Engineers teach a drone to herd birds away from airports autonomously(techxplore.com)
techxplore.com
Engineers teach a drone to herd birds away from airports autonomously
https://techxplore.com/news/2018-08-drone-herd-birds-airports-autonomously.html
108 comments
Problem is downside risk:
drones get hacked, or someone figures out how to make the drones fly into planes, or herd birds TOWARD planes.
As a society we've been pretty cavalier about algorithmic control. Which can work well for a lot of things. But probably shouldn't be trusted (without a TON of validation and regulation, as we've done over decades with airliners) with controlling stuff that can injure people or damage societies.
As a society we've been pretty cavalier about algorithmic control. Which can work well for a lot of things. But probably shouldn't be trusted (without a TON of validation and regulation, as we've done over decades with airliners) with controlling stuff that can injure people or damage societies.
Given the number of times I've personally almost hit birds while flying small aircraft, I'll take the downside risk. Give the tower some sort of override to require the drone to land if it's doing more harm than good.
There's lots of easier ways to hack our fragile ATC system than herding birds at airplanes that I'd worry about first.
There's lots of easier ways to hack our fragile ATC system than herding birds at airplanes that I'd worry about first.
If we're discussing movie-plot scenarios, it seems like it would be much easier for an attacker to buy their own drone. And maybe figure out how to put explosives on it, too.
I'm not a big fan of conspiracy ... but I fear this is going to be an all-to-likely scenario. Someone's gonna do it and it will change aviation for a while; restrictions, mega investment in new tech i.e. special radar, anti-drone kind of stuff. Won't be able to fly a drone anywhere remotely near an airport. And there are a lot of airports!
Yes, agreed. What we've learned over the past few years that where algorithms exist, there are incentives to try to exploit them. Ad and PR firms: Google search algorithms, Twitter ranking algorithms. Political orgs: Youtube ranking algorithms, ad placement algorithms. Repressive govts: Facebook abuse reporting algorithms (done in Ukraine), Twitter hashtag algorithms, tweet ranking algorithms (bots pushing particular political tweets).
Humans may be in some ways easier to influence, but once an algorithm gets big enough, it can be worth attacking if the impact would be huge.
Humans may be in some ways easier to influence, but once an algorithm gets big enough, it can be worth attacking if the impact would be huge.
I guess. But then you have to ask why IED's are apparently only used in certain war zones? Many technically possible attacks seem not to happen all that often.
It's almost as if the risk of being killed by terrorists is blown out of all proportion to further some kind of political agenda. You're orders of magnitude more likely to get hit by a bus.
Why would anyone be a fan of conspiracy?
Or did you mean conspiracy theory? Huge difference.
Or did you mean conspiracy theory? Huge difference.
> Problem is downside risk: drones get hacked, or someone figures out how to make the drones fly into planes, or herd birds TOWARD planes.
All of these things are way harder than simply buying a drone yourself and doing illegal things with it.
All of these things are way harder than simply buying a drone yourself and doing illegal things with it.
Except if the drone you hack has the "access code" to let it fly in sensitive areas.
Drones by default have that "access code" now. There are guidelines/rules to generally keep us away from airports, but it's not a physical restriction for the device.
You can already do that with your own manually controlled drones(surprisingly, no one has done this yet). There is no need to hack the airports drones.
I think it's not surprising at all. After all, most people are sane individuals who are unwilling to pour time, money, effort and risk their life in order to simply cause suffering on other people.
There simply isn't money in downing planes, so most people have no incentive to want to do it.
There simply isn't money in downing planes, so most people have no incentive to want to do it.
The surprising was sarcasm ;)
There has benn one recorded accidental collision between a Phantom and a military helicopter (the drone exploded) and there is one guy that posted a video of a freestyle drone flying above incoming airliner on landing approach (which outraged the community).
manually controlled drones
How about we just call them "remote-controlled aircraft"... which is what they were called before the whole "drone" fad came along (and "drone" itself used to imply at least some autonomous capability.)
How about we just call them "remote-controlled aircraft"... which is what they were called before the whole "drone" fad came along (and "drone" itself used to imply at least some autonomous capability.)
Indeed. RC planes and helicopters have been around for a very long time. But all of a sudden they're potential weapons of mass murder because... They have a few extra propellers!?
Cost of upkeep and maintenance (not to mention trained personel) is going to be very high if this isn't automated.
