In a further attempt to reassure passengers of the safety of air travel, United Airlines is planning to increase the air flow during boarding and deplaning.
On aircraft which have the system, the HEPA filtration system recycles air every two to three minutes and removes 99.97 per cent of particles. The airline says that this makes an aircraft “a cleaner environment than restaurants, grocery stores, schools or some hospitals.”
The move will see “all mainline aircraft high-efficiency particulate air (HEPA) filtration systems” set to maximum flow during the entire boarding and deplaning process. The airline already boards passengers back-to-front and deplanes five rows at a time. The aim is for this new procedure to start for mainline aircraft beginning July 27.
On aircraft fitted with the filters, air flows downward into the cabin from ceiling vents and exits the cabin at the floor and sidewalls. That air is then routed through the HEPA filters and mixed with fresh, outside air before returning back to the cabin. According to Boeing, that top-to bottom pattern, and frequent air exchange helps minimize front-to-back air movement and reduces the potential for spread of contaminants from people, such as through sneezing or coughing.
The HEPA system replaces the entire volume of cabin air every two to three minutes by providing 50 per cent HEPA filtered, recirculated air mixed with 50 per cent outside air, which allows a constant flow of either fresh or HEPA filtered air throughout the cabin.
Since experts say that filtered air is just one part of the battle against Covid-19 transmission on an aircraft, airlines are also enforcing a strict face mask policy and also emphasising regular and thorough cleaning of all surfaces in aircraft cabins.
“The quality of the air, combined with a strict mask policy and regularly disinfected surfaces, are the building blocks towards preventing the spread of COVID-19 on an airplane,” said Scott Kirby, United’s chief executive officer.
Nevertheless, airlines know it will be an argument that does not convince all potential customers to return.
“We expect that air travel is not likely to get back to normal until we’re closer to a widely administered vaccine – so we’re in this for the long haul,” said Kirby. “And I am going to keep encouraging our team to explore and implement new ideas, new technologies, new policies and new procedures that better protect our customers and employees.”
“HEPA filters are an effective way to ensure clean air on an aircraft,” said Dr. James Merlino from The Cleveland Clinic. “United’s new strategy of running the air filtration and circulation systems at maximum volume well before passengers board and until they deplane, adds one more layer of protection. In addition to air filtration, we have worked with the airline to enact measures such as mandatory masking, health screenings, disinfection, and touchless systems, as we believe layering on precautions, more than any one strategy alone, helps create the safest environment possible.”
Other measures in place
United requires passengers to wear masks and also limits the number of passengers on board and separates passengers “where possible”. The reduction in demand has allowed the airlines to switch to a larger plane “66 times a day in May and June, for a total of more than 4,000 flights during those months”.
This, along with reduced demand has meant that the airline’s consolidated average seat factor – or the percentage of occupied seats including customers and non-revenue passengers – was 38 per cent in May; 57 per cent in June and is expected to be about 45 per cent in July, with less than 15 per cent of flights operating with more than 70 per cent seats filled.
In addition when United flights are less full, the airline’s assigns seats in a way that maximizes the space on board. If the flight is expected to be more than 70 per cent full, it contacts customers via email and through the United app to give them the option to switch to different, less full flights for no additional fees. Customers also have the option to cancel their flight and receive a credit for future travel. The airline says “To date, the overwhelming majority of customers choose to keep their travel plans the same.”