In response to the original question about disposing toilet waste in flight, airliners do not dispose any toilet waste in flight.
Airliner toilets use a recirculating flushing system. The blue in the flush water is a very strong chemical that kills the bacteria and helps contain the odor. At the end of the day or the end of a long flight the holding tanks are drained and flushed and new blue flush water is added.
The toilets are serviced from the outside by lavatory servicing trucks, affectionately known in the airline industry as “honey bucket trucks” because toilets are called honey buckets.
A panel is opened under the airplane beneath the lavatory and a large hose is connected to a drainpipe. This drain has a hinged cap on it and after the cap is opened the hose is connected to the drain and then a shut off valve is opened and the waste drains into the truck. The valve is then closed and another smaller hose is connected to a separate fitting which pumps clean blue water into the holding tank. Sometimes this drain valve sticks open and when the drain line cap is opened, the operator takes a blue water shower. If the valve has a small leak, there will be some blue water in the drain line so the rule of thumb is check the wind direction and stand clear when opening the drain line cap.
This is why the toilets are placarded about not throwing anything down the toilet, it could damage the pump system or prevent the drain line from closing properly.
Blue ice forms when the shut off valve leaks and the blue water drips onto the hinged cap. If the cap seal is worn then the blue water drips out onto the access panel and then leaks out. As the airplane climbs, the outside air temp drops below freezing and the dripping blue water freezes on the outside of the airplane. As the airplane descends into warmer air, this frozen block of blue ice departs and becomes a small bomb.
At least one or twice a year, someone will report a block of ice hitting their house or car. Last year under the approach for JFK
, a block of blue ice hit a house and it went through the roof into the living room.
It appears that Ray Erickson saw the plane as the ice hit his boat or marked down the exact time it happened and it was traced back by radar images, so American Airlines was at fault. It probably was cheaper for AA
to pay the small claims than pay the lawyers to fight it if AA
felt it was not their fault. According to AA
’s web site flight 1950 is a LAX
to SFO MD
-80, departing at 5.20pm and arriving at 6.28pm.