How do carriers ensure proper cleanliness in aircraft cabins? And what should one do to avoid catching an infection during the flight? Let's listen to the advice published by BBC Future.
Some of us may assert, based on personal experience, that some airlines do not particularly care about cleanliness aboard their aircraft. The author of these lines once barely endured a long flight with a stopover in Miami, on a plane whose cabin had not been cleaned for many days, or even weeks.
“The problem is that a large number of people simultaneously occupy an enclosed space for long periods of time,” says James Barbaree, deputy director of the Auburn University Food Safety Center in Alabama. “We all carry germs – on our skin, clothing, and inside our bodies. Some of them are transmitted to other people, and bacteria multiply in dirt.”
Last year, Barbaree and his colleagues at the university published the results of a three-year study, according to which dangerous bacteria such as methicillin-resistant Staphylococcus aureus, Escherichia coli, and streptococci can survive for several days on armrests, tray tables, window shades, seat back pockets, and metal parts of lavatories. The Barbaree team showed that Staphylococcus aureus survives for 168 hours on the material of seat back pockets, and E. coli O157:H7 – a strain capable of causing kidney failure – for 96 hours on armrests.
The main problem is that airlines are trying to simultaneously achieve two poorly compatible goals. On one hand, they strive to provide passengers with quality services, and on the other, they need to constantly increase profitability by maximizing seat occupancy and minimizing downtime between flights.
Effective cleaning of passenger aircraft cabins requires careful planning, sufficient staff, well-developed logistics, and prioritization, says Adam Taylor, executive vice president of Air Serv, a company that provides, among other things, cleaning services. Air Serv receives from airline clients up-to-date information on the exact landing times of aircraft, their parking positions, and estimated departure times for the next flight. This helps coordinate the work of cleaning crews and optimize the use of available personnel and equipment. Air Serv tracks the cleaning process using GPS, and the results are checked by on-site supervisors.
Other cleaning companies use similar algorithms. The firm Huntleigh USA uses a system called E-Clean, which tracks the work of each member of the cleaning crew, and provides clients with access to real-time information on the time it takes to clean an aircraft and the extent of the work performed.
The thoroughness of cleaning depends on the type of aircraft, the duration of the next flight, the time available to the crew before the next departure, as well as which airport is involved and when the cabin was last deep-cleaned. Flight arrival delays, weather conditions, and peak airport traffic periods also play a role, says Taylor. Gaps between domestic flights are usually short, so less time is available for cleaning the aircraft than for international flights.
Under time constraints, cabin cleaning is carried out in a minimal, basic scope. The crew focuses on high-priority tasks – first and business class cabins, galleys, and lavatories. Other cabin elements receive cosmetic cleaning – usually meaning the crew only vacuums the economy class floor, collects trash, and, if time permits, wipes down tray tables with an antibacterial solution. Meanwhile, economy class seats do not receive special attention.
When an aircraft stays at the airport overnight, the cleaning company has time for a more thorough cleaning. And finally, periodic deep cleanings are conducted, during which the cabin undergoes radical cleaning.
“Each airline has its own cleaning rules depending on the aircraft type, and the thoroughness of the procedure depends on how much time the crew has,” says Taylor. For example, German Lufthansa conducts deep cleanings every 500 flight hours. At Singapore Airlines, each cabin undergoes a thorough cleaning once a month – with attention also given to equipment such as ventilation openings.
The cleaning crew knows what type of aircraft they will be cleaning, how much time they have, and where the next flight will be. Nevertheless, cleaners still have to work under time constraints.
In the case of a quick turnaround domestic flight, cabin cleaning can take less than 40 person-minutes, while a larger aircraft operating an international flight sometimes requires more than five person-hours, says Taylor. “Typically, for cleaning a double-deck Airbus A380 of Lufthansa, preparing for departure at Frankfurt Airport, a crew of eight cleaners takes about two hours,” says an airline representative, adding that the time spent on cleaning depends on how clean the cabin is before it begins.
Unsurprisingly, lavatories receive special attention. They are very small spaces, but they are used constantly. According to Taylor, the level of cleanliness of lavatories during flight often decreases noticeably.
However, not all airlines thoroughly clean toilets in between short flights. Some aircraft may make two or three short hops without cleaning the toilets or emptying the waste tanks, says Lars Barsoe of Vestergaard, an Illinois company that develops, manufactures, and services airport equipment. This cost-saving method can actually lead to additional expenses – unemptied waste tanks mean extra weight, which in turn increases fuel consumption. And if the tanks overflow and the toilets break down, flight attendants will have to deal with unhappy passengers.
Some aircraft manufacturers, including Boeing, design toilet systems so that the volume of circulating technical fluid for flushing is minimal – thus leaving more room for waste collection. However, such systems "require more careful cleaning due to the problem of unpleasant odor," says Barsoe.
Special cleaning agents are used to clean and disinfect toilets. The procedure itself typically takes less than 10 minutes per toilet. Another 10-15 minutes are needed to drain the waste from the tank into a special truck and fill the tank with clean liquid.
The methods used today for cleaning aircraft have hardly changed over the last 25 years, although quality control has become much more effective, says Barsoe.
The International Air Transport Association IATA recommends that member airlines always keep onboard toilets "in a state of perfect cleanliness." European companies on domestic flights adhere to strict requirements for air and water quality onboard. There is also a guide to aircraft cleaning issued by the World Health Organization, although it mainly calls for keeping the water supply onboard fresh and provides recommendations in case of medical emergencies during flight.
As for the cleanliness of airliners in general, there are virtually no specific standards. Taylor says that airlines need to develop their own standards and require cleaning companies to comply. Barbari believes the current situation is unacceptable: "A broader set of standards regarding the cleanliness of commercial aircraft cabins needs to be adopted. Rules and cleaning methods need to be improved to minimize the risk of spreading bacteria and viruses onboard."
And what can passengers themselves do to avoid catching a dangerous virus in flight?
• Wash your hands before leaving the toilet, says Michael Zimring, director of the Center for Extreme Environment and Travel Medicine in Baltimore, Maryland.
• The surfaces of toilet door handles are literally teeming with germs, so you should not use the toilet right before eating.
• Bring an alcohol-based antibacterial hand sanitizer – the cleanliness of water in toilet taps often leaves much to be desired, warns Zimring.
• And to open and close the stall door, it's best to use a paper towel.
• It's better to wash your hands with alcohol-based germicidal soap after every pass through the cabin, he continues, "unless you have such a good sense of balance that you don't have to grab seat backs in flight to keep your balance."
• The tray table should be wiped with a wet wipe – especially considering that some passengers with infants use such tables as changing pads.
• Finally, don't forget that dehydration occurs at altitude, so it's necessary to drink plenty of water during the flight, preferably bottled.
However, perhaps one shouldn't be too critical about the cleanliness of aircraft cabins – at least, they are cleaned fairly regularly. That can't always be said about personal cars and personal devices, including the mobile phones we use every day. Humans have to live in a world with germs, so we should all make a little more effort to keep the most harmful ones at bay when possible.