WASHINGTON—The FAA is calling attention to risks that disinfection can have on aircraft interiors, urging operators and maintainers to heed manufacturers’ guidance and take extra steps to protect sensitive equipment, wiring, and other high-risk components. 

“FAA notes that although the Environmental Protection Agency publishes a list of disinfectants effective at inactivating COVID-19, the majority of the products listed may not be suitable for use on aircraft, except in very limited and localized application,” the agency said in a Nov. 4 airworthiness bulletin. 

The agency’s bulletin clarifies that aircraft disinfection is not considered as maintenance under FAA regulations. “However, the FAA advises that aircraft owners and operators should approach the disinfection process similarly to any maintenance or repair action for which improper execution may compromise airworthiness,” the bulletin said.

Among the agency’s areas of concern: fogging and misting that allows disinfectant to penetrate areas where it could create problems, such as underlying structure or fan-cooled electronics. “Running aircraft ventilation will typically exacerbate this condition,” the bulletin said.

The FAA said it recommends electrostatic spraying over fogging, because sprayers offer more directional control. “[Using] either technique with the ventilation system off will reduce the risk of unintended application,” the bulletin said. “Note that airframe manufacturers continue to assess the implications of an operating ventilation system using specific disinfectants and may identify exceptions to this general advice.”

The FAA also advises increased inspections for corrosion in any areas where disinfectants are used.

Any procedure that creates pools of liquid should be avoided, with the flight deck requiring extra caution. “Liquids can intrude into flight deck switches and seals. Excessive liquid intrusion can lead to electrical shorts in the near term and unexpected corrosion in the long term,” the bulletin said. “FAA emphasizes that owners and operators should follow, and not exceed, the disinfectant manufacturer’s instructions for application of disinfectants identified as appropriate for the aircraft by the aircraft manufacturer.”