I'm not a pilot, but at 3000 feet AGL, you have a lot more room for emergency maneuvering / diverting back to origin or alternate right?
I remember hearing something about how many small aircraft incidents occur at low altitude on takeoff or landing, partly because it's harder to recover from a stall condition (perhaps engine-out as well?) at low altitude...
I remember hearing something about how many small aircraft incidents occur at low altitude on takeoff or landing, partly because it's harder to recover from a stall condition (perhaps engine-out as well?) at low altitude...
One way of thinking about altitude is how many mistakes you have time to recover from before hitting the ground. The higher you are the safer you are - you haven't crashed until you hit the ground.
For a single-engine plane, 500' AGL depending on the plane and wind is enough to make a 180° turn and land on the takeoff runway if its clear. 1000' AGL will let you do it on just about any suitable surface at the airport - other runways, taxiways, grass clearings adjacent to them, etc - and give you a few seconds to be confused before deciding that you need to make an emergency landing.
Most birds fly quite low, and drone-based bird abatement at airports would be a safety win if done right (DO-178-B style software quality), but I've heard of bird strikes above 20,000', and been taught to expect that you're never flying above _all_ the birds.
Edited to reply directly to your 3000' comment like I meant to: At 3000' AGL, you can almost always glide to a safe landing point, unless you're over mountains or a dense urban area. But unless you happen to already be near an airport, you probably won't be able to glide to one. Glide ratios much higher than 10:1 are uncommon, so thats 5.7 statute miles. Lots of places are more than 5.7 miles from an airport.
For a single-engine plane, 500' AGL depending on the plane and wind is enough to make a 180° turn and land on the takeoff runway if its clear. 1000' AGL will let you do it on just about any suitable surface at the airport - other runways, taxiways, grass clearings adjacent to them, etc - and give you a few seconds to be confused before deciding that you need to make an emergency landing.
Most birds fly quite low, and drone-based bird abatement at airports would be a safety win if done right (DO-178-B style software quality), but I've heard of bird strikes above 20,000', and been taught to expect that you're never flying above _all_ the birds.
Edited to reply directly to your 3000' comment like I meant to: At 3000' AGL, you can almost always glide to a safe landing point, unless you're over mountains or a dense urban area. But unless you happen to already be near an airport, you probably won't be able to glide to one. Glide ratios much higher than 10:1 are uncommon, so thats 5.7 statute miles. Lots of places are more than 5.7 miles from an airport.
What kind of birds fly above 20,000 feet???
That's pretty mind blowing. The top of the list there is Rüppell's vulture, which was confirmed in 1973 to have been flying at 37,000 ft, identifiable by feathers it left behind when it was ingested by a jet engine.
Unlucky bastard. You think you're safe, 7 miles above the earth, far from any predator, when WHAM. At least it was a quick death.
Unlucky bastard. You think you're safe, 7 miles above the earth, far from any predator, when WHAM. At least it was a quick death.
> don't think many of them know the airspace system or where their nearby airports are)
Don’t you think they can’t learn that just like you did?
Don’t you think they can’t learn that just like you did?
It's not a matter of whether drone operators _can_ learn. It's more a matter of many of them _not_ learning. Why do firefighters still have trouble with drone operators running drones in areas where they are actively fighting fires? Not that all pilots are good about following the regulations all the time even though they should, but the consequences to the individual for not following FAA regulations as a private pilot are generally much higher than they are/should be for drone operators.
Sure, random drone people are a problem but in this case, I don't see why the airport themselves cannot hire trained professional drone operators. Drones opperated by the firefighters themselves might prove to be useful.
There are professional drone operators out there and they have been deployed to help out with emergencies.
I don't think they're motivated to learn.
>> The passengers on Flight 1549 were only saved because the pilots were so skilled.
Of course the engineering and planning that went into the aircraft's construction had nothing to do with it, nor did the countless government regulations dictating safety equipment and training.
These sorts of "miracles" happen rather regularly. A plane crashes near a runway totaling the aircraft, but everyone walks away. Piloting is part of the equation, but pilots stand atop an enormous pyramid of other people each contributing to flight safety. See that flight in Canada that crashed but did not catch fire. A couple decades ago that would have ended very differently.
Of course the engineering and planning that went into the aircraft's construction had nothing to do with it, nor did the countless government regulations dictating safety equipment and training.
