A question we are often asked regards the use of the Aero-X in agriculture. The concern is the force of the downdraft – and we think about it all the time.

In aerial application, a certain amount of downwash is a good thing – it disturbs the crop canopy enabling the applicant to penetrate deeper into the crop. This is why helicopters are sometimes more effective than dusting the canopy with an ag-plane. However the coverage rates of purpose-built ag-planes cannot be challenged when time is critical.

The velocity or wind speed is how the energy of a downdraft is characterized. As felt on the ground, downdraft velocity is proportional to the square root of the amount of weight lifted. It is inversely proportional to both the radius of the fans, and the square of the altitude flown above the ground. What this means is that altitude is the most potent term in reducing the downdraft.

Of course, for aerial application we want to get as close as possible to the crop canopy, so let’s look at the other two factors; fan radius and weight. The larger we can make the radius of the fans, the lower the downdraft velocity. The Aero-X fans are as large as is permitted for transport over public roads by trailer. Repositioning on roads is a cost-effective enabler over craft that must be based at airports.

That leaves the last term, which is weight. Through the use of composite materials and limiting equipment to only that required for low-altitude flight, we believe the Aero-X achieves the minimum weight possible for safe manned operations. When used for aerial application the intent is not to replace ag-planes. Instead the Aero-X will allow a grower to inspect crops and apply fertilizers, fungicides, and pesticides locally where they are needed – potentially avoiding or reducing full field spraying. The benefit of this approach reduces the weight of fuel and applicant carried – and the downdraft.

Ducted fans are known to have flow patterns that will be beneficial to aerial application – the flow does not recirculate as from an open rotor or wing tip. We will be characterizing the downdraft of the Aero-X during development, and partnering to test which altitudes are best suited to specific crops.