As travel restrictions relax, will passenger demand return? Carriers and aircraft manufacturers worry that the fear of coronavirus propagation may prevent the desire for travel from growing back to profitable levels. Industry players can therefore be expected to do everything they can to boost passenger confidence.

In fact, action taken by civil aviation authorities, such as the European Union Aviation Safety Agency’s (EASA) passenger management guidelines, already sets high prevention standards. EASA’s health safety protocol notably deals with thermal screening at the airport and the use of face masks. Add the existing air conditioning systems onboard, which include hospital-type filters, and passenger health can arguably be seen as taken care of.

• Material additives and UV lights are strong contenders
• Testing has yet to prove their effectiveness against COVID-19

Nevertheless, carriers may want to show passengers they are going the extra mile to protect them. If perception is reality, how passengers feel will dictate a carrier’s revenues. Hence the business case for the numerous technologies cabin equipment suppliers are pitching.

Safran suggests seats could be fitted with transparent partition walls. Each “Ringfence” wall would leave half an armrest to each passenger, says Quentin Munier, Safran Seats executive vice president for strategy and innovation.

A lighter design includes removable partitions that could be installed by passengers at head level. They could be made of single-use, flexible textile. Removable seat covers could also be single-use.

To avoid multiple hand contacts with a single item, pedals could control seat recline and tray table position.

Where antimicrobial materials would be used, such as armrests and tray tables, QR codes would enable the passenger to gather information on the surface’s hygienic properties, says Munier.

Safran Seats launched a challenge for rapid application development, which yielded 120 ideas in two weeks, says Munier. “These are ideas, not products. We have studied feasibility and, depending on customer feedback, we will prioritize developments. While they cannot be done overnight, we are well aware time is of the essence.”

A codesign scheme, dubbed “Create with Safran Seats,” is being offered to carriers for customized solutions.

Meanwhile, the Interspace padded semipartition is to be made available for premium-economy seats this summer. Since it gives a conventional seat a cocooning factor, it was initially developed for passenger comfort. In the context of the COVID-19 pandemic, it is now hoped to provide some degree of airflow separation, although the impact on air cleanliness has yet to be measured, says Munier.

Acro Aircraft Seating is exploring a collaboration with Addmaster, a supplier of additives for materials. The idea is to incorporate the Biomaster antimicrobial technology, which has been in service with London’s public transportation system for five years, into aircraft seat parts such as armrests.

“Biomaster is proven to inhibit the growth of microbes by up to 99.99%, and it has been proven to be highly effective against viruses on porous surfaces such as textiles and paper,” says Al Roots, Acro’s head of industrial design. “When microbes land on an untreated textile or surface, they multiply. When they land on the antimicrobial protected surface, silver ions prevent them from growing, producing energy or replicating, therefore they die.”

Silver-ion technology can already be found on Tapis Corp.’s Promessa synthetic leather, which Acro uses for some of its products.

Biomaster can be added at any stage of production. “It performs best if added at the raw material stage, [then] it will last the life of the product,” says Roots. If sprayed on a textile, it can undergo up to 80 cool washes.

Biomaster should be seen as a complement for regular cleaning, Roots emphasizes.

Tests for Biomaster have yet to be conducted in two domains—retention of the materials’ physical properties and effectiveness against the COVID-19 virus.

The material must be shown to keep its characteristics in flammability and resistance to cleaning agents, for instance. Otherwise recertification would be required.

The effectiveness question is more challenging. “There is no commercially available method by which it could be tested,” says Roots. But microbiology studies are encouraging, suggesting that tests conducted against the norovirus and feline coronavirus will be valid for the COVID-19 virus.

The industry ought to standardize such trials, notes Safran’s Munier.

An intermediate solution for in-service aircraft would be spraying a coating on components such as tray tables and armrests. “The cost-effective solution will be available in the near future and in a quick turnaround time,” says an Acro spokesperson.

Initial antiviral test results have been deemed positive. “Durability testing is underway, and we are expecting results in the middle of the third quarter,” says the spokesperson. The coating can also be applied to new seat parts.

“This will go some way toward helping airlines provide much-needed reassurance to cabin crew and passengers and ensuring a heightened feeling of safety and wellness,” she says.

Another challenge is in describing the products, which can be characterized as “antimicrobial” because they act against bacteria and mold. However, U.S. regulation will not allow calling them “antiviral,” says Roots.

Light could help cabin hygiene, too. Aveo Engineering, a specialist in LED lighting, is promoting the use of visible violet and ultraviolet (UV) light for disinfection purposes.

“The 405-nanometer light is the disinfecting component of sunlight. A violet light can run all the time and be masked by normal white light. We use these lights to keep galleys and lavatories clean,” says Georg Hartl, Aveo’s quality and certification administrator.

UV-C light (at a wavelength of 275 nanometers) is for intense disinfection, but humans need to be protected. It can be used for disinfection between flights.

“Both violet and UV-C light are known for being effective against bacteria, viruses and fungi,” says Hartl.

Confirming the attractiveness of UV-C, Honeywell announced a partnership with Dimer, designer of the GermFalcon cabin disinfection device. The size of an aircraft beverage cart, it has UV-C-light arms that extend over the top of the seats and sweep the cabin. Honeywell will market and produce the system, renamed the UV Cabin System. It is said to be able to treat an aircraft cabin in less than 10 min. for less than $10.

“As the travel industry begins to recover, we know hospital-grade technology will ease passenger concerns, and that’s what we’re providing with this system,” says Elliot M. Kreitenberg, cofounder and president of Dimer. Results vary based on UV dosage and application, and testing has yet to be done specifically on protection against COVID-19.

Simulation specialist Ansys points out that UV-C disinfection works only under the “line of sight” principle. This means a surface, to be disinfected, must not be masked from the light source. The right energy setting against the COVID-19 virus stands at 600 millijoule/cm², Ansys adds.

These technologies will be in addition to high-performance ventilation systems.

The air a passenger breathes is evenly composed of fresh air from outside the aircraft and recirculated air, according to Jean-Brice Dumont, Airbus executive vice president for engineering. Recirculated air flows through high-efficiency particulate air (HEPA) filters, which are otherwise used in medical environments. “They block at least 99.9% of viruses and other microbes,” says Dumont.

The air flows downward at 1 m/sec. (3.3 ft./sec.) from top vents and flows out at floor level. Every row has its own vents. That the air flows vertically, not horizontally, limits the probability of virus dissemination.

"If you sneeze, droplets will be sucked away and in 1 min., there will be nothing left around you,” says Dumont.

A computational fluid dynamics model by Ansys analyzes the example of a passenger wearing a mask and sneezing. It shows that few droplets make it through the mask, and barely come close to any other passenger.

Despite the already high performance of HEPA filters, Dumont considers also requiring more frequent maintenance checks.