These sorts of "miracles" happen rather regularly. A plane crashes near a runway totaling the aircraft, but everyone walks away. Piloting is part of the equation, but pilots stand atop an enormous pyramid of other people each contributing to flight safety. See that flight in Canada that crashed but did not catch fire. A couple decades ago that would have ended very differently.
all Airbus 320 will have the same safety mechanisms and industry required features, but they would have been useless without the pilotsquick response in the end
Human interaction ends up being the wildcard
Human interaction ends up being the wildcard
There are also many natural wildcards. In water landings, where you hit the wave makes a huge difference. On land, it is trees and ground features. A good pilot can maximize the odds, but there is always a huge amount of luck.
With some regularity, I encounter people who work either around pilots or on planes and consistently attempt to disqualify pilots from praise, no matter how insignificant that is to the context of the conversation. As if I would need to comment on any of Elon Musk's success to mention that his success would not have been had without the countless engineers and layers of automative tech that he's building upon. These being implicit details, and the people in those positions more than likely choosing them with no expectation that they'd be a figurehead.
Now, I only get a little of that from your comment, just enough to remind me of this impression. Where does the tacit resentment come from? Anyone else experience this?
Now, I only get a little of that from your comment, just enough to remind me of this impression. Where does the tacit resentment come from? Anyone else experience this?
Checklist Manifesto (by Atul Gawande) makes a strong case that the systems and processes in flight planning are an unsung "hero" in the consistent safety record of the complex affair that is flying. I don't think it's resentment so much as it is acknowledgement of normal human bias (to find and credit heroes), and an attempt to provide context that frames that bias in a proper and realistic way.
Sully was a hero! Is a hero! And he gets, and deserves, a lot of credit. But he was the first to say that he was just doing his job, and he means it literally. He and his copilot worked together (very effectively) to apply the proper checklists and procedures in order to effect a safe water landing and evacuation.
Sully was a hero! Is a hero! And he gets, and deserves, a lot of credit. But he was the first to say that he was just doing his job, and he means it literally. He and his copilot worked together (very effectively) to apply the proper checklists and procedures in order to effect a safe water landing and evacuation.
Hey, if those checklists and procedures were in version control we could git blame those heroes, as we should!
Well, if it is resentment then it is self-resentment, me being a pilot.
I suspect the birds would eventually ignore the drones unless the drones are made to pose an actual physical threat to them. City pigeons are so accustomed to cars and humans that they barely move out of the way in time to avoid being crushed.
Not sure why this is grey - many animals adapt to their environments very quickly. If all the drones are doing is buzzing the birds, they may very well learn to ignore them.
The drones would chase the birds away. And in cases when the birds are to be sucked by a jet's engine the autonomous drone would follow suit
> The drones would chase the birds away.
Chasing requires fleeing. If the bird knows from experience that the drone won't hurt him, then why would he flee from it?
Chasing requires fleeing. If the bird knows from experience that the drone won't hurt him, then why would he flee from it?
Because he's a bird?
It is not obvious to me that a bird will flee from anything that approaches it, regardless of past experience, simply "because he's a bird". See above about city pigeons. Or aggressive geese at the park. Or birds that get sucked into jet engines because they apparently don't consider a jumbo jet to be an obstacle worth avoiding, hence this conversation.
> Or birds that get sucked into jet engines because they apparently don't consider a jumbo jet to be an obstacle worth avoiding, hence this conversation.
The problem there is that the bird has no time to react. Planes are way faster and actually suck air.
The problem there is that the bird has no time to react. Planes are way faster and actually suck air.
Even city-dwelling pigeons have a personal space bubble that they will try to protect if possible. It may be just a foot or two but it is still there.
The smaller that bubble gets, the greater the chance of a drone actually striking a bird, which could become a major legal liability [1].
[1] https://en.wikipedia.org/wiki/Migratory_Bird_Treaty_Act_of_1...
[1] https://en.wikipedia.org/wiki/Migratory_Bird_Treaty_Act_of_1...
I'd imagine airports could get a waiver to pursue the birds for human safety. Airports are generally well acquainted with working with the government.
Chasing the birds in circles
Or maybe the drone could be equipped to zap birds with some small electrical charge. They'd learn the lesson quickly
Aircraft have beacons to stop them flying into each other, I'm not sure why they wouldn't design the drones to be able to detect them.
