New Study Confirms Low Chance Of Inflight COVID Transmission

A new study conducted by the US Department of Defense (DoD) has confirmed the very low risk of viral transmission onboard aircraft. Working with United Airlines, the DoD conducted 300 separate tests over a period of six months, using the airline’s Boeing 777 and 767 aircraft. They found that the risk of transmission was 0.003% when wearing a mask, and that passengers would need to fly for 54 continuous hours to be at any risk of an infectious dose.

United 777
The study used a United 777 and a 767 to test viral transmission. Photo: United Airlines

United Airlines and the Department of Defense prove low transmission risk

In partnership with United Airlines, the US Department of Defense has concluded in-depth testing into the risk of COVID transmission in flight. The research, published yesterday, shows that exposure to viral transmission on a plane is “virtually non-existent” when masks are worn.

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Speaking at the airline’s third-quarter results presentation, United’s CEO Scott Kirby commented,

“I think that out of everything that’s happened recently, this is the most significant announcement that has come out. Those tests are indicative of what happens on every airplane. An aircraft is just a remarkably safe environment.”

The findings of the study concur with those of the three major airplane manufacturers – Boeing, Airbus and Embraer. Each undertook its own independent study into viral transmission, and each came to the same conclusion – an airplane is a very safe place to be.

300 tests over six months

The research used a United Airlines aircraft and a mannequin head to test how viral particles spread on an aircraft. The mannequin was equipped with an aerosol generator that allowed researchers to simulate coughing and breathing. Every test conducted involved releasing some 180 million particles, equivalent to those produced by thousands of coughs and way more than a typical passenger would ever be subjected to.

COVID transmission risk
The research used a mannequin head to simulate coughing and breathing. Photo: Stephanie Wade/US TRANSCOM

Three hundred tests were conducted over a six month period. Each test assumed the aircraft was full to capacity, and sensors were placed in other seats, in the galley and even on the jetbridge to see how the cough particles spread.

The results of the study showed that, on the 777 and 767 at 100% seating capacity, an infectious dose of COVID would require passengers to sit on the airplane for 54 hours. When masks are worn, there is only a 0.003% chance that passengers would be exposed to COVID on a flight, and even then, it would only be from a neighboring passenger.

COVID transmission risk
Sensors were placed around the plane to see how particles could spread. Photo: Stephanie Wade/US TRANSCOM

Kirby concluded,

“What we demonstrated with the DoD and DARPA is that on aircraft, because the airflow is from the ceiling to the floor, it’s not spreading amongst the customers.

“We’ve known some of the facts for a while. It’s encouraging to see more than coming out into the public sphere. It is remarkable how safe you are onboard an aircraft.”

The study did make some recommendations, most of which are already in place for a number of airlines. This includes boarding passengers in small groups, maintaining mask-wearing and allowing distance between passengers on the jetbridge.

United Airlines Boeing 767-322(ER) N656UA
The CEO calls on airlines to run the APU from boarding to deplaning. Photo: Vincenzo Pace |

Make sure the passengers’ benefit

As well as singing the praises of the research undertaken, Kirby issued some advice for other airlines. He called upon carriers around the world to ensure that every passenger is afforded all the benefits of the airflow system on an aircraft for 100% of the time they are onboard. He said,

“I would encourage other airlines around the world to make sure that customers have the benefit of that robust airflow system the entire time they’re on the airplane. You maximize that by running the auxiliary power unit before start boarding passengers and continue until you finish deplaning passengers.

“I’m sure we’re not the only airline that is doing that. It does cost some money, but it makes sure that 100% of the time customers are onboard an airplane, they get the benefit of that robust airflow system.”

Does this research make you feel any safer getting on an airplane? Let us know your thoughts in the comments.