A Step-by-Step Guide to a Typical Agricultural Spray Drone Job in New Zealand
Spray drones are growing in popularity as they are, making it safer, faster, and more efficient to cover large areas with precision. However, using these drones in New Zealand comes with specific steps and considerations, particularly around compliance with Civil Aviation Authority (CAA) rules. Below is a walkthrough of a typical agricultural spray drone job, offering a basic insight into what a typical day in the field looks like.
Step 1: Checking Airspace & Compliance
Before anything else, it’s essential to check the airspace. In New Zealand, drones fall under CAA regulations, so operators need to ensure they're flying in approved zones, away from airports or restricted areas. There are online tools, such as Airshare, that help you check whether the area you're working in is clear for drone use. If you’re operating near controlled airspace or over properties that aren’t yours, you’ll need to get permissions or file a NOTAM (Notice to Airmen) unless your exposition says otherwise. If you’d like to know more about expositions and getting a Unmanned Air Operators Certificate (UAOC) for your organisation click here.
Step 2: Surveying the Land
Next, you need to survey the land to get an idea of the layout, terrain, and obstacles. This step is crucial to ensure the spray is distributed evenly and precisely where it’s needed. One effective tool for this is Pix4D, a drone mapping software. Pix4D allows you to create accurate 3D models of the area you’ll be working in, helping with the planning and quoting process before the job begins. These digital maps can be integrated into the drone’s flight planning system to ensure the spray coverage is precise and efficient.
Step 3: Mapping the Autonomous Flight
With the survey completed, you’ll then map the area for the drone’s autonomous flight. Real-time kinematic (RTK) GPS allows the drones autonomous flight to be accurate down to the centimetre by in simple terms using a combination of satellites and a local GPS base station that communicates GPS data to allow for a highly accurate GPS signal. All current Agricultural spray drones offer flight planning software, where you can set up the boundaries, designate waypoints, and define how the drone will navigate the area. It is important that this step is performed accurately as the drone will fly autonomously. This is your opportunity to identify obstacles or no fly zones to remove any possibility of an incident or collision.
It is important during this process to do a job hazard assessment, as well as pre-flight checks to ensure the drone is in proper functioning order, precautionary checks have been mitigated and the airspace is safe for take off. Once that is done you can do your chemical sign off.
During this step, you’ll also need to configure the flow rates and atomizer settings. The flow rate controls how much spray is released, while the atomizer setting adjusts the droplet size, ensuring the spray reaches the crops effectively. Smaller droplets are ideal for misting crops in fine layers, while larger droplets work better for direct saturation. This customization helps protect against drift and ensures optimal coverage based on the conditions and crop type.
Step 4: Preparing the Drone, Chemicals and Filling the Tanks
Once the drone’s flight path is mapped, it’s time to prepare the Drone and chemicals. This involves mixing the appropriate pesticide or fertiliser according to the manufacturer’s instructions, ensuring safety standards are met. The spray drone has tanks that need to be filled with these chemicals. It's important to make sure you handle the chemicals with care, using the correct PPE where necessary within the guidelines of your chemical handling certificate. Most spray drones have a capacity of 50L, this doesn’t seem like a lot but when you factor in battery life and spray rates a 50L drone can spray 5 hectares an hour.
Step 5: Launching the Drone
Now, you're ready to send the drone off on its autonomous flight. Ensure your RTK GPS home station is set up and linked correctly to your devices to allow the GPS positioning to be as accurate as possible during your autonomous flight. Then do a final check of all settings and calibrations, launch the drone from a clear starting point. All agricultural drones will autonomously follow the pre-set flight plan, spraying the crops with precision as they travel along their route.
Step 6: Monitoring the Flight
Although the drones are flying autonomously, constant monitoring is essential. The CAA requires the pilot and/or a trained observer to have an unobstructed view of the drone and the airspace around the drone at all times. This ensures the drone stays on its intended path and avoids obstacles such as trees, power lines, or unexpected hazards as mentioned earlier. Although the drone has onboard sensors they should not be relied on, it is the pilot's role to ensure a safe flight. All agricultural spray drones have real-time data provided on a mobile device, tablet or their own built-in screen allowing the operator to intervene if necessary.
Step 7: Replenishing the Drone
One of the advantages of these advanced spray drones is their ability to recognize when they’re running low on either chemicals or battery power. When this happens, the drone will automatically drop a waypoint where it paused spraying and return to its starting point. You’ll need to refill the chemical tank and swap out the batteries before sending the drone back up. Most batteries have a flight time of around 10 minutes. Once the refills and battery replacements are done, the drone will return to its last waypoint and continue its job without missing any spots.
Step 8: Completing the Flight
After completing the pre-mapped flight path, the drone will return to its home point. You should then conduct a post-flight check to ensure all areas have been covered correctly, and that no technical issues occurred during the flight.
Final Thoughts
Spray drones such as the DJI T50 Ag and XAG P100/P100Pro are being used more often in New Zealand by offering precise, efficient, and safe methods for crop spraying. By following the CAA rules and using advanced tools like Pix4D for surveying, pilots can ensure they’re operating legally and effectively.
To summarise, drone spraying is like any hard working process, it's all in the prep work. Spray drones are an emerging technology with great potential to enhance the role spraying plays in New Zealand’s primary industry. With their technological capabilities and the continual growth in awareness drones are beginning to reshape perspectives and allow for spraying to become an accurate, safe and technology based role.