How to Prevent Drone Accidents while Flying Your Farm
Prevent costly drone accidents with a little forethought and planning.
Aug 9, 2016
Fly drones enough, and you’re likely going to have a mishap at some point. Whether it be a fly-aways or an “unplanned landing,” It happens to the best of us. I’m sure you’ve probably heard it before: Operator error is the number one cause of mishaps! In the effort to prevent drone accidents altogether (or at least bring likelihood as close to zero as possible), consider the following before every flight:
Aerial surveys start with a ground check.
Always power up the aircraft away from large metallic objects, sources of [electro]magnetism, and radio transmission. You’re gonna wanna put on your spectacles and thinking cap alike as you survey the area around your home, or take-off point. There may be no metal around, but what about below? Persistent problems in compass calibration might point to significant metal buried in the ground, street, sidewalk or parking lot. Likewise, radio and electromagnetic interference sources can wreak havoc with a drone’s internal sensors. In our neck of the woods, both a running oil pumpjack powered by an electric motor and particular kinds of high-voltage transmission lines each have the potential to foil the compass of nearby drones. We’ve also seen general “wonk” (that’s a technical term, kids) when flying close to higher-powered sources of radio transmission.
Calibrate where you fly.
When looking to prevent drone accidents, one of the most important and yet overlooked steps in a preflight regiment is the sensor calibration. To the credit of most hardware manufacturers, much of this happens in the background; but all the same, what’s going on behind the scenes in the autopilot computer should be at the forefront of an operator’s mind. Some manufacturers recommend that you let the aircraft “rest” on a clear, level surface for about a minute after power up, and honestly, it’s not the worst idea, even if it’s not even mentioned by the manufacturer.
Regardless of platform, when we fly missions, we always make it a point to power on and calibrate the aircraft in the environment in which we’re looking to fly: Flying outdoors? Power everything up outdoors on-site (not in your pickup, and not in the shed). Environmental swings have the potential to really confuse on-board sensors; and inconsistencies in GPS and compass can cause unpredictable (even disastrous) results!
Be skeptical of your battery.
Do not overestimate your battery. I’ve seen (and unfortunately participated in) accidents that could have been avoided if the ability of the battery had not been overestimated. Ever seen your mobile phone mysteriously go from 50% to 15% battery life? Transpose that same situation to something flying at 400ft AGL at 30 mph and I think you’ll see what I’m getting at. If you’re using old or over-used batteries or even batteries that aren’t freshly-charged, the only predictable thing about your flight will be unpredictability! Whenever there is doubt with respect to flight times, use your newest battery charged immediately before use. Curt’s collected some totally decent resources for drone battery maintenance. Take the time to review said resources; it could save your aircraft!
Cold, windy and wet days are the worst.
Any precipitation is a no-fly condition. I’m just gonna repeat that: Any precipitation is a no-fly condition. The same sorts technology that power your cell phone are in play in most commercially-available drones. Folks go out of their way to keep a phone dry, so an aircraft with the same kind of innards should be treated no differently. Likewise, for manned and unmanned pilots alike, a watchful eye must always be lent to the wind sock. For lightweight aircraft such as the DJI Phantom series, sustained winds over 18 mph are a no-fly condition. Strong gusts or even not-so-strong erratic shifts in wind are also problematic; and even if your aircraft can handle a shift in prevailing winds, a change in ground features (swaying in and shifting crops) means you may not get the survey image you’re after anyway.
Temperatures below freezing are a no-fly condition as well. Lithium battery technology gets very unpredictable as the mercury drops. The fact that there is such a thing as a LiPo battery warmer should give a would-be “polar bear pilot” pause.
You’re the Pilot in Command (emphasis on command).
If you have the controls, you have control of your aircraft. Your mobile device is helpful but usually not necessary to operate the aircraft. Especially where pre-programmed missions such as survey flights are concerned, there’s a tendency for folks to simply assume the drone is always doing the right thing, even when it’s not. If any environmental or flight condition is uncertain, interrupt flight and initiate return-to-home! This includes:
- Erratic flight
- Aircraft off-course
- Loss of Visual Line-of-Sight (VLOS)
- A dramatic change in weather
- Previously unknown aircraft encountered in the airspace
The tips mentioned here are certainly not all-inclusive, and unmanned systems technology seems to change as often as the seasons. That said, if you’ve got your own best practices to prevent drone accidents that you’d like to share we’d love to hear about ‘em in the forums (follow the link below!).