Toilet waste (Blue ice)

[Lan Ding Gere]

Correct me if I'm wrong, but is blue is the frozen water with a combination of the loo blo liquid, which you may get in some portaloos.

There have been some cases of this blue ice falling on peoples roof and cars. As it thaws out it turns out to be human waste. I can understand that at such a high altitude water freezes, but how does it manage to escape from within the plane, if the plane is sealed and not to let anything in or out ?

Just a curious question.

LDG

[wryly smiling]

usually a leaking dump valve and flapper valve on the dump line.
Leaks from outside the a/c at the service panel that the honey truck connects to when they dump the tanks after a flight

[lomapaseo]

People put strange objects down these loos and when they drain off the stuff at the gate using the honey truck and an entrance grade employee, the stuff gets stuck in the valve, then when he tries to close the valve he needs his hammer to make the handle and door appear flush again, which it doesn't. He then wipes away the dribble and walks away knowung that that the pilots walk-arround is going to steer far away from this door while carefully checking the potable water access door.

At altitude the differential in pressure causes the stuff to really start leaking, but yes it does freeze quite nicely only to shed when the palne descends towards landing.