The novel coronavirus pandemic has forced the entire aviation industry to change at a moment’s notice and re-think formerly benign issues such as how flight decks are wiped down and whether cabin air systems, as designed, are sufficient for protecting those onboard. The European Union Aviation Safety Agency (EASA) addressed both issues as part of a safety information bulletin (SIB) series aimed at limiting the spread of the COVID-19—but not without creating some uncertainty.

EASA’s SIB urged operators to crack down on pilots and cabin crew members using their own cleaning products on aircraft. Using unapproved cleaning agents can damage surfaces or mix with other cleaning agents to create fumes that could endanger passengers and crew members, the agency says. 

“Aircraft operators should, to the practicable extent, provide appropriate and sufficient disinfectants (e.g., disinfectant wipes) for all crew members, and establish appropriate procedures/guidance on their use, making sure that all possible touch points and transmission-capable surfaces are appropriately treated,” EASA says. “This should occur before flight crew compartment and cabin preparation, with emphasis on ensuring all aircraft systems are correctly set before use.”

Approved procedures and cleaning agents are discussed in more detail in other agency guidance and recommendations from the European Center for Disease Prevention and Control, EASA says.

EASA’s call came on the heels of an Air Line Pilots Association (ALPA) plea to the FAA for mandates aimed at U.S. operators. The FAA in mid-March FAA issued advisory material on how operators can protect front-line employees and passengers during the pandemic, but ALPA says more is needed. In a March 31 letter to FAA Administrator Steve Dickson, ALPA President Joe DePete said that some airlines are using cleaning agents that do not meet U.S. Centers for Di-sease Control and Prevention guidance.

“We are aware of airlines claiming to have cleaned aircraft with alcohol-based disinfectants that fail to comply with the minimum 70% alcohol-based solution,” DePete wrote. “The FAA should make airlines aware of their obligation to stringently adhere to these standards. We suggest including a list of specific products recognized to disinfect for the virus causing COVID-19.” FAA has issued recommendations to operators, but as of April 8, had stopped short of mandating them. 

ALPA leaders met with top FAA officials on April 8 and came away less than satisfied.

“Unfortunately, the FAA is refusing to act, putting flight crews and the flying public at great risk,” DePete wrote in a letter to Transport Department Secretary Elaine Chao. “This bureaucratic inertia needs to stop—and action must be taken now to protect lives.”

In the U.S., flight attendants were raising novel coronavirus-related cabin health concerns well before the World Health Organization declared the situation a pandemic on March 11. The Association of Flight Attendants urged hand sanitizer stations at airports and in aircraft and provision of kits for flight attendants with non-latex gloves and N95 masks, among other precautions. 

EASA’s operational guidance also tackled minimizing the virus’s presence in cabins. Aircraft with High Efficiency Particulate Air (HEPA) filters in their cabin air system are well-equipped to minimize spread of the novel coronavirus, but those without should consider minimizing cabin air recirculation, the agency concludes. EASA’s latest information on preventing the virus and the COVID-19 illness it triggers—updated April 7—revises previous guidance that recommended using air conditioning, which draws in fresh air, as much as possible.

“Whenever performing commercial air transport of passengers during the COVID-19 outbreak, aircraft operators employing recirculation of cabin air are recommended either to install and employ HEPA filters, according to the manufacturer specifications, or to avoid the use of cabin air recirculation completely,” the agency says. EASA adds that safety-critical functions such as avionics cooling should be factored into any decision.

Recycling air lessens the load on air conditioning systems, which on most aircraft use air diverted from the engines. While this provides fresh air, it also reduces engine efficiency. Shutting off recirculation taps the air conditioning system, putting more fresh air through the cabin. 

HEPA filters “have demonstrated good performance with particles of the SARS-Cov-2 virus size (approximately 70-120 [nanometers]),” EASA explains. HEPA filters are standard on some aircraft—but not all. Suppliers including Donaldson and Pall Aerospace have developed retrofits for most transport category aircraft.

Even when using HEPA filters, EASA suggests operators boost fresh air intake by setting fan pack flow settings to “high” or the equivalent setting that increases fresh air flow.

“Operators should confirm with the aircraft manufacturers the practice of selecting the configuration high pack flow and follow their instructions for continuous use,” the safety agency adds.