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A Pilot Answers: Is Flying During Coronavirus (COVID-19) Safe?

Flying during a pandemic…

We’ve all been there – sitting in that comfortable middle seat, knees jammed against the seat in front, a baby crying nearby (always), and the guy across the aisle from you is coughing. Our internal alarm bells sound off, and we wish we were a thousand feet away from this person instead of being trapped in a metal (or composite) tube with them. Airplanes are not designed for social distancing, but there are other ways to compensate for the lack of space. Airlines know this, and they have taken numerous measures to enhance the safety on board and annihilate the risk of any airborne viruses being transmitted. Do these new measures work? Is flying during coronavirus safe? What are the chances that I get sick?

Have you ever wondered where the air blowing through your vent on a flight comes from?

Rumor has it that the cabin air on airliners is simply recirculated, but this is not true. The air actually comes mostly from somewhere completely different – PACKs – and is virtually contaminant-free.

What are PACKs?

Not something you bring to a picnic, PACK stands for:

Pressurization

Air

Conditioning

Kit

Modern jets have two or three of them. They are responsible for taking air from outside, pressurizing it to bring cabin altitude closer to sea level, and cooling it down after it’s pressurized. In airliners, the air is pressurized using bleed air from the engine’s compressor section, as shown below. It’s interesting to note that this air can be as hot as 500F and the PACKs are responsible for cooling it down to usable temperatures. As a pilot and as a passenger, I’m very thankful for that.

Of the air provided to the cabin, 50-90% comes from these PACKs. The rest is pulled from the cabin and run through HEPA filters before being combined with the PACK air in the air mixing unit. The resulting air is 99.97% free of contaminants, far cleaner and safer than the air in a supermarket and even in most people’s homes.

What is a HEPA Filter and what does it do?

HEPA stands for High Efficiency Particulate Air. These filters capture 99.97% of particles (bacteria, fungi, and viruses) 100 nanometers and above in diameter. For reference, one nanometer is one billionth of a meter, or 0.000000001m. The virus that causes COVID-19 is approximately 125 nanometers in diameter, which fits perfectly in the HEPA Filter’s zone of maximum efficiency. This ultimately means there is virtually no chance of the virus being transmitted through the air system of the aircraft.

What regulates the flow of this super clean air? What about that guy coughing across from me?

There is another nice term for a system that is relevant for us and the cleanliness of the air while flying – the Environment Control System (ECS). The ECS monitors and controls air quality, temperature and pressure, while ensuring that the airflow inside the cabin is constantly flowing from top to bottom (at about three feet per second) and is subsequently removed through the floor. This airflow is optimized to prevent longitudinal movement, meaning there is no spread between your row and the one next to you. This means that the air from that guy coughing across from you never gets the chance to visit you, especially in today’s face mask-required environment.

From the floor, air flows through ducts to the outflow valve, where it is sucked out of the aircraft continuously in order to maintain the correct pressure in the cabin. As a result, the cabin air is completely renewed with this fresh air every 2-4 minutes. For comparison, air in hospital rooms and classrooms is renewed about every 10 minutes and about 20 minutes in offices, and we already know it’s generally not as well filtered in the first place. Ew.

Why have I gotten sick on previous flights, and what has changed since?

You’ve most likely gotten sick by touching contaminated communal surfaces (such as tray tables) and then touching your nose, mouth, or eyes. To prevent this, airlines are now using consistent techniques to clean these high-touch points. Almost every major (US) airline uses electrostatic spraying or disinfectant fogging between each flight. One notable exception is Southwest, which cleans the interiors overnight for 6 hours, but not between flights. Mask wearing is now required on every airline and in nearly every airport, so the chances of being able to transmit the virus into the air or onto a shared surface in the first place are very low. Airplanes and airports have never been cleaner!

That’s nice and all, but does it all work?

Though I can’t speak for every airline, the one I work for (the best one, remember?) has zero reported transmissions from onboard, and with a 90% testing rate of employees, has a much lower-than-average rate of infection than the general public. My airline, like some others, blocks middle seats and cleans aircraft between every flight. Since March, I’ve personally piloted over 100 hours and flown as a passenger just as much between 6 countries on 10 airlines. I have been tested for COVID-19 6 times and once recently for antibodies, and have always been negative. Take that, COVID.

Between limiting seats sold to 60-70%, blocking middle seats, hiring additional cleaning crews, purchasing electrostatic spraying/fogging machines, modifying inflight procedures, adding hand sanitizers onboard, providing testing services to all employees, airlines are spending hundreds of millions of dollars on ensuring the airline environment is as clean as possible, all during a time where they individually are losing tens of millions of dollars per day. Why? Simply to improve customer confidence in our health and safety. So, the (short) answer is yes. It does work.