SUPERB GUIDELINE FOR DRONES

As as a Hawaii commercial drone pilot based in Hawaii, I’m often called upon to fly drones during moderately high winds. In Maui we usually experience winds in the 20 knot range with gusts that can reach the 30’s and 40’s. Every time I’m assigned an aerial media capture task with wind gusts, I must assess and decide whether it is safe to fly without risking the drone, or flying in a way that is out of control or causing injury to someone. Of course, making a “no fly” call is not a good idea and typically results in an immediate loss of money in the fast-paced world of commercial drone services. A lot of the time, this high-wind flying happens over the water (shark filled salt water to be precise!) that increases the risk and the complexity. Furthermore, as you have guessed, losing a drone to the sea’s vast blue expanse of eliminates your possibility to secure a replacement insurance options like DJI Care Refresh, unless you can retrieve the drone to return it to DJI. The good news is that you usually don’t encounter obstacles over water and image transmission is rarely interrupted because of object interference. The problem is that in the event of a problem, it is necessary to first traverse a considerable distance over No Man’s Land before you even have a shot at recovering your drone.

To prepare for a planned drone shoot of, say kitesurfing, for example I do a variety of things. First , I determine whether the location I’m to fly in is in a “green zone”. This means that QR invoices t’s not within an FAA no-fly zone, or within 5 miles of any airport. It also also has legal land and launch zone within the visible sight distance from the drone’s field of operation. Then I’ll take care of the insurance, permits, and any necessary FAA clearances necessary to perform the task. Once the location is approved I look up the weather in the area, do a pre-shoot site survey, and draw up an idea of how to shoot as well as a plan for emergency situations based on the prevailing wind direction and coastline topography. After that, I hire my assistant for the shoot, as a visual spotter is required by law and is highly recommended when pushing the limits of drones’ ability to fly.

What I’m trying to find when I look up the weather is if there is going to be sun (drone shots require sunshine) and how powerful the wind will be. Also the gust factor for the wind can be important. The variability of the wind really degrades the flight experience and could result in the drone having to roll or pitch a lot more than a steady wind. Depending on the wind speed I decide if my drone can handle the upper limit of the wind prediction. Also, direction is crucial. Offshore winds carry a more risk than Onshore winds in the event of flying over water due to obvious reasons. Finally, I think about the weather conditions when deciding not only if I can fly but also the distance, what is the subject doing, what are other obstacles, how far my drone can fly, and what is a safe altitude. Kitesurfing can be a fast moving kite at the line of 30 meters so any shots lower than 100 feet need to account for this action and the risk that comes with it.

When shooting day arrives, you’ll need to assess the actual wind and weather conditions (don’t be caught in the rain), and decide whether flying or refusing fly. I usually do this prior the time of clients or other elements of production arriving so that I can make the decision with no bias. If it is a “go” situation I fly my drone in normal GPS mode up to about 10 feet and see how long it will stay in place. If it’s really cold in the area where you launch do not launch from the ground or the drone could flip before taking off. If you can hover on the ground without losing any ground, try flying to your highest shooting altitude and observe the speed of wind there. If the wind starts to take over your drone and it starts to drift away, bring it back down to a lower elevation and try to get it back. If it’s too windy to return your drone when it is in GPS mode you can attempt switching in to “sport mode” (DJI Mavic Pro series and Phantom 4 series) and fly it back to you. Be sure to be familiar with the process of switching to and flying in sport mode prior to flying. When your drone is drifting away is not a good time to read through your set-up menus for the first time. If sport mode isn’t an option and there are obstacles to avoid, you can utilize them as windbreakers. If you are flying the drone in the direction of your own in full speed but it is still blowing over the drone, you can fly it behind trees, buildings barriers, or even mountains to reach a more stable environment. However, obstacles can also increase the wind’s variability, I’ve found that using a combination of dropping your altitude and getting behind objects that slow the wind can get you from most scenarios and , at the very least, enable you to bring your drone back to ground and not in the water. If the wind is blowing away from shore and out to sea, there are a few options to recover and the wind could be as strong as 10 feet away from the sea as 100 feet up. A strong and (typically) strong offshore winds are the most likely risk in losing the drone over water and should be approached with an added level of care.

In the end, remember to be safe, not regretting it. Don’t push your drone into an unrecoverable scenario and keep numerous backup plans for the event of an emergency. Be aware of your equipment prior to flying over or through water including time and distance limits as well as the effects of wind on speed versus surface speed. If, for instance, your drone is flying at 25 MPH at its top speed and it is gusting 15 to 20 mph, it may be able to fly downwind with the speed of 45 Mph but may only be able go higher in the air at 5mph. If your drone went 1 mile downwind, ensure that you have enough battery power to allow it to return upwind at 5 Mph, which by my calculations would take about 12 minutes. Additionally “sport mode” increases speed but decreases battery life. Don’t forget to not fly your drone when it’s empty. It is possible to fly less than expected when the battery runs low and certainly increases stress levels when you’re down in the single digits and aren’t yet back to shore.

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