Visual line of sight ?

[R.Perry]

I may have asked this question before, if so I"m asking it again. Each persons vision is a little different, mine is still 20/10, I have tested each of the drones to see how far I could keep them in sight. The Inspire 2 is about 2500 feet and it is a spot in the sky, the Mavic is about 1700 feet, and it appears as a spot.
I had a new observer the other day and she couldn't see the drone at 1200 feet, and that amazed me. I didn't want to embarrass her so I didn't make any comments so I obviously don't know what her vision was other than not good.
So in essence line of sight for one person isn't the same as it is for someone else. I haven't read anything regarding what big brother considers max line of sight.
Not only that, different drones and sizes are going to have different visual ranges.

Does anyone know if there are any standards for distance set, if not what would be a prudent average?

 

[shooter]

I may have asked this question before, if so I"m asking it again. Each persons vision is a little different, mine is still 20/10, I have tested each of the drones to see how far I could keep them in sight. The Inspire 2 is about 2500 feet and it is a spot in the sky, the Mavic is about 1700 feet, and it appears as a spot.
I had a new observer the other day and she couldn't see the drone at 1200 feet, and that amazed me. I didn't want to embarrass her so I didn't make any comments so I obviously don't know what her vision was other than not good.
So in essence line of sight for one person isn't the same as it is for someone else. I haven't read anything regarding what big brother considers max line of sight.
Not only that, different drones and sizes are going to have different visual ranges.

Does anyone know if there are any standards for distance set, if not what would be a prudent average?

There is no standard because everyone is different.

If you can see it, it's within your line of sight.

If you can't, it's not.

Simple as that.

 

[clolsonus]

I'm interested in hearing other people's thoughts on this as well.

In defense of your V.O. if you take your eyes off that tiny speck 1500 feet away, it can often be really hard to sight it back in again. Some of that can be improved with practice and experience for where and how to look for things in the sky, but it's never as easy as just being able to see the speck ... you have to find it first (and it's easy to lose it unless you are super focused and disciplined to never take your eyes off it.) An experienced pilot (full scale) is going to be extremely skilled at locating specs in the sky. The average person not so much.

I mostly fly fixed wing. I have interpreted the line of sight rule as keeping the aircraft close enough where I can visually see the aircraft *and* judge it's orientation well enough to fly it manually (like an RC pilot) and be able to take immediate evasive action if a manned aircraft flies into the area. I can get down below the tree line to safety in like 3 seconds with an airplane.

However, most drone pilots probably can't fly manually (or at least not much) so what's the point of line of sight? If you can't quickly resolve a potential conflict using manual input, then who cares if you can see a speck or not? I know you (R.Perry) have a ton of experience including a ton of full scale pilot experience so what you do may not be what the typical drone operator would do. If I take my DJI controller and pull the left stick all the way down, the phantom is going lazily and gently begin to let itself down ... perhaps no where quick enough for an emergency situation.

People doing real estate photography maybe would never run into this situation, but people doing ag or construction mapping certainly could.

Question for the group: So you send your phantom off on a mapping mission and it's a little spec in the sky way over yonder ... possibly [a tiny bit] behind a tree line for just a short bit of the mission. Some scud running seaplane, or a piper cub, or whatever pops over the horizon out of no where. What do you do? If it looks like it might be close ... how does a typical dji driver handle the situation? My lab purchased a phantom a few months ago, and the realities of operating a phantom safely are a lot different from how I've been managing my fixed wing operations.

Curt.

 

[R.Perry]

Curt you make some very good points, and you are correct when it comes to construction and mapping. I fly in a restricted area but that doesn't mean we won't get a life flight helicopter occasionally and in that case I hear it coming long before it arrives and I land. Maybe I to push the envelope a little on line of sight but not to the point I can't find it.
I completely lost my display one afternoon while mapping, I knew the direction of flight, so I knew what way to turn. I turned until the drone stopped moving across the horizon then brought it back. My fixed wing experience means little or nothing when it comes to these drones, and I have said it before, I think the RC guys with lots of experience have it over me any day of the week.

I do care about the drone, but more than anything I care about not endangering anyone else in the event of a catastrophic failure.

