in the commode shuts with spring tension.
If the Timer did not autoshut off.The CB would trip or motor burn out.Unless the Dump valve is leaking or stuck open.You wont loose the Blue Juice.

Quoting KELPkid (Thread starter):
had to summon a flight attendant after the toilet won't flush

Was that to suggest the Flush motor was functioning but no blue juice or The flush motor was u/s.

regds
MEL



Think of the brighter side!
User currently offlineFlyingColours From United Kingdom, joined Dec 2003, 2315 posts, RR: 10
Reply 5, posted (7 years 1 month 3 weeks 4 days 20 hours ago) and read 2886 times:

There was a very good thread started last year, and the subject was, you guessed it - aircraft lavs. Although it ran for 68 posts there is a lot of great info in there, specifically a few bits on the 757 (inc a bit from myself - as a flight attendant).

http://www.airliners.net/discussions...id=168886&s=FlyingColours#ID168886

Quoting HAWK21M (Reply 4):
The Liquid system is a recirculatory one with the Fluid reused from Tank to Motor filter assy to Commode to Tank.The Flapper in the commode shuts with spring tension.
If the Timer did not autoshut off.The CB would trip or motor burn out.Unless the Dump valve is leaking or stuck open.You wont loose the Blue Juice.

In all fairness, those flaps are usually quite worn out and don't close properly. I know if the toilet motor was still running after 20 seconds we would manually turn the motor off and pull the CB. When I was back at Excel & Islandsflug we were supposed to check the lavs every 20 minutes and one of these checks was to see if the motor stops after 10 seconds.
As for the blue juice, if we flushed and nothing came out we would just pour 2 pots of water in there, of course if the dump valve is open then that water will be lost.

As was mentioned in the thread I linked to, it says that on the 757 the "Recycle" type of Lavs have independent tanks, I know the pneumatic ones are all linked, so if one breaks they all do...

Phil
FlyingColours



Lifes a train racing towards you, now you can either run away or grab a chair & a beer and watch it come - Phil
User currently offlineDl757md From United States of America, joined May 2004, 1562 posts, RR: 16
Reply 6, posted (7 years 1 month 3 weeks 4 days 15 hours ago) and read 2781 times:

Quoting FlyingColours (Reply 5):
I know the pneumatic ones are all linked, so if one breaks they all do...

Not necessarily. Generally in a vacuum waste system each toilet has a flush switch, flush control unit, flush valve, and a rinse valve. The failure of any of those components would INOP only the specific lav that it was located at. Additionally, waste line blockages can affect one or more toilets but rarely all of them as there is more than one waste line inlet to the waste tank so you would need to have multiple blockages to INOP all the lavs.

DL757Md



757 Most beautiful airliner in the sky!
User currently offlineTristarsteve From Sweden, joined Nov 2005, 4010 posts, RR: 33
Reply 7, posted (7 years 1 month 3 weeks 3 days 17 hours ago) and read 2640 times:

Quoting Dl757md (Reply 6):
The failure of any of those components would INOP only the specific lav that it was located at.

One thing we must remember is that 90pc of toilet failures are because the tank is full. On a recycling toilet (where you see blue water when it flushes) this is pretty obvious. On a vacuum toilet there is a level switch at the top of the tank. When the tank is full this just shuts down the system. On a large aircraft, like the B777 there are 3 waste tanks, and one tank filling up will only shut down the toilets connected to it. But a small aircraft like an A320 only has one tank. When it's full all the toilet flushes are disabled.
The biggest defect on toilet systems is that they were not serviced before departure. On short sectors this is OK as an A320 toilet tank will last about 3 2hr sectors, but on a B777 then the tanks will fill up mid flight and thats it.
But both aircraft have a display that shows how full the tanks are. All that is needed is for the cabin crew to refuse to depart if they are not serviced. Fat chance.


User currently offlineDl757md From United States of America, joined May 2004, 1562 posts, RR: 16
Reply 8, posted (7 years 1 month 3 weeks 3 days 16 hours ago) and read 2626 times:

Quoting Tristarsteve (Reply 7):
One thing we must remember is that 90pc of toilet failures are because the tank is full.

Not where I work. Toilets are serviced at least every other flight. I have in 8 years of line mtc seen only a handful of lavs that came in locked out because of full tanks and they are invariably because of ground delays or diversions. Compare that to during the same time I have removed obstructions from the dump valve of 757 lav tanks 116 times. At Delta it's just not much of an issue let alone THE MAIN issue. I've also been on over 800 flights on Delta and have yet to encounter a lav locked out due to being full on any of these flights. Why do we have such wildly different experiences on the same subject?

Quoting Tristarsteve (Reply 7):
The biggest defect on toilet systems is that they were not serviced before departure.

