Question about FAA Advisory Circular AC91-57C regarding VLOS

[Dangerly]

In order to be operating within visual line of sight (VLOS), either the operator or a visual observer (VO) must be able to see the UA (with vision unaided by any device other than corrective lenses) throughout the entire flight to ensure it does not present a collision hazard to other manned aircraft or persons or property on the ground.
Source: Page 7, 2.2.3.1, faa.gov/documentLibrary/media/Advisory_Circular/AC_91-57C_FAA_Revised.pdf

Question: The wording says you must "be able to see the UA" and it doesn't say you must continuously see the UA. Is this ambiguous? Being "able to see" means you could look away for periods of time, such as looking at your RC, so long as you could look up and see the UA if you wanted to. Am I understanding this correctly? Or must you continuously have eyes directly on the drone without looking away, in which case, how could you ever look at your RC?

If you can look away, is there guidance on for how long you can look away? For how much of your flight could you be looking at your RC and not the drone, so long as you are still "able to see" the drone if you wanted to? Could you fly the whole flight looking at your RC, so long as you are "able to see" the drone if you want to?

 

[GFields]

Am I understanding this correctly?

Yes

If you can look away, is there guidance on for how long you can look away?

A precise amount of time is not stated but I'm sure it is meant to be within reason.

Could you fly the whole flight looking at your RC, so long as you are "able to see" the drone if you want to?

No

 

[msinger]

Being "able to see" means you could look away for periods of time

If you've looked away, you're no longer able to see the aircraft with your eyes.

When flying any type of aircraft (manned or not), you sometimes have to look away to see the controls, screens, etc. However, the majority of your flight should be spent with eyes on the aircraft to "ensure it does not present a collision hazard to other manned aircraft or persons or property on the ground".

 

[Dangerly]

If you've looked away, you're no longer able to see the aircraft with your eyes.

That's certainly one interpretation, and I think that means you could never look at your RC. Is that what you're saying?

Is your interpretation different from what @GFields wrote before you, who wrote with regard to the amount of time you could look away "I'm sure it is meant to be within reason"?

 

[msinger]

That's certainly one interpretation, and I think that means you could never look at your RC. Is that what you're saying?

No. I'm saying the FAA is probably well aware that it would be unreasonable for them to ask pilots to look at their drone 100% of the time.

Like driving a car, it's impossible to look at the road 100% of the time. However, you're looking at the road most of the time.

 

[Dangerly]

No. I'm saying the FAA is probably well aware that it would be unreasonable for them to ask pilots to look at their drone 100% of the time.

Like driving a car, it's impossible to look at the road 100% of the time. However, you're looking at the road most of the time.

That's a good comparison. When driving a car I don't take my eyes of the road for more than a second or two. What do you think a good rule of thumb would be for a drone, in terms of how long you could safely look away?

 

[brett8883]

If you can look away, is there guidance on for how long you can look away? For how much of your flight could you be looking at your RC and not the drone, so long as you are still "able to see" the drone if you wanted to?

It’s purposeful vague. You only have to look at it enough so that you can fulfill your other obligations such as flying in a safe manner and giving way to manned aircraft. If flying out in the boonies with no property, people, or manned aircraft around you then you probably don’t need to look at very much. If flying in the city or in controlled airspace you will need to look at it more often. It’s a best judgement thing.

Of significant note is that “either the operator or a visual observer (VO) must be able to see the UA.” Meaning if you have a VO you can look away for extended periods or in the case of FPV not at all.

Could you fly the whole flight looking at your RC, so long as you are "able to see" the drone if you want to?

If you have a visual observer then easily, yes. However, it would be very difficult to make the argument that you are able to ensure safe operation and give way to manned aircraft if you don’t ever look up from your RC without a VO.

It’s not so much “if you want to” it’s “if you are able to fly safely and avoid manned aircraft.

The CBO you join may have additional rules and guidelines on this topic.

 

[brett8883]

EDIT: I have to confess that I thought this was the part 107 AC and now realizing it’s the recreational pilots AC so I have edited my remarks above to tailor them to recreational pilots. Same overall point but less leeway for pilot judgment. There’s really no conceivable situation where a solo recreational pilot could get away with not looking at the aircraft at all during flight unless they have a VO.

 

[GFields]

If you have a visual observer then easily, yes.

No. According to the FAA, the PIC, as well as the VO must be able to see the UAV at all times. That is not saying see continuously but should be able to see it at any given time.

§ 107.33 Visual observer.​

If a visual observer is used during the aircraft operation, all of the following requirements must be met:

(a) The remote pilot in command, the person manipulating the flight controls of the small unmanned aircraft system, and the visual observer must maintain effective communication with each other at all times.

