A/c train From United Kingdom, joined Jun 2001, 501 posts, RR: 4 Posted (12 years 8 months 2 days 11 hours ago) and read 1705 times:
What is this blue ice I keep on hearing about, it went through a roof on the approach to Luton I heard, were is it leaking from? it must be a valve leaking or something , can someone tell me were and what the blue ice is and what system it goes into, my GUESS!!! is water tank but not sure,
Mr Spaceman From Canada, joined Mar 2001, 2786 posts, RR: 9 Reply 1, posted (12 years 8 months 2 days 10 hours ago) and read 1620 times:
Hi A/c train. The first thing that comes to my mind is the lavatory. The "Dis-infectant Chemical" that is added to the water supply for the toilets is "Blue", and smells like bubble gum. If an airliner is leaking water from the Lav or even "dumpping" the Lav, I'm sure the water would freeze at altitude, and be a blue colour. Thus..."Blue Ice"
Mr Spaceman From Canada, joined Mar 2001, 2786 posts, RR: 9 Reply 2, posted (12 years 8 months 2 days 10 hours ago) and read 1608 times:
I have read that if the "Tail Skid" fails to retract on a B-727 after takeoff, then the pilots have to shut down the AFT Lav and close the valves which alow water to exit the tail in front of the skid. If this isn't done, then water exiting from the Rear Lavs will form a nice chunk of "Ice" around the tail skid. Once the 727 decends into warmer air while on approach, the chunk of ice simply melts off and falls away to who knows where? Maybe your roof!
242 From United States of America, joined Oct 2000, 498 posts, RR: 1 Reply 3, posted (12 years 8 months 2 days 10 hours ago) and read 1612 times:
It's blue water leaking out of the dump chute of the waste tanks.
Most tanks have a valve at the top of the chute, a seal at the bottom known as the lav donut, and a cap at the end. In normal servicing, the lav driver opens the cap, attaches the hose from his truck. The hose has provisions to remove and install the donut while it's connected to the aircraft. Once this is done, there's a pull handle that opens the dump valve at the top of the chute that allows the contents of the tank to gravity drain in to the truck.
If any of these components fail, it could cause a leak, but what normally happens is that the driver forgets to re-install the donut, meaning that the dump valve and the cap are the only sealing elements. If the dump valve sticks open for some reason, the cap at has the entire job of keeping the fluid in the tank. This also results in a nasty surprise for the next lav driver. The next time you hear someone say that there is a whole school of "brown trout" under the aircraft, you'll know what they mean.
Worst case scenario is a leak that results in a large chunk of ice that breaks loose when its mass gets large enough and causes damage to the aircraft or things on the ground below it.
F-WWAI From Andorra, joined Dec 1999, 131 posts, RR: 0 Reply 4, posted (12 years 8 months 2 days 10 hours ago) and read 1599 times:
there's stories around on good old 727 losing blue ice slumps because old toilet systems leak overbord in flight. that comes off during descent / landing and can eventually go into an engine .. this blue ice stinks.
don't know whether all that's true.
you might also have "blue ice" in special, rare icing condition. It's ice building up quite fast on non- de-iced supercold surfaces and reach thick layers. This also comes off in descent. It looks transparent blue ... and does not smell at all.
Mr Spaceman From Canada, joined Mar 2001, 2786 posts, RR: 9 Reply 5, posted (12 years 8 months 2 days 10 hours ago) and read 1592 times:
Ha Ha! 242. Been there-done that! I know all about that special "Surprise!!!" your talking about. Years ago when I worked on a ramp with DASH-8's, many times, who ever's turn it was to "Dump the Lav" didn't know that the valve "PUCK" was not in place untill it was to late. Nothing like a soaking wet uniform!
What you called the Donut, we called the Puck [what do you expect from a bunch of Canadians Eh!]
However, sometimes we were lucky. If the Puck was accidently stuck in the "Honey Bucket" back at the point of departure, and the main Cap was leaking the Lav fluid really bad, you were WARNED by the "Blue Streak" that was smeared the whole length of the aircraft, from behind and under the Co-Pilot's window, all the way back to the tail! What a site, but a good Warning!!
Yaki1 From , joined Dec 1969, posts, RR: Reply 7, posted (12 years 8 months 2 days 8 hours ago) and read 1586 times:
Blue ice is from defective lavatory holding tank seals. The blue color is the deodorizer added to the water when the tank is serviced. Common causes are defective fill/flush line check valves and leaking dump valves. Although secondary protection such as the donut, as metioned above,(sometimes a dual sealing dump line cap) or fill line cap should prevent leakage. A common maintenance check is to fill the lav tank above the toilet bowl level, pressurize the aircraft and watch for leaks at the service panel. A vacuum tank is also available that fits agaist the fuselage and has a viewing glass. Blue ice is a serious and potentially dangerous problem. Large chunks of ice have gone through the roofs of homes, or caused major engine damage.
Tuffty From United Kingdom, joined Mar 2001, 92 posts, RR: 0 Reply 8, posted (12 years 8 months 2 days 6 hours ago) and read 1560 times:
blue ice comes from the bogs, it is leaking usually from the release valve(as they never seem to close properly from my experience). It is a mixture of the toilet chemical and the contents of the waste tank. As it leaks at altitude it freezes in the extreme cold and as it thaws, usually on aproach it falls off, so if you see it dont touch it!!
OPNLguy From , joined Dec 1969, posts, RR: Reply 9, posted (12 years 8 months 2 days 5 hours ago) and read 1563 times:
Blue ice on the 727 forward lav access panel has led to at least two (that I know of) in-flight separations of the number 3 engine. The lav ice being ingested into the engine stopped its rotation so suddenly that the engine essentially torqued itself right of the airframe...
The first incident I can recall was a National 727 enroute from IAH (or MSY) to the west coast, back in the 1970s. The other was back in 1985, and involved an AA flight DFW-SAN. Ironically, both separations took place over the state of New Mexico. (Let the Roswell/UFO conspiracists begin).
The National 727 report is too old for the NTSB's online database, but here's something on the more recent American flight.
Here in the US (after the AA incident) FAA put out various airworthiness directives (ADs) that directed attention at the lav dump valves on 727 and other aircraft. Not to say there has never been another lav leak since, but you sure don't seem to hear about it here like you used too..
737LAME From Norway, joined Apr 2001, 75 posts, RR: 4 Reply 12, posted (12 years 8 months 1 day 11 hours ago) and read 1517 times:
The chemical is called "Raccasan".
I have seen pretty big dents in the Horizontal stabilizer LE (and this happens to the Right side! :-( )
The #2 engine have also got damaged fan blades due to blue ice from the fwd toilet servicing panel.
Most of the causes for blue ice as I know of is that the one that services the toilet, removes the rubber seat on the flush connection, and when the a/c gets airborne, there can be a backflow from this line. Creates a blue ice from 0.5 kg to 2.5 kg.
If the upper drainvalve should fail to seat due to hairbrushes, soap canisters, vibrators or other belongings to pax (belive me I have removed them )
There has also been installed a ball valve in the drain line inside of the servicing point on a/c with fwd toilets. That will help on this problem.
Dc10hound From United States of America, joined Dec 2000, 463 posts, RR: 6 Reply 14, posted (12 years 8 months 1 day ago) and read 1487 times:
Yeah, and the AAL B727 dropped it's #3 motor into a Indian reservation in New Mexico. So they found it in "Engine" country. My apologies for not being Politically Correct. (The Mescalero Apache made jewelery out of it, set it up by the side of highway US54 , and sold it piece by piece). )
"Eagles soar. But weasels never get sucked into jet intakes.."