Well sheep have been herded by dogs for millennia and I think it's pretty rare that they actually hurt any sheep.
There are several types of sheepdog, and some do nip at livestock to keep them motivated.
https://en.wikipedia.org/wiki/Herding_dog#Herding_behavior
https://en.wikipedia.org/wiki/Herding_dog#Herding_behavior
I'm resisting with great strength to clicking that link, but now I know it exists!
Oh boy, there goes a future evening...
Oh boy, there goes a future evening...
Those sheep are domesticated and a social hierarchy exists between them and a specific dog or group of dogs. I don't think we can look at that situation and extrapolate that a flock of wild birds will "obey" a random flying robot that they know to be nothing more than a harmless nuisance.
Come to think of it, birds don't even make enough of an effort to avoid existing aircraft that are large, loud, and do pose a threat to them, which is why these drones are being developed in the first place.
Come to think of it, birds don't even make enough of an effort to avoid existing aircraft that are large, loud, and do pose a threat to them, which is why these drones are being developed in the first place.
This very much smells like fluff piece. Tech for obstacle avoidance is not yet mature to the level where it would be safe to have autonomous drones near bird path and potential busy air traffic. Add battery restrictions, wind, weather etc and you get nice vaporware demo.
My off-the-shelf $1k drone can fly fine in heavy wind and light rain. With minor mods, it could probably handle heavier rain too. Any wind it can't handle is going to discourage birds too.
What happens when the pilots come to depend on the vaporware and are no longer skilled enough to land in their own? Or when they run the avoidable risk of colliding with drones as opposed to a flock of geese?
Considering 15 minute flight time, 2 hour battery recharging time, and several miles runway circumference, I guestimate you would need around a 100-200 drone system to maintain constant surveillance around a medium size airport.
The technology is still young clearly, but:
1. Drones don't need to always be flying. Flocks of birds turn up on radar quite a lot and I don't see some early detection system for birds as impossible.
2. The flight paths for migrating birds can be predicted, reducing the need for a high presence in some directions.
3. 15 minutes of flight time is low, with some super big LiPo batteries for high performance drones you're easily getting an hour. The benefit of these large batteries is that they can be charged quickly too (charge rate based on power offered).
4. They are relatively fail safe, if the drones stop functioning you just go back to not having any real support.
5. It's likely that with some additional work, they could work on calculating the conditions that cause flocks of birds to fly towards scary sounding planes. I imagine it to be quite likely that they will only fly from certain directions given wind conditions, etc.
1. Drones don't need to always be flying. Flocks of birds turn up on radar quite a lot and I don't see some early detection system for birds as impossible.
2. The flight paths for migrating birds can be predicted, reducing the need for a high presence in some directions.
3. 15 minutes of flight time is low, with some super big LiPo batteries for high performance drones you're easily getting an hour. The benefit of these large batteries is that they can be charged quickly too (charge rate based on power offered).
4. They are relatively fail safe, if the drones stop functioning you just go back to not having any real support.
5. It's likely that with some additional work, they could work on calculating the conditions that cause flocks of birds to fly towards scary sounding planes. I imagine it to be quite likely that they will only fly from certain directions given wind conditions, etc.
Were those numbers in the article? Consumer drones already beat those numbers by half, I'd be surprised if purpose-built equipment would take a step backwards in battery technology. Also, why would you need that many drones instead of swapping batteries? I feel like I'm missing something, what do you know that I don't?
Some of the newer Lipo battery formulations can be charged at 15C or even higher, this allows for sub 3-4 minute charge times. For flight time you may be on the low side but close depending on how taxing it is herding birds, they can hover around for quite a bit longer but fast quick maneuvers take their toll.
Why would the battery charging time matter if you had a few batteries for each drone? You just manually swap or automate that process.
You can probably cut that down a bit by doing a robotic battery replacement mechanism.
you don't need a quad/octo copter to do this, it could be a winged aircraft, and those are several orders of magnitude more efficient.
YouTube video that includes a trial run:
https://www.youtube.com/watch?v=CwCPeIwumgc
Wonder if this can be used to move bird flocks away from wind-turbines ?
It's a non-existing problem tho: https://phys.org/news/2017-06-farms-bird-slayers-theyre-behe...
