Buchanan says she felt safe the whole flight. There were few passengers on board, and Southwest employees and passengers followed guidelines. Flight attendants and passengers wore masks and socially distanced during the flight. 

But the CDC also says that “germs do not spread easily on flights because of how air circulates and is filtered on airplanes.” Delta Air Lines, Southwest, United, and American use high-efficiency particulate air, or HEPA, filters. 

“HEPA filters are a very high-intensity system of fibers that you essentially run air through to filter out an incredible amount of contaminants -- not just dust, not just bacteria, but moisture, any sort of contamination that could potentially harm or create an atmosphere in the cabin or the cockpit that could harm the passengers or the crews,” writes Zach Wichter, an aviation reporter at The Points Guy, a publication that covers travel. 

Airlines say planes are sanitized before and between flights. Airport employees use electrostatic technology, a gun-like machine that sprays disinfectant, killing most germs. The spray makes the virus less able to spread throughout airplane cabins. 

To help passengers feel safer, Delta has partnered with Mayo Clinic to test employees and advise the company on best practices for flights and for Delta’s gates and workspace at airports.

“This is a journey with no finish line -- and we know that more than three-quarters of customers, when asked, share that regular employee testing will help boost their confidence in travel,” Bill Lentsch, Delta chief customer experience officer, says in a statement. “This is the foundation upon which we will innovate and redefine future travel experiences that ensure we are delivering the safe experiences our customers expect and deserve."

Airline customers should be open to COVID-19 symptom screenings. Delta says employees could do temperature checks using thermal imaging technology or hand-held thermometers, and employees could ask passengers if they have had any symptoms of COVID-19. As of June 30, American Airlines customers will be asked if they have had any COVID-19 symptoms. Since June 10, as part of its online check-in process, United has asked customers to verify if they had COVID-19 symptoms. If they have, airlines advise people to reschedule their flights. 

As the virus continues to spread, airlines and airports encourage passengers keep up with changing information. Due to the spikes in recent coronavirus cases, United, American, Delta, and Southwest have issued new travel advisories. Passengers traveling to New York and New Jersey from Alabama, Arkansas, Arizona, Florida, North and South Carolina, Texas, and Utah should quarantine upon arrival for 14 days.