 

[BenMcCormick]

If one tied something larger than the drone on a long string that would not to affect the CG and have no wind loading, then it would be visible further out. However, it won't be considered part of the drone system, so the LOS would be the same, but it would help one to re-locate the "spot". Possibly a large sheet of aluminum wrap with holes in it?

 

[Fred Garvin]

I can see the Andromeda Galaxy.....it’s 2.6 million Light Years away......(it’s also pretty big)

 

[Fred Garvin]

If one tied something larger than the drone on a long string that would not to affect the CG and have no wind loading, then it would be visible further out. However, it won't be considered part of the drone system, so the LOS would be the same, but it would help one to re-locate the "spot". Possibly a large sheet of aluminum wrap with holes in it?

How about just stick a strobe on it? Like a Firehouse Arc2......I’ve got one and it’s seriously bright.

 

[Red90]

I’m assuming that the VLOS rules are different in the US, in the UK we can legally only fly 500m away from the pilot in any one direction anyway.

 

[clolsonus]

I'm not going to solve all the worlds problems here, but I do think there is a hole in the FAA regulations around VLOS and see-and-avoid as it relates to drones. I tried to do some googling and found one link that seemed plausibly legit: Section 107.31 Visual line of sight aircraft operation. (2019) -

Others have raised similar concerns that (a) a drone pilot might not have the perspective to properly judge an impending collision, and (b) may not be able to responsibly comply with the 'avoid' part of the requirement. It seems like the FAA acknowledged these concerns, but decided to use airspace separation as it's primary tool for avoiding collisions. In this context, it makes sense that the FAA has established a hard ceiling of 400' AGL and it's very tough to get a waiver to fly above that.

I just dug up an old fixed wing flight of mine from 2016. I was flying directly over my AMA sanctioned RC club field. I had my autopilot engaged and holding 300' AGL and a heading of ENE. In my nose cam video you can see I abruptly grab manual control, shove the nose straight down and roll hard over. A few seconds later I level out directly over our club runway at about 10' AGL heading south now. As the nose of my airplane comes up, you can see a full size helicopter flying by at probably 150' AGL from east towards west. It can't be more than a couple hundred meters south of our field. I think this would meet every definition of a close call. 5 seconds later the helicopter is out of sight over the western horizon and gone. If I had been flying a commercial phantom instead of my DIY fixed wing I doubt I could have done anything to affect my own vehicle's path in the few seconds I had to react. In the screen shot you can see the tree tops are above me and I'm right over my RC club field, but you can also see how close the helicopter passed just to the south.



So I guess this is my point or my question. I don't see any good way to take emergency evasive action in a commercial quad copter. If the answer is as simple as "we stay below 400' and they stay above 500' agl" then I'm ok with that. But that would be small consolation to the helicopter transitioning my area of operations at 150' if the worst happened.

That helicopter wasn't the first full size aircraft (and I'm sure not the last) to fly through my airspace well below 400' AGL while I have something up in the air flying. I had a piper cub come in low over the tree line from W->E and cross directly over our field. He came through so low I didn't even hear him coming until he cleared the treeline. I've probably had at least a dozen or two other times where various aircraft flew past at various altitudes and levels of closeness. Most of the time they are well above 500' or even well above 1000' and rarely do they actually cross over the area I'm operating in, but on a nice day, I'm seeing/hearing full size airplanes all the time when I'm out flying.

 

[PatR]

You bring up a good point about descent rates. “Consumer” drone FC’s and transmitters are not set up to allow operators to command a fast, or “free fall” descent rate. The FC’s severely limit rate of descent and climb while the “center loaded” throttles on transmitters cannot reduce power to a level that will permit power cut off to the motors. In effect, the only way to perform an emergency descent is to disarm the aircraft, IF the system will permit rapid remote disarming of the motors.

In creating systems that made it easy for anyone to operate the consumer manufacturers inhibited the operator’s ability to command fast descents. The DIY sector, using FC’s providing full programming access, sets up throttles where centering the throttle stick is hover, elevating the stick increases power to climb, while full aft throttle stick reduces power to a low idle speed or stopped props, essentially allowing free fall. Aside from racing and aerobatic type multirotors, the basic set up design of consumer drones prevents use of propeller thrust via pitch of the airframe to be used for increasing speed of descent.

