ANDURANCE turns one large rotor with three small propellers at the blade tips. What you get: more endurance, a gentler downwash under the machine, a machine designed to be quieter, and autorotation if power fails.
A multirotor spreads its weight over several small discs. ANDURANCE spreads it over one large disc. Lower disc loading means less power to keep the same kilo in the air, hence more endurance, and a gentler downwash under the machine.
The rotor turns slowly; the tip propellers do the fast work. There is no reaction torque to counter, and after a power failure a spinning rotor comes down in autorotation.
The architecture is protected by US patent 10,864,989 B2.
Momentum theory, from published dimensions: a 175 kg multirotor on four 1.57 m discs.
On a helicopter, a central engine turns the rotor through a gearbox, and a tail rotor counters the torque. On a multirotor, four to eight small propellers blow hard to carry the load. ANDURANCE works differently: three small propellers at the blade tips drive a single large rotor. The rotor is pushed from its tips, not driven from its centre.
A large disc moves a lot of air slowly: to carry the same weight it needs less power than several small discs. And because the motor sits at the blade tip, the blade carries no drive torque: the 6.5 m rotor stays light. The energy on board lasts longer.
The large rotor turns slowly and only three small propellers work fast, where a multirotor drives four to eight heavily loaded propellers. ANDURANCE is designed for a quieter acoustic signature, an asset for defence missions as well as for farms' neighbours. We will publish measurements after flight testing.
The air comes down about two and a half times slower than under a large multirotor of the same mass (calculation above). For spraying or whitening, a moderate downwash helps put the product where it belongs.
The tip propellers drive the rotor directly: the hub passes no torque to the fuselage. No tail rotor, no gearbox to service, fewer mechanical parts that wear.
If one blade-tip propeller stops, the other two keep driving the rotor: ANDURANCE is designed to continue flying in degraded mode and reach its landing area. If all power is lost, the spinning rotor comes down in autorotation and slows the descent, like a helicopter's.
The same principle flies our agricultural drone, which has already carried 15 kg, the 50 kg heavy-lifter under construction, and the large propeller of the ANDIR airship.
| ANDURANCE | Multirotor | Helicopter | |
|---|---|---|---|
| Lifting rotors | 1 large rotor | 4 to 8 small rotors | 1 large rotor |
| What turns the rotor | 3 blade-tip propellers | one motor per propeller | a central engine and a gearbox |
| Tail rotor | no | no | yes, or two counter-rotating rotors |
| Downwash under the machine | moderate | strong | moderate |
| Noise | reduced, to be measured in flight | high | high |
| One motor fails | degraded flight on the other 2 propellers | quadcopter: falls; 6 to 8 rotors: degraded flight possible | single engine: autorotation |
| Total loss of power | autorotation | falls | autorotation |
| Mechanics to maintain | reduced | simple | heavy |
Comparison of principles, at equal mass. ANDURANCE heavy-lift performance will be measured in flight.
Our ANDURANCE prototypes have been flying for several seasons. The agricultural version, shown here in field trials, has carried 15 kg for 15 minutes, and flies for over an hour with a light payload: the principle is proven in flight, not just on paper.
We are building a 50 kg payload version. For agricultural spraying, it carries a 6 m boom fitted with anti-drift nozzles from the official French list, each half following the slope of the ground. It is designed for the rules in force in France since June 2026, which recognise only this category of equipment to limit drift when spraying by drone. It is also aimed at greenhouse whitening, where a gentle downwash helps lay down an even coat.
The same carrier serves logistics: resupply where vehicles cannot go, for civil and defence needs. ANDURANCE is designed for dual use.
The figures below are design targets. Flight figures will be published once testing has measured them.
Design targets, not yet measured in flight.
Future dates are targets; we will update them as testing progresses.
Sizing, 3 m blades, avionics, supported by the European ECDI programme.
DoneApplication for test-flight authorisation filed with the French civil aviation authority (DSAC) on 27 October.
DoneFirst test flights of the prototype, over a clear field.
TargetSpraying water with the 6 m boom, for a first demonstration.
TargetDeposition and drift measured in real conditions, with partner farms.
TargetFarms, cooperatives, technical institutes: we are looking for fields and partners to measure deposition and drift in real conditions. You see the results first, and discuss them with the people who designed the machine.
Carry equipment, spare parts or supplies to an isolated site, in the mountains or after a disaster, with no road or track.
Two ways of carrying are under study: the load fixed under the drone, or hung on a sling to set it down without landing.
ANDURANCE is designed for dual use: the same qualities, endurance, low acoustic signature, moderate downwash and autorotation, serve civil and defence needs alike.
For persistent observation, site surveillance or telecom relay, an airship stays aloft for a long time, provided it has a large propeller. For 10 kgf of thrust, a 30 cm propeller needs about 2.3 kW; a 2 m propeller, about 350 W (ideal theoretical values). That large propeller still has to stay light: this is what ANDURANCE technology makes possible.
Our 4 m demonstrator carries 1 kg for 30 minutes. Next target: 5 kg for 3 hours. A solar variant is under study.
Have an airship? We can study with you how to fit the ANDURANCE rotor to it. The ANDIR airship itself is not for sale today.
ANDURANCE was not born on a spreadsheet. Each version flew, broke, and taught something to the next.
First prototypes; Anemos founded in Saint-Étienne.
Full-size two-blade mock-up.
First flight tests of the tip-driven rotor.
Three-blade version flying.
Agricultural version: 15 kg for 15 minutes, seeding in the field.
50 kg heavy-lifter under construction.
Architecture protected by US patent 10,864,989 B2. Designed and built in Saint-Étienne, France. We also design custom drones, such as a multi-sensor drone for Thales.
Because that is where their effort turns the rotor most, and there is then no torque to counter: no tail rotor, no gearbox. The rotor can be large and light, hence energy-efficient.
It is a design goal: one large, slow rotor and only three small fast propellers, instead of four to eight heavily loaded propellers on a multirotor. A low acoustic signature matters for defence missions as well as for neighbours. We will publish measured noise levels after flight testing.
Not yet. First test flights are targeted for February 2027 and a spraying demonstration for March 2027. We are looking for farms and partners for field trials.
If one of the three blade-tip propellers stops, the other two keep driving the rotor: ANDURANCE is designed to continue flying in degraded mode and reach its landing area. And if all power is lost, the large spinning rotor comes down in autorotation, as on a helicopter.
It is one of the intended uses: a gentle downwash and a 6 m boom help lay down an even coat. We will offer it once the heavy-lifter is on the market.
In Saint-Étienne, France. The architecture is protected by US patent 10,864,989 B2, and the heavy-lifter's development is co-funded by the European Union under the ECDI programme.
It is possible: we can study with you how to fit the ANDURANCE rotor to your airship or aircraft, and we design custom drones.
This project is co-funded by the European Union's Single Market Programme under grant agreement No.101236201.
The development of ANDURANCE heavy-lift is supported by the European ECDI programme (Civil Drones Innovative Programme), coordinated in France by Aerospace Valley. The views expressed are those of the author only; neither the European Commission nor the ECDI project is responsible for any use that may be made of the information on this page.
Spraying, greenhouse whitening, seeding, cargo, observation: tell us about the mission, the payload and the terrain.