October 9, 2020, ©. Leeham News: We interrupt our series about hydrogen as an energy store for airliners to go back to our previous theme for a Friday or two: Do I get COVID in airline cabins?
IATA, Airbus, Boeing, and Embraer did a joint presentation yesterday about their latest knowledge about COVID and flying, and with the Pandemic entering the second wave in many countries it’s a timely subject.
When we covered the risk of being infected with SARS-CoV-2 in our series that ended 18 July we made several assumptions based on limited evidence around the risk of being infected while flying.
IATA (the airlines’ association) and the OEMs have been busy adding knowledge to what we could present in May/June/July. We have been briefed on their results over the last weeks and yesterday IATA hosted a webinar where it was all revealed. Let’s start with IATA’s statistics.
IATA has been analyzing and collecting statistics on what can be plausible in-flight infections since the Pandemic began, Figure 1.
Of 1,2 billion passengers that have flown, IATA finds 44 plausible cases of in-flight infections. Observe that the statistics include the early phases of the Pandemic with March having the most infections of passengers during the flight (Secondaries) by infectious passengers who boarded the plane (Primaries). This is also the period when mask-wearing was not universally adopted.
The statistics are at the same level as the probability of being hit by lightning. But there is a probable rate of infections that are not in these figures. Here is IATA’s comment to the figures:
“The risk of a passenger contracting COVID-19 while onboard appears very low. With only 44 identified potential cases of flight-related transmission among 1.2 billion travelers, that’s one case for every 27 million travelers. We recognize that this may be an underestimate but even if 90% of the cases were un-reported, it would be one case for every 2.7 million travelers. We think these figures are extremely reassuring. Furthermore, the vast majority of published cases occurred before the wearing of face coverings inflight became widespread,” said Dr. David Powell, IATA’s Medical Advisor.
Readers of our Corners know we identified the largest risk when flying, not as during the flight itself but when boarding/deboarding. These figures include these phases.
Why are the infection figures so low? All three airliner OEMs have done independent studies of in-flight infection risks with slightly different methods. All three have used the advanced CFD tools they use when designing their cabins.
They have runs hundreds of simulations and studied the spreading of a coughing event from an index passenger (called a Primary passenger in Figure 1) to other passengers back and forth.
The OEMs have all three reached similar results. We will go through them in detail and present their methods and figures, but here a summary of their findings:
The results from all three OEM confirm what we said May to July in our COVID series. The risk of being infected in-flight is very low. Even if you fly for hours. We shall note the OEM simulations cover the flight phase. This is what they control by their cabin environment.
The risk of being infected during the complete flight (including boarding/deboarding) is higher, but still low. IATA’s statistics cover the whole flight, boarding, flight, deboarding.
IATA has research that shows 80% of passengers fear sitting next to a COVID infectious person during the flight. This is the primary fear.
The next fear is touching a surface where an infectious person has left viruses that you can get COVID from. As we have written before, we have yet to find a study that confirms infections via the contact path.
This shows we cannot follow our instincts when it comes to COVID infection risks. We focus on the low-risk areas and disregard the high-risk ones.
We have referenced simulations that show the boarding and deboarding phases as the high-risk phases when flying. Boarding and deboarding are procedures where the airlines make all the difference. Their procedures and discipline executing these must now be the focus going forward. They suffer from the non-flying of their customers and they hold the key to getting customers to return to flying with confidence.
We must quell the type of headline-grabbing articles in our media where a half-baked University CFD simulation shows how we all get COVID during flight. The evidence from our OEMs shows this is indeed not the case. This shall now lay these kinds of articles to rest.