IRRESPONSIBLE DRONE-RSHIP

The media are all about small Unmanned Aerial Vehicles (sUAV) these days, perhaps better known as “drones.” Drones add significant value to our lives and will become more important as we move forward into the future. However, with all technologies come great responsibilities. One of those responsibilities is how we operate our personal UAV/drones.

Last week in Clarendon, Texas, a newbie drone owner/operator decided to check out an antelope. The “pilot” is a self-admitted newbie, claiming he only has “20 or so flights” on his newly acquired device and perhaps that’s the reason for his short-sighted approach in flying his device close to a wild animal.

Pronghorn1

There certainly is nothing wrong with wanting to capture the antelope in a natural setting. In fact, some would be a little jealous of such terrific subjects to film. Where this endeavor went wrong is when the drone owner decided to try to film the animal at eye-level and up close.

Pronghorn6

The antelope makes an attempt to run away and the drone operator chose to chase the animal at high speed. The antelope turns and wants to check out the drone. Due to the erratic flight of the drone/poor piloting, the antelope perceives a threat and attacked the drone before running off.

Pronghorn7

Pronghorn7a

The drone doesn’t suffer much damage, but what about the antelope?

Veterinarians all over the world have made comment about the dangers propellers bring to dogs-noses. There have been a few cases of eye-loss, at least three of them infants who have been injured by propellers. In this article, several prop injuries can be seen.

DroneSelfie

It’s not as though these flying Cuisinarts are entirely face-friendly. The face shown here was cut with the same model drone as used in the antelope video. With this in mind, I approached the owner of the drone. He felt strongly that an animal’s face is tough enough to handle this sort of incident and that it couldn’t possibly harm the animal in any way.

Pronghorn9

Regardless of the drone operator’s opinion, it stands to reason that even small drones like the popular white DJI Phantom can do damage to eyes and other soft tissues whether human or beast, as evidenced by hundreds of photographs around the web.

The particular drone I was using wouldn’t break the skin on my hand…” Travis Higgins, drone pilot

This little guy has permanently lost his eye to a DJI Phantom propeller, the same model drone seen in this antelope video.

Pronghorn8

I can’t particularly fault the drone owner for being defensive; he truly doesn’t know what he doesn’t know, but hopefully the many posts on his YouTube account have informed him that he made a mistake and it won’t be repeated. YouTube certainly provides some good learning opportunities. There are many websites, pages, and community groups where new drone operators can gain knowledge and awareness of how to best manage their drone use.

But what about other drone owners? Do they “get it?” 

If recent news articles ranging from flying a drone into the side of the Empire State Building, to a drone owner attempting to get close to presidential candidate Hillary Clinton (just before he crashed it into a building as well), it would seem many drone owners aren’t understanding the impact and risk that the excitement of drones bring to the community. In this particular case, the operator continually referred to himself as a “licensed pilot who knows the FAA rules.” There are no FAA rules that apply here; common sense should prevail. Yet he’s convinced that “since he’s an FAA-licensed pilot, what he’s doing is OK.

What might have the drone operator done to not endanger the antelope while still getting great footage?

  • Learn to fly more gracefully/skillfully before putting the drone into the personal space of people or animals. The FAA recommendations are that drones are never closer than 100′ to “non-involved individuals.”

  • Never fly at an altitude or distance that is in close proximity of living beings. In this case, 10′ up would have sufficed; the image could have been post-processed in editing to crop/zoom in on the subject). Again, a topic related to learning more about the device, its camera system, and the technology.

  • Be respectful of the animal. If it runs off it likely is scared and it’s possible the drone could induce the animal to self-injury. Keep your distance. Every year, Yellowstone Park has a percentage of visitors injured or killed because they can’t recognize this rule. They, like the drone pilot in this video, think the animals are like pets and can be gotten close to.

