Line of Sight Friend or Foe?

[Mark Brimblecombe]

It says visual line of sight. It doesn't say in sight. There is actually a difference. Notice how vague they make that law.

In the rules of the Civil Aviation Authority here in New Zealand it says “Maintain visual line of sight with the aircraft.” It also says that this is “a straight line along which an observer has a clear view”. It does not say that the aircraft/drone itself must be visible to the remote pilot. The point of this law is that one must be able to see where the drone is in the airspace without any obstruction between, and have a clear and unobstructed view of the surrounding airspace for seeing any other aircraft in the vicinity. As the law says “a straight line along which an observer has a clear view.”

 

[Just_nick]

I feel I should point out that US Federal Aviation Administration Regulations are NOT laws and the sanctions for not adhering to them are vague at best and the "enforcement" of most of them, especially the VLOS is all but impossible without an accident or complaint to trigger a costly investigation..

"Line of sight" does not mean to me that I must be able to 'see' my aircraft at all times, although I doubt the FAA minds very much if you misinterpret their rule.

So long as I know the general location of my AC (which is best determined by the camera shot and not by the naked eye beyond a few hundred feet) and I am able to monitor the area for other traffic, I contend that I am in compliance. I think the rule is primarily intended to prevent loss of that invisible control signal which does depend on a direct and unobstructed 'view".

If I kept my drone always within my sight, flying it would be of no use whatever. This regulation will not stand the test of time for it constitutes an obstruction to the intended use of the UAV.

The collision with the heli was no doubt caused by ignoring a no-fly zone situation and not by any loss of sight of the drone. It could just as easily have happened as the pilot watched.

Not understanding the meaning of a word does not mean it's vague, it just means you need to have someone explain the words to you.

 

[wytnyt]

You might want to read about the Phantom 4 which had a mid air collision with an Army helicopter near Coney Island while out of sight of operator. Could be costly for operator of the Phantom. All issues aren't attached to the ground as buildings, trees, etc. Luckily, it did minor damage to the helicopter, though it did bring back pieces of the drone. Damage to heli rotor could be costly. I don't know how they tracked it back to owner. He just knew his Phantom lost contact and did not return home. He had no idea he had had a collision till the FAA knocked on his door.

Line of site. It's not just a law, it's a good idea.

i read they tracked it by finding one of the motors serial #

 

[Callum]

“Maintain visual line of sight with the aircraft.” It also says that this is “a straight line along which an observer has a clear view”. It does not say that the aircraft/drone itself must be visible to the remote pilot.

Surely the key word there is "visual".

You can't have VLOS if you can't see the aircraft.

VLOS means you can see the aircraft with unaided eye.

 

[Mark Brimblecombe]

Surely the key word there is "visual".

You can't have VLOS if you can't see the aircraft.

VLOS means you can see the aircraft with unaided eye.

Not according to the law in our part of the world, where it defines VLOS as
“a straight line along which an observer has a clear view” which is both unobstructed and enables a view of the surrounding airspace.

 

[Mark Brimblecombe]

Not according to the law in our part of the world, where it defines VLOS as
“a straight line along which an observer has a clear view” which is both unobstructed and enables a view of the surrounding airspace.

This is I guess the reason why there is no mention in the NZ rules, or official interpretations of those rules, that VLOS means being able to actually see the aircraft/drone being flown. But of course you need to know exactly where it is to know the 'straight line' between you and the drone.

 

[787steve]

Mark,
You sent me googling with that one. I could not figure why they would use the term VISUAL Line of Sight, if it just meant Line of Sight.

I found this link to the NZ CAA Advisory Circular which you might want to check out:
https://www.caa.govt.nz/Advisory_Circulars/AC101-1.pdf

I had to go on a similar search to find the US version of the same thing. They don't make it easy to find all you need to know.

From the NZ Advisor4y Cirular: 101.209 Visual line-of-sight operation This rule outlines requirements for an operator to ensure their operation remains within unaided visual sight (i.e. without the use of an instrument, such as binoculars or a telescope). First-person view systems are permitted under this rule, but still require a separate observer, who has suitable training and competency, and can maintain unaided visual line of sight contact at all times, with the aircraft and have direct communication with the pilot. This observer is, among other things, to advise the pilot of any other traffic that enters the operational area, the direction it is coming from, and advice on the appropriate actions to take to maintain safe clearances.

