The logic for keeping the same safe distance on a plane as you would on the ground is understandable. Cabin air circulation and ventilation in an airplane, however, are designed to disperse and redirect contaminants. Most aircraft change the entire cabin air volume 20 to 30 times more frequently than the air in an office and 5 to 6 times more often than in hospitals.
1. Airflow in the cabin
The air in the cabin of an E-Jet, for example, is renewed at least 20 times every hour. The air circulates through vents and air intakes around the upper compartments.
Years ago, during the development of the E-Jets, Embraer performed a series of CFD (computational fluid dynamics) tests and simulations of cabin air flow. The objective was to ensure that airborne contaminants were effectively directed away from passengers. In other words, droplets, such as those generated by speech, coughing and sneezing, are vertically dispersed and channeled as far away from other passengers as possible.
Embraer asserts it has found that the correct positioning of individual air vents in relation to a person’s head and the resulting air flow creates a type of curtain or air barrier. The cone-shaped flow pattern of the individual air outlet directs the particles into the air return grilles located near the cabin floor. This in turn would minimize cross-contamination between the rows, although the seat backs also serve as natural blocks for expired droplets.
2. Integrated HEPA filters
Most common droplets people throw out are between 4 and 8 microns. The heaviest ones stay close together and accumulate on surfaces such as seats and clothes. The smaller ones, however, can remain suspended. HEPA filters for aircraft, like those of all E-Jets, are are 99.97% effective at capturing airborne particles and other biological contaminants as small as 0.3 microns.
Embraer is now making the HEPA filter standard on all Praetor 600 and Praetor 500 aircraft as well as approving the use of MicroShield360, a preventative coating system that, when applied inside the aircraft, inhibits the growth of microbes on the surfaces.