It takes up to 500 working hours to clean the outer shell of a jumbo jet from top to bottom. This means that even a 15- to 20-man aircraft cleaning team has to spend 25 hours scrubbing, cleaning, and polishing before the aircraft can finally take off again.
Fortunately, the outer shell of an aircraft doesn’t need to be cleaned after every flight like the inside, just twice a year. This is, of course, a good thing for airlines because they are unable to earn money while the aircraft is grounded.
Environmental friendliness pays off
Clean aircraft do not just function as ambassadors for an airline. If they are clean, the machines are also more aerodynamic (lower resistance to the wind). This means they use less fuel and are therefore more environmentally friendly.
Aircraft used to be washed with lots of foam and huge amounts of water. Around 10,000 liters were required for a Boeing 747-400, and this water had to be extensively filtered before it could be fed back into the sewage system. And although wet washes like this were completed comparatively quickly in just eight hours, they needed to be carried out every three months. This is why most large aircraft are now dry-cleaned with specially developed cleaning materials. This takes longer, but only has to be done half as often and saves time and money as well as water, as other maintenance and interior cleaning work can be done at the same time.
Around 120 employees at Frankfurt Airport are responsible for restoring the planes to their glossy state. They work in shifts around the clock and manage to clean an average of eight aircraft a week.
All sensitive sensors and instruments, such as the speedometer, temperature gauge, and altimeter, are carefully peeled off in the hangar (aircraft hall) first. The tires are also wrapped to protect the brakes from chemicals. The outer shell of the aircraft is then rubbed with new kinds of cleaning materials by hand, which are wiped off later using reusable mops to remove dirt and smooth and seal the surface.
Given that so much effort is involved, people have thought about developing high-tech machines to make the work easier and faster, but all previous attempts at this have failed because even cutting-edge robots were simply too rough and imprecise. Aircraft cleaners need to work with great precision, sensitivity, and concentration. After all, if a sensitive part of the aircraft is damaged, it will be really expensive to fix!