On board and inflight is one of the safest indoor environments from a Covid-19 transmission perspective. But that doesn’t mean that travel is safe. Most planes (but not smaller regional jets and turboprops) have HEPA air filtration that’s highly protective.
That doesn’t mean the virus doesn’t spread. Often when this and other viruses are attributed to flights it’s likely spreading at airport security, in the gate area, or on the jet bridge. These are places where passengers congregate closely together and where the air isn’t filtered as well. And when you’re boarding an aircraft that’s powered down you’re not getting the full protection, either.
United Airlines solved the issue of passengers sitting together during boarding and deplaning without the benefit of rapid refresh of outside air and top quality air filtration by running the auxiliary power unit. That doesn’t help in the gate area or on the jet bridge, however.
Delta has announced a different tact. They are “replac[ing] the current air filtering systems that pump outside air into our jetbridges and parked aircraft with LEED Platinum MERV14 filters” by mid-month. This will happen at “[m]ore than 600 gates at 31 airports where Delta operates – with plans to expand to more airports in the months ahead.”
Cranky Flier thinks this is overkill.
Of course they have a higher risk of transmission because they don't have HEPA. But you're not there for long, boarding is done in small groups, and everyone is wearing a mask. This seems like overkill.
— Brett Snyder (@crankyflier) September 10, 2020
I’m glad to see improvement and investment, but I’m not all that impressed by Delta’s use of MERV-14 filters which are several grades less effective filtering viruses than HEPA filters. On the other hand most office buildings use filters with a lower MERV rating, and many air handling systems aren’t designed for ratings this high.
I like that they’re experimenting and innovating aggressively. They were first out with electrostatic spraying, other U.S. airlines saw them do it and copied, as a United executive admitted to me. Now about those TSA checkpoints…