An Archer eVTOL aircraft lifts off from a helipad, raising modest clouds of dust around its landing gear. A military servicemember is seen from behind watching the aircraft. There are mountains and a pale blue sky in the background.

The knowns and unknowns of eVTOL downwash

Separating fact from fiction in the latest hot button issue for the eVTOL industry

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Release Date
February 2, 2025
The knowns and unknowns of eVTOL downwash

In the final days of 2024, the U.S. Federal Aviation Administration quietly released a technical report on its surveys of the downwash and outwash created by electric vertical take-off and landing aircraft. The report did not make an immediate splash, but by mid-January, trade publications and eVTOL detractors had picked up on one of its key findings: that hovering eVTOLs can generate “hurricane-force” levels of outwash beyond the distances that would be expected for comparably sized helicopters.

This was not wholly surprising: an influential 2023 report from the U.K. Civil Aviation Authority had predicted the same thing. But the experimental data reignited a conversation that had previously been confined to mostly academic circles. Framing of the FAA’s findings varied widely — from the restrained observation that eVTOL downwash and outwash velocities may pose a challenge for vertiport design, to the confident assertion that dangerous downwash will torpedo the urban air mobility business model. Confronted with the perception that its five-seat, roughly 5,000-pound eVTOL will generate the same damaging winds as a 50,000-pound Bell Boeing V-22 tiltrotor, Joby Aviation issued a statement to the effect that “no, it won’t.”

These questions around downwash and outwash are consequential ones for the eVTOL industry, because they directly affect how and where these aircraft will be able to operate. Yet, like so much else about this emerging industry, the evidence available thus far is too thin to support many sweeping conclusions. Although it is unlikely that downwash alone will be a deal-breaker for the industry, it is probable that eVTOL operations will require some special precautions to protect bystanders from hazardous outflows, and the specific precautions will vary by aircraft type.

In this report, The Air Current explains the surprising complexity of downwash and outwash, the helicopter industry’s mixed record in managing the related hazards, and why the downwash from some but not all eVTOLs may pose a particular risk. A primary takeaway is that the present moment offers an opportunity to improve the safety of the entire vertical-lift industry by focusing attention on a problem that has frequently been underestimated or overlooked.

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