 

[Phaedrus]

There is no standard because everyone is different.

If you can see it, it's within your line of sight.

If you can't, it's not.

Simple as that.

A little more complex than that. The FAA means LOS to mean that not only can you it, but you can also determine orientation and observe traffic and obstructions around it.

 

[R.Perry]

A little more complex than that. The FAA means LOS to mean that not only can you it, but you can also determine orientation and observe traffic and obstructions around it.

Where did you find that clarification?

 

[R.Perry]

That helicopter wasn't the first full size aircraft (and I'm sure not the last) to fly through my airspace well below 400' AGL while I have something up in the air flying. I had a piper cub come in low over the tree line from W->E and cross directly over our field. He came through so low I didn't even hear him coming until he cleared the treeline. I've probably had at least a dozen or two other times where various aircraft flew past at various altitudes and levels of closeness. Most of the time they are well above 500' or even well above 1000' and rarely do they actually cross over the area I'm operating in, but on a nice day, I'm seeing/hearing full size airplanes all the time when I'm out flying.

I'm just curious, couldn't you hear the helicopter long before it got that close? Years ago when I was crop dusting there was an RC field close to one of the farms, I always avoided flying close to it, and had no need to. Not only that most of the RC folks were out on the weekends and I didn't work weekends. Both pilots (UAV and Manned) must take responsibility for the way they operate. To me unless that helicopter pilot had reason to be that close to an RC field he wasn't operating in a prudent manner in my opinion. Done lay all the blame on the UAV pilots.

 

[PatR]

R. Perry,

Unfortunately, and as you probably already know, the FAA placed 100% of drone collision avoidance on the back of drone operators. Manned aircraft are of course required do whatever possible to maintain safe flight, mostly for their own survival, but the FAA has deemed drones as too small for manned aircraft to detect in time to avoid collision.

As for avoiding manned aircraft, especially helicopters and agricultural airplanes, perhaps the only good way to avoid them is to avoid where they commonly fly. I used to fly RC from an ag aircraft runway where the RC folks were expected to clear the runway and airspace when an ag plane approached. That worked ok for the piston engine planes as we could hear them coming. We could not hear a turbine powered ag plane until the tires hit the pavement.

Helicopters present other issues as some of the newer designs are quieter than helicopters of the past. Some Models are extremely difficult to hear until they are almost on top of you, and the lower they fly the closer they can get before you can hear them. It’s the same reason military helicopters and some propeller driven airplanes fly low and fast in combat zones. The aircraft is on top of people before they have a chance to react to them, and gone before weapons can be brought to bear.

 

[clolsonus]

What Pat said. My experience is also that when airplanes/helicopters are 500+ feet high where they normally should be, you can hear them miles away and I always hear them before I see them. My ears are my primary see-and-avoid sensor. But when someone is flying at 100-200' I think the ground and trees and corn suck up all that sound ... at least around these parts where everything is pretty flat and the horizon is never more than a 1/2 mile away due to tree lines (it is totally different out west with terrain and interesting desserts and cool deserts too.) It can lead to a situation (and it's happened to me 2-3 times) where the aircraft bursts out over the tree line and it's right on top of you already when you hear it for the first time.

And then sometimes weird stuff happens. I was flying this past Thursday evening maybe 30-45 minutes before sunset. My aircraft was flying @ 200' AGL holding 25 kts airspeed. Our insect traps were deployed we were just flying a standard grid pattern over a small area of berry fields. Pretty much out of no where a plane that had been well above overflying the area cut his throttle and went into a fairly steep descending turn right over us. I had my transmitter in hand, ready to take over manual flight and evade if needed. I waited to see what he was going to do. He ended up doing more than a 360, probably leveled out around 700-800' right over top of us, powered up the throttle a little bit and then puttered away. I don't know if he saw our airplane (it was well lit with LED strips) and came down to take a look? Or maybe by chance they picked that spot to do some practice maneuver? No idea? They never really got that close vertically, but this all happened right above our area so it definitely got our attention. I forgot to start my nose cam for that flight, so I couldn't check if that saw anything. It was one of those dead calm perfect evenings after a dead calm perfect day, so everyone was out flying around. We even saw two hot air balloons way off on the horizon, but what little wind there was carried them further away from us.