Higgins-Pet

A final comment; the owner of this drone and video claimed his flight was not commercial as he wasn’t being paid to shoot it, but does claim the video is intended for a wildlife conservation video. Money does not need to exchange hands to be considered “commercial” by the FAA. Indeed, if this video is anything more than a couple of buddies having some fun and capturing some hobby footage, it becomes “commercial.” Given that this particular video has received attention from CBS and ABC requesting use for remuneration, and that it’s receiving coins from YouTube for play, it falls into the category of “commercial.” Any commercial video requires a 333 exemption from the FAA, and without it, it is subject to very expensive fines. Be very aware of this, as the FAA and Transport Canada are watching YouTube and social media sites, and several individuals have been charged with using drones for commercial use, although that may not have been the drone operator’s original intent.

Drone owners are very concerned about potential rules, regulations, and controls placed by the government on our technology. Unfortunately, these sorts of videos cause enough uproar that the government truly has little choice but to try to protect us from ourselves.

Be responsible. Fly within the recommendations of the FAA or your local authorities. Understand that not everyone wants to be part of your drone video.  Be considerate, be safe.

[the owner of the video has now disabled comments after receiving many negative comments about the flight]

UNDERSTANDING TURBULENCE for sUAS

 

Image result for drone crash, buildingAs sUAV/drones become more and more popular, it seems that more and more of them are striking the sides of buildings, trees, or poles without the pilot understanding why.
“It was flying fine and all of a sudden it zipped up and into the side of the building.” “Everything was great until the drone had a mind of its own and flew straight to the ground.”
“The drone was flying over the trees and all of a sudden it spun around and dropped into the trees.”

Reading forum conversations around the internet suggests this is a common, yet unfortunate and avoidable experience.

First, let’s establish that flying in GPS mode may be ineffective when very close to a building. Signal may be lost, and this could explain a few of the building strikes.

However, far and away more likely in most instances the UAV was caught in a “rotor.” These are also known as up/down drafts, lee waves, or cross-winds, depending on which aviation discipline one adheres to. Needless to say, these phenomenon do exist, and play havoc with any sort of aerial activity whether it’s wingsuiting, parasailing, skydiving, model aircraft flight, swooping, small aircraft, and particularly light-weight multirotors.

Image result for wind turbulence map
These “waves” are indicators for manned aviation and construction crews, yet the principle is
only a matter of scale.

Even when a manufacturer provides a statement of stability in “X” winds, this should not fool a pilot into thinking that the sUAS is turbulence-resistant. Given enough turbulence or infrequency of a wave, the UAV will become unstable.

It’s always better to be down here wishing we were up there, instead of being up there wishing we were down here.

The first rule is to set wind limits. Small quad-craft should stay on the ground at windspeeds of greater than 12mph/5.5 meters per second. Hexcopters should consider grounding themselves at 22mph/10meters per second. Of course, this figure may vary depending on your organizations policy and procedures manual, insurance requirements, or payload on the sUAS.

This video provides some demonstration of the cycle of the wave and how a gyro and accelerometer might cope with the cycles. Notice how all the aircraft are “cycling” in an attempt to maintain altitude and position, even as the waves of the wind rotate?

Truly, knowing about them is half the battle. Staying away from them is the rest of it. Failing the former, being able to manage the craft in turbulence is the next-best step.

A building blocks the wind on one side (windward side) and on the opposite side (leeward side) the wind will pay all sorts of havoc with any flying object. Winds will extend in distance up to four times the height of the obstacle, and two times the actual height.

Understanding Turbulence 2

40×4=160 feet. Therefore, for 160’ beyond the obstacle at ground level, your multirotor is at risk for catching either a down draft or an updraft.

Huh?

OK, say there is a building that is 40 feet in height, and you have a medium wind blowing. Gusting or steady, it makes no difference.

40×4=160 feet. Therefore, for 160’ beyond the obstacle at ground level, your multirotor is at risk for catching either a down draft or an updraft. Either way, the airframe/hull is not in clean air. In extremely high velocities (high winds) the ratio of obstacle/distance may be as great as 15X (of course, a UAS would likely not fly in these winds)!

In terms of height, depending on wind velocity, the UAV may have to climb as high as 80’ to find clean air above an obstacle. yet at 80′ AGL, the winds are likely entirely different as well, depending on the weather and other obstacles in the area.