It might be cheaper to enclose the blades' path in cages, or add more (possibly dummy) blades to make the path appear more filled, if that's been a problem.
Maybe a ring around the tips of the blades, and the blades double as spokes. They'd be ugly, but birds would fly into them less, and power output would get slightly smoothed by the weight shifted to the exterior of the wind wheel.
Maybe a ring around the tips of the blades, and the blades double as spokes. They'd be ugly, but birds would fly into them less, and power output would get slightly smoothed by the weight shifted to the exterior of the wind wheel.
Interesting. But I’m getting tired of hearing the misuse of “teaching” in regards to software engineering. Unless the software is using machine learning, i.e neural networks, it’s not teaching. Genetic algorithm? Evolving. Anything else, programming.
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On an unrelated topic, I wonder if they could use drones to change bird migration patterns?
For instance, in Rome during Fall Season there are thousands of birds that fly by the city, taking nearby shelter in trees. It was awful walking down roadways, floor was slippery and poop was everywhere
For instance, in Rome during Fall Season there are thousands of birds that fly by the city, taking nearby shelter in trees. It was awful walking down roadways, floor was slippery and poop was everywhere
What’s worse - sucking in a bird into a jet engine or a bird-scaring drone?
Sucking a bird into a jet engine, obviously. Was this a rhetorical question?
The jet engine is mounted to a plane. It's designed to withstand bird strikes without exploding - they literally blast frozen turkeys into it with an air cannon - but they can still cause engine out situations that result in crashes or emergency landings and risk the lives of the hundreds of people on board. Not to mention the huge repair costs all that incurs.
I value the safety of the people aboard that plane far above the comfort of the birds that would like to live at the airport, to the extent that scaring millions of birds is worth doing if it's likely to save the lives of a couple hundred people. Though that's getting pretty close to the threshold at which it ceases to be worthwhile.
Also, if I was in the bird's shoes, I would much prefer to be scared by a drone than ingested into the jet engine...
The jet engine is mounted to a plane. It's designed to withstand bird strikes without exploding - they literally blast frozen turkeys into it with an air cannon - but they can still cause engine out situations that result in crashes or emergency landings and risk the lives of the hundreds of people on board. Not to mention the huge repair costs all that incurs.
I value the safety of the people aboard that plane far above the comfort of the birds that would like to live at the airport, to the extent that scaring millions of birds is worth doing if it's likely to save the lives of a couple hundred people. Though that's getting pretty close to the threshold at which it ceases to be worthwhile.
Also, if I was in the bird's shoes, I would much prefer to be scared by a drone than ingested into the jet engine...
He was pondering what's worse for a bird: extremely low occurance but surely instantaneous death, or getting to live knowing you'll be driven from your homeland to eventual extinction from robot invaders and wind turbines.
I like how there are three different interpretations of the question.
...and that the "third" one is also amusingly absurd.
(Imagine a "bird-vacuuming drone.")
(Imagine a "bird-vacuuming drone.")
I think you misread the question, which could perhaps be more clearly phrased as "What’s worse to suck into a jet engine - a bird or a bird-scaring drone?"
The bird scaring drone can be programed to stay clear of planes. The birds can't
Birds are already programmed for that. It's called self preservation.
Airplanes are huge chunks of metal that make a deafening roar. Grown men are rightly afraid of coming near one.
Airplanes are huge chunks of metal that make a deafening roar. Grown men are rightly afraid of coming near one.
> Birds are already programmed for that. It's called self preservation.
Not exactly. Bird strikes are a huge problem especially in "congested" environments, aka humans sealing up more and more former forest/agricultural land with concrete... and thus forcing the birds to airports as they usually have spacious amounts of grass land with ample space for insects.
There's a reason why bird strikes are most prevalent in city airports, simply because the birds don't have anywhere else to go. Worst case IIRC was the plane that emergency-landed in an NYC river due to colliding with an entire flock of geese.
Not exactly. Bird strikes are a huge problem especially in "congested" environments, aka humans sealing up more and more former forest/agricultural land with concrete... and thus forcing the birds to airports as they usually have spacious amounts of grass land with ample space for insects.
There's a reason why bird strikes are most prevalent in city airports, simply because the birds don't have anywhere else to go. Worst case IIRC was the plane that emergency-landed in an NYC river due to colliding with an entire flock of geese.
