Drone technology is constantly evolving and drones are no longer hobbyist or fragile machines that cannot lift heavy loads. Today, drones are able to carry more than your sports action camera or digital SLR camera, they can carry more weight of several kilos. Our team collaborated with Aerdron to create HL4 Herculift, a vehicle that can support up to 12kg payload (<25kg MTOW), an essential capability for the future of delivery drone.

The drone payload


In the world of aviation, the maximum weight that a flying vehicle can carry is expressed as “payload”. This payload includes all the equipment onboard to carry out missions: sensors, cameras, radars, lasers, parcels and armament for the military drones. The elements concerning avionics (GNSS, accelerometer, gyrometer, altimeter) are excluded from this calculation, as the hardware components of each drone (chassis, rotors, propellers, batteries and ESC controllers).Drones used in a professional, industrial or in the military are particularly interested in maximizing the payload capacities of their vehicles while maintaining a comparable MTOW (Mass Take Off Weight) to increase efficiencies. Whether to install a camera on their platform, to film, inspect and monitor, or to ship sensors and other elements useful for industrial missions, these drones are able to carry impressive loads, while maintaining sufficient autonomy to perform their missions, thanks to the capacity of the lithium polymer battery, as well as the power of their propulsion and the number of these engines, or rotors.


AERDRON and DROTEK project


AERDRON specializes in materializing innovative bespoke design concepts from the conceptual phase to a working product. The team is comprised of experienced engineers that have participated in many high profile aerospace projects in the USA, EU, and globally. AERDRON is recognized and certified as an innovative technology development company by the Spanish government. They currently working on several drone technology development programs funded through the EU Commission and the Spanish government.The aim of this collaboration was to create an autonomous device with a significantly increased payload capacity that is able to facilitate multirole payload missions. Drotek team took care of the hardware and flight dynamics tuning. Drotek flight controller is the heart of the drone system; AERDRON chose to install PIXHAWK 3 PRO autopilot for flexible and powerful autonomous flight modes.


The team also required an additional level of safety and utilized Drotek (2) DP0106 GNSS featuring NEO-M8N u-blox chip. Furthermore, this GNSS combines a high level of robustness and integration capability with flexible connectivity options. It allows to know very precisely the drone position and orientation thanks to its integrated LIS3MDL magnetometer.


Ensuring redundancies was a crucial part of the work. We thus added the Power Management Unit PRO, bringing redundant clean power supply and adding work time to the setup thanks to its double battery capacity.

The next step was to configure the machine so that it can fly with such weights which implied various steps:
• Heavy masses tend to modify vehicle’s inertia and need specific control loop tuning in order to achieve stabilization without oscillations nor overshoots
• Vibration analysis: large rotors tend to create vibration with smaller frequencies but higher amplitudes which implies a challenge for the estimator.
• High torque motors imply strong magnetic fields that can disturb compasses -> special care needs to be taken to make sure compasses do not measure magnetic fields from motors.

The HL4 Herculift drone


The drone created has a high transport capacity, strength and exceptional stability. It benefits from the latest innovations and technologies in heavy lift operations with up to 12kg of payload capacity. The HL4 is constructed from aerospace grade prepreg carbon composite materials and AL6061-T6 CNC’d metallic components to obtain the highest levels of quality and structural performance.



The Aerdron HL4 Herculift composite structure is fully optimized to achieve the highest loading / structural weight ratio possible. With a Plug & Play Payload attachment system, multiple payloads can be mounted using a universal mounting plate. The HL4 is also using a Plug & Play battery tray system to make swapping out batteries easy and quick. The HL4 Herculift comes equipped with the standard features below. It is possible to upgrade/modify it according to mission requirements. Aerdron also designs and fabricates custom gimbals, mechanisms, or mounting fixtures, or other equipment. The HL4 is delivered as a full turnkey autonomous aerial platform.





The chassis of the drone is carbon ultra-rigid aero quality and the propellers are 33 inches.
Full autonomous takeoff and automatic landing with laser altimeter.
Pixhawk 3 Pro has latest generation sensors. It features internal IMU dampening and robust and fully redundant power architecture. This reduces the amount of vibration received by the autopilot.


Discover more about HL4 Herculift on Aerdron website here.

If you are a professional and interested in drone customization for your operations, you can contact us at [email protected].