Sizing a Cargo Drone Route: The Four Numbers That Matter

Most cargo drone enquiries arrive as a paragraph of context with no numbers. Four figures are enough to size a route properly — here is what they are and why each one changes the answer.

1. Payload per sortie

In kilograms, including the release hook, sling and any packaging. This is the single biggest driver of model selection, and the one most often overstated.

Be honest about the routine load rather than the maximum. A route that occasionally moves 300 kg but usually moves 120 kg is a 200 kg class route with an occasional larger job — not a 450 kg class route.

2. Route distance

One-way distance from launch point to drop point, in kilometres. If the aircraft must return with a load, state that too — a round trip carrying payload both ways is a very different requirement.

Distance and payload trade directly against each other. A platform at maximum payload has very little range left; the same platform at half payload covers considerably more ground.

3. Site altitude

Metres above sea level at both the launch and drop points. Air density derating is not a minor correction — above 2,000 m it can remove a third of rated payload.

If launch and drop differ significantly in elevation, give both. The aircraft must be able to hover with load at the higher of the two.

4. Ambient temperature

Typical daytime temperature during the operating season. Hot air is less dense than cold air, so altitude and temperature compound. A 2,500 m site at 30°C behaves like a higher site on a cold day.

This is why a manufacturer quoting a single payload figure without asking about temperature is not doing the calculation properly.

What you get back

With those four numbers, a competent team can tell you the recommended model, the battery configuration that suits your sortie pattern, an expected payload at your site conditions, and a realistic sorties-per-day figure.

That is a route assessment. It is more useful than a price list, and any serious manufacturer will provide it before asking for a purchase order.