Should you’ve ever watched a tilt‑wing plane like our Aero2 hover with its wing pointing straight on the sky, you might need felt an instinctive concern: doesn’t that large, upright wing act like a sail? It’s a good query — and one which has adopted the lean‑wing household for the reason that Nineteen Sixties. The quick reply, confirmed by flight check knowledge previous and new, is no. In reality, tilt‑wings deal with wind remarkably properly, usually higher than standard rotorcraft of comparable measurement.
This publish unpacks why that’s, attracts on traditional check programmes — together with Canadair’s CL‑84 Dynavert and the U.S. tri‑service XC‑142 — and previews how we’re increasing the wind envelope for Aero2 to 30 kt (55 km/h) regular winds with gust margins on high. We’re sharing some arduous‑gained information and celebrating the ingenuity that retains these plane regular when the climate is something however.
Propwash Physics – Gusts Meet a Constructed‑In Wind‑Tunnel
The core benefit of a tilt‑wing in hover is that the whole wing sits inside a strong, uniform propeller slipstream. That slipstream acts like a wind‑tunnel transferring with the plane, smoothing out exterior turbulence earlier than it reaches the lifting surfaces. Aero2’s 1.2 m diameter propeller at hover thrust produces native circulate of 27 m/s (52 kt). A ten‑kt cross‑gust merely modulates that inner circulate by a number of %.
As a result of management surfaces and flight‑management sensors are additionally immersed in that propwash, the plane retains crisp authority; small perspective modifications could be corrected in a fraction of a second by the fly‑by‑wire system. Our totally in-house-developed flight computer systems sense the motion of the plane and replace command outputs at 100 Hz, holding properly forward of the frequency vary of typical atmospheric gusts.
Key takeaway: what appears to be like like a giant sail is mostly a moveable wind‑tunnel, already blowing sooner than most ambient winds.
Classes from the Pioneers
Each programmes recorded pilot feedback praising gust stability: “Appears like flying a Harrier on rails” (CL‑84 USN analysis report, 1973). That confidence got here from the identical propwash and management‑energy rules we apply at this time, now strengthened by digital flight management and envelope safety.
Aero2: Constructing on Confirmed Foundations
We’re methodically increasing Aero2’s envelope at our check website within the Swiss Alps. To date we’ve:
- Validated secure hover and transition in regular winds above 20 kt with gusts as much as 25 kt, utilizing our baseline management legal guidelines.
- Logged over 180 automated transitions with zero pilot intervention past mode choice.
- Correlated flight‑check knowledge with CFD/6‑DoF fashions that predict controllability to 30 kt regular / 45 kt gusts.
What Occurs Above 30 kt?
For a lot of logistics or emergency medical providers (EMS) missions with small/medium helicopters, 30 kt floor‑stage wind already represents a “keep‑on‑the‑floor” threshold. By assembly that mark, Aero2 can match the dispatch reliability of the plane it intends to interchange — whereas providing fastened‑wing cruise effectivity.
Addressing the “Sail” False impression Straight
“Doesn’t the vertical wing simply catch the wind and push the plane sideways?”
- Propwash dominance: Exterior gusts are diluted by a propwash already transferring sooner.
- Vectorable thrust: In contrast to a sailboat, we are able to level the thrust vector to cancel facet forces in milliseconds.
- Digital dampers: Our flight pc makes use of acceleration suggestions to anticipate and cancel gust‑induced movement earlier than the human eye can see it.
In brief, the physics are on our facet, and our proprietary avionics double down on that benefit.
Wanting Forward
Sturdy winds will all the time be a problem for vertical flight, however many years of proof plus trendy management tech present that tilt‑wings meet that problem head‑on. We’re proud to face on the shoulders of the Dynavert and XC‑142 groups as we push the envelope slightly additional.
References
[1] Jim Chung’s Ramblings – “The Canadair CL‑84 Dynavert”, 24 Jan 2024. Describes service demo in 65 km/h gusts.
[2] Vertipedia – “LTV XC‑142A Tri‑Service” (accessed Could 2025). Notes 100° wing incidence for tailwind hover.
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