Bold print is mine.

Fly Safe

 

[kcabpilot]

I’ve been a pilot for 47 years and I’m pretty good at spotting other airplanes in the sky and although they travel much faster they are also much bigger and outside of military virtually no aircraft are painted dark gray. The Mavic is tiny and dark and it doesn’t take very long at all for it to disappear even with LED’s on. At first I freaked out every time I lost sight of it but got used to using the screen and map. So, for the time being my story is yea, it’s in visual line of sight but I just temporarily lost it and I’m workin’ on it! Or better yet, I had it in sight until you asked and distracted me. Now I can’t find it, thanks a lot.

 

[Callum]

Not according to the law in our part of the world, where it defines VLOS as
“a straight line along which an observer has a clear view” which is both unobstructed and enables a view of the surrounding airspace.

Are you sure about that?

Usually aviation terms and acronyms mean the same thing in any country.

ICAO (which NZ are a member) define VLOS ops as,

Visual line-of-sight (VLOS) operation. An operation in which the remote pilot or RPA observer
maintains direct unaided visual contact with the remotely piloted aircraft.

 

[kcabpilot]

How about shading your eyes from the sun with a ball cap, would that be considered “aided”? Believe me, when it comes to FAR’s you don’t want to read too deep into it. I am thinking of skinning my Mavic with some florescent decals though because it is darn hard to see.

 

[Mark Brimblecombe]

Mark,
You sent me googling with that one. I could not figure why they would use the term VISUAL Line of Sight, if it just meant Line of Sight.

I found this link to the NZ CAA Advisory Circular which you might want to check out:
https://www.caa.govt.nz/Advisory_Circulars/AC101-1.pdf

I had to go on a similar search to find the US version of the same thing. They don't make it easy to find all you need to know.

From the NZ Advisor4y Cirular: 101.209 Visual line-of-sight operation This rule outlines requirements for an operator to ensure their operation remains within unaided visual sight (i.e. without the use of an instrument, such as binoculars or a telescope). First-person view systems are permitted under this rule, but still require a separate observer, who has suitable training and competency, and can maintain unaided visual line of sight contact at all times, with the aircraft and have direct communication with the pilot. This observer is, among other things, to advise the pilot of any other traffic that enters the operational area, the direction it is coming from, and advice on the appropriate actions to take to maintain safe clearances.

Bold print is mine.

Fly Safe

Thanks for this reference to the New Zealand CAA Circular which predates the current law by about 18 months. It does interpret the law at the time in 2015 as VLOS meaning visual "contact at all times, with the aircraft..." It is strange, and perhaps intentionally ambiguous, that this is left out of the Part 101 CAA Consolidation document of 10 March 2017.

You are certainly right about the authorities not making this easy "to find out all you need to know."

 

[Callum]

Thanks for this reference to the New Zealand CAA Circular which predates the current law by about 18 months. It does interpret the law at the time in 2015 as VLOS meaning visual "contact at all times, with the aircraft..." It is strange, and perhaps intentionally ambiguous, that this is left out of the Part 101 CAA Consolidation document of 10 March 2017.

You are certainly right about the authorities not making this easy "to find out all you need to know."

Curiosity got the better of me.

Your right it is poorly written. They are assuming people will understand the term "visual" means you can see the aircraft.

If you look at (C)(1) they state you must maintain visual line of sight of the aircraft.

(C)(2) They state you must also be able to see the surrounding airspace.

This is 2 separate instructions.

First one is for you to have eyes on aircraft at all times.

Second is a bit vague as if you can see the aircraft you can also see the airspace right?
I think it's meant to stop you flying at the side of a tall structure. You can see the aircraft and airspace to left but the structure blocks your view of the airspace to the right.


