Spoons and socks may not be the first objects that spring to mind when gazing at the world's largest airliner, but deep inside an Airbus factory, technicians kill time by stuffing them down the toilet.
Flushing away strange objects is among the unglamorous tasks carried out on a giant three-story rig designed to test the vacuum-toilet system on an A380 superjumbo.
While the plane's electrical wiring problems occupy the attention of would-be buyers and the world's media, plumbers are perfecting the A380's 3,000-plus feet of waste and water pipes.
Airlines know from experience that many passengers are careless about what they drop down the lavatory — and blockages on a $300 million airliner could spell a public relations disaster.
"The toilets are very important to airlines. Some people put anything down there: towels, spoons, glasses, diapers. They behave as if they were at home," said Frank Dohrmann, head of design support and cabin testing at Airbus's main German plant.
"If the temperature inside an aircraft varies 0.5 degrees it is no big deal. But if the toilets get jammed every passenger will remember it for years," he said.
One airline insisted that Airbus test the toilet by shoving pairs of socks down the system to check it wouldn't block.
To handle the waste produced by up to 800 passengers, Airbus designed plumbing capable of pumping sewage along the 200-foot length of an A380 in about two seconds, Dohrmann said.
That equates to more than 60 mph, which could be a sanitary speed record.
With airlines up in arms over the wiring problems that delayed A380 deliveries for months, Airbus cannot afford to make mistakes on the sensitive matter of waste treatment after experiencing toilet problems with an earlier model.
To put the A380's 18 toilets and other water systems through their paces, the 200-tonne test rig can be titled upwards and downwards to simulate severe flying conditions.
The A380 plumbing includes capacity for showers, a feature demanded by several airplanes. But to the jetset's disappointment, it is unlikely to include a Jacuzzi.
Despite media speculation of whirlpools alongside casinos, bars and shops, the use of uncontrolled water is discouraged and would probably not be approved by flying authorities, said Michael Lau, head of industrial design.