Are they a "huge" problem? How many occur every day? How many fatal accidents do they cause - as a percentage of all flights?
What makes the problem "huge" is the fear of bird strikes. You can read up (e.g.) on https://www.thespruce.com/how-do-airports-prevent-bird-strik....
In absolute numbers, per FAA there were 13k bird strike events in 2016, with 262 deaths+279 injuries from 1990-2013 (so about 11 deaths/year on average): https://www.faa.gov/airports/airport_safety/wildlife/faq/
Obviously most birdstrikes are harmless but everyone fears a scenario like in 2009 in NYC.
In absolute numbers, per FAA there were 13k bird strike events in 2016, with 262 deaths+279 injuries from 1990-2013 (so about 11 deaths/year on average): https://www.faa.gov/airports/airport_safety/wildlife/faq/
Obviously most birdstrikes are harmless but everyone fears a scenario like in 2009 in NYC.
Except evolution never programmed the birds to steer clear of large, fast-moving aircraft - hence the need to scare them away.
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Before they used drones they used hawks to hunt other birds. Never really heard of this being a problem even then.
Depends on the size, altitude and your affinity towards birds/drones. First wind turbines now robotic nuance drones, birds have had it to good for too long I guess.
Haha, same thought here. I think the drone would be way worse. I really don't think this is the best idea though it could work until a disaster happens.
This is classic short-sighted engineering hubris. Realistically how much statistical threat is there from birds? And how long until this design malfunctions somewhere? If this is rolled out in scale and put in use at every airport, it's going to happen.
> Realistically how much statistical threat is there from birds?
From wikipedia:
"The International Civil Aviation Organization (ICAO) reported 65,139 bird strikes for 2011–14, and the Federal Aviation Authority counted 177,269 wildlife strike reports on civil aircraft between 1990 and 2015, growing 38% in 7 years from 2009 to 2015. Birds accounted for 97%"
From wikipedia:
"The International Civil Aviation Organization (ICAO) reported 65,139 bird strikes for 2011–14, and the Federal Aviation Authority counted 177,269 wildlife strike reports on civil aircraft between 1990 and 2015, growing 38% in 7 years from 2009 to 2015. Birds accounted for 97%"
But how many did any actual damage? How many resulted in fatalities?
Guess this dog needs to start retraining: https://www.youtube.com/watch?v=-QxZv_wJ1aA
Got some bad news on that front: https://www.independent.co.uk/news/piper-dead-dog-airport-mi...
looks like it can be an effective crowd [of humans] control tool.
its starts with the innocuous birds..and then ends up herding people between flights...and protests.
This could also be used at landfills to scare away seagulls.
Unless eating from landfills harms the seagulls, why? What precious things are the seagulls taking from landfills, and why do we need landfills to remain perfectly preserved?
The seagulls eat the refuse then comtaminate the water supply with their feces.
I still don't understand your reasoning.
Do you want seagulls to not eat, never eat? Do you want seagulls to be killed?
Is the water supply adjacent to the landfills? Will the seagulls not poop in the water supply if they didn't eat from landfills, or is pooping in the water supply not a problem as long as the seagulls haven't eaten from a landfill?
Do you want seagulls to not eat, never eat? Do you want seagulls to be killed?
Is the water supply adjacent to the landfills? Will the seagulls not poop in the water supply if they didn't eat from landfills, or is pooping in the water supply not a problem as long as the seagulls haven't eaten from a landfill?
Bird scientists are already devising countermeasures.
drone learning curve
...
14 shoo birds
...
47 deliver tacos
...
7,323 fold fitted sheet
7,324 herd cats
7,325 self replicate
7,326 conquer humansAre taco copters a greater innovation than the burrito hyperloop?
http://idlewords.com/2007/04/the_alameda-weehawken_burrito_t...
http://idlewords.com/2007/04/the_alameda-weehawken_burrito_t...
Is it September already?
However, I doubt this would stop another near-disaster like Cactus 1549. They hit geese on climbout at nearly 3000 feet [0]. Thats pretty far outside of what a drone can enforce, or where I'd be comfortable having a drone flying. Current regulations prohibit them flying over 400 ft AGL, except within tight proximity to structures like radio towers.
For background, I'm a private pilot, not an airline guy.
[0]: https://en.wikipedia.org/wiki/US_Airways_Flight_1549#Takeoff...