101.209 Visual line of sight operation
(a) This rule applies to the following types of aircraft:
(1) a remotely piloted aircraft:
(2) a free flight model aircraft.
(b) A person must not operate an aircraft to which this rule applies in—
(1) any area in which the person’s view of the surrounding airspace
in which the aircraft will operate is obstructed; or
(2) meteorological conditions that obstruct the person’s ability to
maintain visual line of sight of the aircraft.
(c) A person who operates an aircraft to which this rule applies must at all times ----

(1) maintain visual line of sight with the aircraft; and
(2) be able to see the surrounding airspace in which the aircraft is
operating; and
(3) operate the aircraft below the cloud base.
(d) For the purposes of this rule visual line of sight means a straight line
along which an observer has a clear view and which may be achieved with
the use of—
(1) spectacles, contact lenses, or a similar device used to correct
subnormal vision of the user to no better than normal vision but
not the use of an electronic, mechanical, electromagnetic,
optical, or electro-optical instrument; or
(2) a first person view system and a trained and competent observer
who maintains—
(i) visual line of sight of the aircraft; and
(ii) sight of the surrounding airspace in which the aircraft is
operating; and
(iii) direct communication with the person who is operating
the aircraft.

 

[Fl_FLyer]

The rules do not say "in visual sight" but in VLOS, meaning there are no obstructions between you and the drone, so that you can see the area around the drone. That way if a manned vehicle enters the area near your drone, you can take action such as reducing the altitude of the drone.

 

[Callum]

The rules do not say "in visual sight" but in VLOS, meaning there are no obstructions between you and the drone, so that you can see the area around the drone. That way if a manned vehicle enters the area near your drone, you can take action such as reducing the altitude of the drone.

VLOS (visual line of sight) means direct unaided visual contact with the aircraft.

That means you need to see the aircraft, not the airspace around it.

 

[Robert Mitchell]

VLOS (visual line of sight) means direct unaided visual contact with the aircraft.

That means you need to see the aircraft, not the airspace around it.

Even if you’re absolutely correct - and I’m not saying you’re not - trying to convince most people at this point is like trying to get them to stop using their cellphones while driving. Just ain’t gonna happen.

 

[Mark Brimblecombe]

VLOS (visual line of sight) means direct unaided visual contact with the aircraft.

That means you need to see the aircraft, not the airspace around it.

Thanks Callum for your comments. I think you're right. Another reason I can think of for always being able to see the drone is in the event of a loss of signal, GPS, or even the flying app crashing on your phone/tablet/monitor. You need to be able to manually fly the drone home or manually fly to avoid 'obstacles' in the vicinity, and not depend on 'return to home' automation. I think this is all the more important when drone 'haters' are now using signal jammers too. Two of my friends this week have had their expensive FPV racing drones just fall out of the sky because someone in the vicinity was using one of these devices.

 

[Callum]

Even if you’re absolutely correct - and I’m not saying you’re not - trying to convince most people at this point is like trying to get them to stop using their cellphones while driving. Just ain’t gonna happen.

Yeah, everyone does their own thing. I don't always stick to the rules. I know I am sometimes breaking them but do it where minimal risk and it's on my head.

Not trying to preach rules or regulations to anyone. Couldn't care less what people do.

Just getting point across that VLOS means you can see the aircraft. Anyone who has flown RC will know this has always been the case.

ICAO who set aviation standards across the globe have adopted VLOS in their UAS policy and defined it as in unaided sight.

 

[787steve]

Come to think of it, if you can't see the drone, how do you really know that you are looking in the right place to see the area around the drone? I am noob, but so far always try to fly VLOS. But I have lost sight on occasion and reacquired it in an area away fro where I expected it to be.
What a mess! They could just spell it out clearly. NO, that would be too easy.

 

[Mossiback]

Come to think of it, if you can't see the drone, how do you really know that you are looking in the right place to see the area around the drone?...

I also try to keep it in VLOS but have lost track of that little dark speck. When it happens, I use the video display to look back at myself and then pick up landmarks to sight back to the Mavic. When I am sure I am looking at the right part of the sky I bounce it up/down, left/right until I see it again. If that doesn't work I just bring it back until I see it.

 

[Fl_FLyer]

VLOS (visual line of sight) means direct unaided visual contact with the aircraft.

That means you need to see the aircraft, not the airspace around it.

I never said "not see the aircraft". You need to be able to see both, the aircraft and the airspace around it. It is called situational awareness. To focus just on the sUAV and not pay attention to the airspace around it is dangerous.