I guess Delta just has an effective servicing policy that prevents full lav tanks.

DL757Md



757 Most beautiful airliner in the sky!
User currently offlineBAe146QT From United Kingdom, joined Sep 2006, 996 posts, RR: 0
Reply 9, posted (7 years 1 month 3 weeks 3 days 14 hours ago) and read 2598 times:

Quoting Dl757md (Reply 8):
I guess Delta just has an effective servicing policy that prevents full lav tanks.

I reckon that's because of all the fried chicken, gravy and grits. Last thing you want on your plane departing ATL is 200 rednecks like me holding back a gutful of southern food. It'd be carnage by the time you got to Chatanooga.



Todos mis dominós son totalmente pegajosos
User currently offlineFlyingColours From United Kingdom, joined Dec 2003, 2315 posts, RR: 10
Reply 10, posted (7 years 1 month 3 weeks 3 days 3 hours ago) and read 2527 times:

Quoting Tristarsteve (Reply 7):
But both aircraft have a display that shows how full the tanks are. All that is needed is for the cabin crew to refuse to depart if they are not serviced. Fat chance.

Yeah the 737NG has a panel in the cabin so we can check the tanks, also shows the amount of portable water onboard - best not get the two mixed up....

Quoting Tristarsteve (Reply 7):
On a recycling toilet (where you see blue water when it flushes) this is pretty obvious

You would think that wouldn't you? One day we departed back to Manchester from SKG and only realised shortly after takeoff that 3 of the 4 lavs were almost completley full (specifically 2 which were adjacent to my crew station). It turns out that in SKG you have to request a service, usually everywhere else does it straight away and you only ask them if you don't want a service (ala light loads on the inbound)).

Quoting BAe146QT (Reply 9):
I reckon that's because of all the fried chicken, gravy and grits. Last thing you want on your plane departing ATL is 200 rednecks like me holding back a gutful of southern food. It'd be carnage by the time you got to Chatanooga.

Hahaha, you ever seen 233 holidaymakers kick off because you told them there is only 1 toilet avaliable?....

Phil
FlyingColours



Lifes a train racing towards you, now you can either run away or grab a chair & a beer and watch it come - Phil
User currently offlineHAWK21M From India, joined Jan 2001, 31684 posts, RR: 56
Reply 11, posted (7 years 1 month 3 weeks 3 days ago) and read 2498 times:

Quoting Tristarsteve (Reply 7):
The biggest defect on toilet systems is that they were not serviced before departure.

Refilling to a certain level providing adequate space helps.
regds
MEL



Think of the brighter side!
User currently offlineTristarSteve From Sweden, joined Nov 2005, 4010 posts, RR: 33
Reply 12, posted (7 years 1 month 3 weeks 2 days 23 hours ago) and read 2486 times:

Quoting Dl757md (Reply 8):
Compare that to during the same time I have removed obstructions from the dump valve of 757 lav tanks 116 times. At Delta it's just not much of an issue let alone THE MAIN issue

On our European network we service lavs at main base, and on nightstops. This is sufficient. But the problem is that when the lav man does not service the lavs, no one seems to notice. I have been trying to educate cabin crew for years, but they still manage not to react when they leave main base with the indicator showing 75pc full.

The issue of blocked dumpvalves has been greatly reduced lately. We have removed items from the lavs that block the dump valves. We have no small bottles of perfume, no bars of soap, water degradable tissues, no cotton hand towels. Since all this was introduced a couple of years ago, blocked open dump valves seem to be a thing of the past.


Top Of Page
Forum Index

Reply To This Topic What Happened On This 752? (Lav Related)
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
What Exactly Is This On The Front Of The A/C? posted Sat Jan 20 2007 12:06:16 by RootsAir
What Is Wrong On This Finnair A340? posted Tue Jul 18 2006 21:36:41 by Lufthansi
What Is The Errant Wire On This CO 757? Photo posted Tue Jun 7 2005 04:14:34 by FlyingTexan
What's On This Wing? posted Tue Jul 20 2004 23:02:51 by Ualisthebst
What Are The Experts Opinions On This Stuff? posted Wed Mar 26 2003 22:31:46 by C172Akula
DL 727 Boom! Boom! Boom! What Happened? posted Wed Jun 13 2007 00:35:09 by UAL747
The Ultimite What Plane Is This Quiz posted Sat May 19 2007 22:17:19 by Airfoilsguy
What Airplane Is This? posted Fri Mar 9 2007 21:26:24 by A346Dude
Question On Quads...(engine Out Related) posted Thu Jan 11 2007 00:30:10 by KELPkid
What Aircraft Is This? posted Wed Jan 10 2007 17:17:56 by AirKas1

Sponsor Message:
Printer friendly format