 

[BenMcCormick]

View of my Topsun Strobe Light 5 Cree Led Lights@ 400' AGL

Amazon.com: Topsun Drone Strobe Drone Strobe Light 5 Cree Led Lights For Night Flights Fits All Multirotor Quadcopter UAS DJI Inspire 1 2 Phantom Mavic Pro AIR Typhoon: Toys & Games

Amazon.com: Topsun Drone Strobe Drone Strobe Light 5 Cree Led Lights For Night Flights Fits All Multirotor Quadcopter UAS DJI Inspire 1 2 Phantom Mavic Pro AIR Typhoon: Toys & Games

www.amazon.com

When I placed the strobe light on the landing pad, it was very hard to see. Only against a dark backgound do these lights show up in daylight. At dusk, these are supposed to be seen at 3 to 5 miles out.
One afternoon I was flying when the sky was solid white all around, good visibility. I could look down at the controller and back up again and find the drone no problem. Its just when there are distinct clouds, which is most of the time, is my VLOS fairly close as there is too much going on in the sky to re-acquire the dot. Also, when operating at ground level, it doesn't take much to be at max VLOS with trees and buildings around. I can go further out when standing up higher on my 2nd story porch, then again, its only between ground obstacles that VLOS is possible.
I'm lucky enough to be able to read a few lines below the 20/20 vision which the ophthalmologist says is fairly rare.

 

[R.Perry]

Pat I agree with you that the done pilot carries most of the responsibility, my point was the manned aircraft pilots need to use a little common sense, something that is lacking with some of them. Flying below 500 feet isn't using common sense, altitude is your friend, not pretending your making a strafing run. Even when I was crop dusting, and had a lot less sense than I do today, I didn't fly in transit below 500 feet and if I had any distance to go it was closer to 1000. Why, if something went south, I had more time to react and hopefully not kill myself.

Think, if you are flying at 200 feet and you go dead stick, you are going to land on whatever is in front of you unless you have enough airspeed to pop up and look for a place to land, but by the time you pop up, your air speed it gone, and you are coming right back down. The helicopter guys flying that low are nuts for many of the same reasons.

 

[dronecyclops]

Where did you find that clarification?

Line 2 touch's on this doesn't say orientation though kinda close though

Little Known Facts About Part 107’s “Visual Line of Sight (VLOS)" Rule That You Might Not Be Aware Of

The absence of necessary infrastructure means that FAA has persisted with their line of sight (VLOS) rule. Are there any exceptions to the rule?

www.thedroneu.com

 

[Phaedrus]

Where did you find that clarification?

Part 107.31

§ 107.31 Visual line of sight aircraft operation.

(a) With vision that is unaided by any device other than corrective lenses, the remote pilot in command, the visual observer (if one is used), and the person manipulating the flight control of the small unmanned aircraft system must be able to see the unmanned aircraft throughout the entire flight in order to:

(1) Know the unmanned aircraft’s location;
(2) Determine the unmanned aircraft’s attitude, altitude, and direction of flight;
(3) Observe the airspace for other air traffic or hazards; and
(4) Determine that the unmanned aircraft does not endanger the life or property of another.

(b) Throughout the entire flight of the small unmanned aircraft, the ability described in subsection (a) of this section must be exercised by either:

(1) The remote pilot in command and the person manipulating the flight controls of the small unmanned aircraft system; or
(2) A visual observer.

 

[Earthman]

I mostly fly fixed wing. I have interpreted the line of sight rule as keeping the aircraft close enough where I can visually see the aircraft *and* judge it's orientation well enough to fly it manually (like an RC pilot) and be able to take immediate evasive action if a manned aircraft flies into the area. I can get down below the tree line to safety in like 3 seconds with an airplane.

You are right. You or your observer must be able to see the drone visual line of sight (VLOS) at all times unaided except for prescription glasses. The FAA also says that you as PIC must be able to tell the drone’s orientation and control it as needed, which is difficult if not impossible if it’s a speck in the sky.

Using the video feed and flying FPV isn’t allowed except for a few seconds to frame a shot unless you have an observer.

I also fly fixed wing RC planes and used to have great eyesight, but it’s not so great anymore. Typing on a PC all day is bad for your eyes.