Anyway – back to our story.
That’s when I learned how the flushing system on the Airbus A320 works. Of course, a computer is involved. At lower altitudes flushing is a function of some sort of electro-mechanical, vacuum-producing pumps, but as we climb higher another system takes over that uses differential pressure between the inside and the outside of the aircraft to suck and swirl away the offending contents of the toilet bowls and deposit this into the holding tanks. The key change-over altitude is 16,000 feet.
So, after resetting some obscure on-board computer, and checking over and over again that all three of the toilets flushed properly on the ground — something I personally tested, knowing my own bladder range limitations — we pushed back from the gate and departed. However, we knew that the moment of truth lay ahead — or above — that is. Only after we’d climbed through 16,000 feet, where the system switches over to the secondary mode of operation, could we be sure that our toilets would keep flushing for the duration of the trip to Montreal. With a full load of passengers plus crew-members, this was not a trivial matter — although it was hard not to make light-hearted jokes about it.
“BZZZZZZ!” The flight attendant call-tone blasted loudly in the flight deck, once again providing an unintended test of my cardiac fitness. Every time this annoying horn went off (which was frequently in any given day’s work) I mildly cursed the Airbus engineers or regulatory authorities who I blamed for setting the volume of this darn thing. It’s literally the loudest warning on our Airbus flight decks.
I fumbled for my handset to make the noise stop. “What’s the news?”
“Not good, Captain. None of the toilets are flushing.”
“Okay.” I felt my own bladder twinge at the thought of the several hours to go before we would arrive in Montreal. “Any ideas?” I asked.
“Can we make an en-route landing and ask people to hold themselves as much as possible? If anyone has an emergency, the toilet bowls will handle that much — I hope.“
“I can’t think of anything better,” I said. “Do you want to tell the passengers or will I?”
“You’d better say something,” he replied. “They probably won’t believe me.”
“Okay. Just give me a minute to coordinate with company and make sure this fits into their “Big Picture.” Maybe we’ll get lucky and they’ll find us an aircraft swap. Winnipeg Is about half way. It’ll be our best bet.”
I took a moment to brief the first officer who was capably flying this leg and, so far, seemed not to have gotten us lost. Then, after assuring myself that he was also handling our ATC communications, I connected with our company dispatcher on number two radio. It took a few minutes to get the urgency of our problem accurately understood. “No! We can’t just use the sick sacs!”
After that, we coordinated a plan to make the pit stop at Winnipeg. It was doubtful that they’d have a spare Airbus sitting around to exchange with our broken machine, but they did have working toilets in the terminal building. And, importantly, they had a full maintenance facility available so maybe, just maybe, they could take one more crack at solving the flushing problem and make “it” all go away. Literally. We hoped.
Finally, I picked up the PA handset from it’s holder on the center console, and pushed the necessary buttons, and prepared to make one of the strangest announcements ever to my passengers.
“Attention, this is the captain. Please hold your pee.”
Well, not quite like that — but sort of.
…To be continued… (cross your legs as required)