The air goes over the obstacle and is “pulled” to the ground (downdraft), where it then “bounces” upward (updraft) and tries to resume its level flow.

These phenomena are entirely independent of  sinks,thermal rises, dust devils, and the like.

This also occurs in natural/unbuilt up areas. Trees, canyons, ridges, rock-lines; any large object will incur rotors. Avoid them. It’s virtually impossible to determine exactly where the down draft vs. the updraft may be occurring, and the location of these dirty winds will change with swind velocity.

Understanding-Turbulence-3

FLYING IN URBAN ENVIRONMENTS

When wind flows between buildings, the mass of the air/gas is compressed. This results in an increase in velocity. Think of squeezing hard on a tube of toothpaste, compressing the contents through the tiny hole in the end of the tube. This increases the speed/velocity at which the toothpaste squeezes out. The same thing occurs with moving air between buildings or other solid objects.

Depending on the wind speed, the increase may require as much as 4-10 times the distance before the winds return to “normal” velocity seen before the gap or corner.

Image result for Wind
Image courtesy of Rheologic

Ground winds and winds “aloft” (true winds aloft are beyond the reach of most UAS operations) are rarely equal. Winds at 50′ are rarely the same as winds at ground level in an urban or suburban environment.  Even small berms in the ground can cause jarring turbulence (as shown above) that settle in the low areas. These urban “microclimates” can be very problematic for light weight UAS in required-precision environments.

Turbulence

Here is a more complex example of winds blowing at 22mph in an urban environment.

Complex Winds.JPG

complex winds 2

Compression of the flow due to building dynamics push the wind into more than 40mph in some areas. While the overall winds, and reported winds in the area suggest that the windspeed is perfectly acceptable for most commercial aircraft, turbulence and accelerated velocities within tight areas are far beyond the risk limits of most small UAS’.

Flying from warm sands to flying over water on a hot summer day may also create challenges to smooth and level flight.

DUST DEVILSImage result for dust devil

Dust devils are summertime phenomena that can be very dangerous to humans anywhere a UAS may be flying. If they happen in a city, there is usually ample evidence of their existence, as debris flies high in the “funnel.” These nasty actors can show up anywhere there is hot asphalt, sand, dirt, and if that mass of rapidly moving air connects with a cool surface, they can turn violent very quickly, slinging a sUAS far from its intended flight path.
Image result for dust devil Image result for dust devil

Dust devils in the Nevada desert can be frightening, especially when two or three combine into one vortex.

If by chance a dust devil is seen climbing in the distance, prepare to bring the aircraft home and land. If the dust devil is anywhere near the vehicle, climb in altitude while moving in any direction away from the dust devil. They are usually very short-lived.

Image result for dust devilImage courtesy Washington Post

How do we avoid getting caught in turbulent air? The long answer is “experience.” Flying in these challenging spaces teaches us to find the lee, based on the behavior of the UAS, which will always be slightly latent to the wind.
The short answer is to study environments. Look at the wind indicators that might normally be missed.  Learn to read the environment; it’s not hard once one begins to look for the details around buildings, trees, brush, monuments, chimneys, and other ground obstacles.

Two standard practices that may save pilots from troubles;

  • Always use a windmeter/anemometer, and check the winds frequently in midday flights.
  • Have a corporate or personal policy of a hard-deck/stop speed.  This eliminates wishy-washy/should I/shouldn’t I decisions in the field.  Our cap for teaching students with a Hexcopter/Yuneec Typhoon H is 16mph. If a gust crosses 16, we immediately stop, and wait it out to determine the wind trendline.

Another practice (although not standard) is to put a 5′ stream of crepe’ paper on a stick at eye level or so. This WDI, or Wind Direction Indicator, will immediately demonstrate changes in windspeed or direction, both clues that the weather may be rapidly shifting.

Determine distances from obstacles as accurately as possible prior to flight in order to best understand where the rotors will occur.  Doing so goes a long way to maintaining control and safety when the drone is in flight. With a bit of experience, one rarely needs to worry about obstacle turbulence.

Happy flights!
~dse