(b) The remote pilot in command must ensure that the visual observer is able to see the unmanned aircraft in the manner specified in § 107.31.

(c) The remote pilot in command, the person manipulating the flight controls of the small unmanned aircraft system, and the visual observer must coordinate to do the following:
(1) Scan the airspace where the small unmanned aircraft is operating for any potential collision hazard; and
(2) Maintain awareness of the position of the small unmanned aircraft through direct visual observation.

 

[msinger]

According to the FAA, the PIC, as well as the VO must be able to see the UAV at all times

(c) above states the following:

"The remote pilot in command, the person manipulating the flight controls of the small unmanned aircraft system, and the visual observer must coordinate" to "maintain awareness of the position of the small unmanned aircraft through direct visual observation"

Where does it state both the PIC and VO must be able to see the UAV at all times?

 

[brett8883]

No. According to the FAA, the PIC, as well as the VO must be able to see the UAV at all times. That is not saying see continuously but should be able to see it at any given time.

§ 107.33 Visual observer.​

If a visual observer is used during the aircraft operation, all of the following requirements must be met:

(a) The remote pilot in command, the person manipulating the flight controls of the small unmanned aircraft system, and the visual observer must maintain effective communication with each other at all times.

(b) The remote pilot in command must ensure that the visual observer is able to see the unmanned aircraft in the manner specified in § 107.31.

(c) The remote pilot in command, the person manipulating the flight controls of the small unmanned aircraft system, and the visual observer must coordinate to do the following:
(1) Scan the airspace where the small unmanned aircraft is operating for any potential collision hazard; and
(2) Maintain awareness of the position of the small unmanned aircraft through direct visual observation.

First of all this thread is about recreational rules not part 107, don’t worry I made the same mistake. Recreational rules are more straight forward.

In part 107 rules the thing you have to keep in mind is the rules are meant to read as a whole. You can’t just take one section out. The preceding rule to the one you quoted says:

“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 paragraph (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.”


Part 107.33, which you quoted, basically just lays out that since the VO is taking the VLOS responsibility the PIC and person operating the controls has to make sure the drone stays within the VO’s VLOS and through coordination and communication

EDITED for length and clarity

 

[brett8883]

Recreational Rules are more straight forward. They say:
Section 44809(a)(3). “The aircraft is flown within the visual line of sight of the person operating the aircraft or a visual observer co-located and in direct communication with the operator.”

2.2.3.1 In order to be operating within visual line of sight (VLOS), either the operator or a visual observer (VO) must be able to see the UA (with vision unaided by any device other than corrective lenses) throughout the entire flight to ensure it does not present a collision hazard to other manned aircraft or persons or property on the ground. The use of a VO is optional, but a VO enables the recreational flyer to look away from the UA for extended periods. The use of a VO is necessary if the recreational flyer wants to use first person view (FPV) devices, which allow a view from an onboard camera but limit the operator’s ability to scan the surrounding airspace.

 

[thispilothere]

No. According to the FAA, the PIC, as well as the VO must be able to see the UAV at all times. That is not saying see continuously but should be able to see it at any given time.

If that were true, it would be impossible to fly FPV drones legally.

 

[GFields]

(c) above states the following:

"The remote pilot in command, the person manipulating the flight controls of the small unmanned aircraft system, and the visual observer must coordinate" to "maintain awareness of the position of the small unmanned aircraft through direct visual observation"

Where does it state both the PIC and VO must be able to see the UAV at all times?

(2) Maintain awareness of the position of the small unmanned aircraft through direct visual observation.

 

[msinger]

(2) Maintain awareness of the position of the small unmanned aircraft through direct visual observation.

Right. And then if you put everything together, it's stating either the PIC or VO must maintain awareness of the position of the small unmanned aircraft through direct visual observation.

 

[GFields]

I failed to realize the original question was concerning 44809: Exception Pilots. Please note that my replies deal with Part 107 pilots. With that said, let's get back to the original post.

 

[msinger]

Please note that my replies deal with Part 107 pilots

No worries. In that respect, the rules are identical in both cases.

 

[GFields]

Right. And then if you put everything together, it's stating either the PIC or VO must maintain awareness of the position of the small unmanned aircraft through direct visual observation.

(c) The remote pilot in command, the person manipulating the flight controls of the small unmanned aircraft system, and the visual observer must coordinate to do the following:
(1) Scan the airspace where the small unmanned aircraft is operating for any potential collision hazard; and
(2) Maintain awareness of the position of the small unmanned aircraft through direct visual observation.
If my interpretation of Section C is incorrect, I accept that. Maintaining awareness could mean either "to see" or "communicate." the location of the drone
Could be argued to include both the PIC and VO. However, since this does not pertain to the OP's question. Further discussion may only cause more confusion.

 

[RPerry]

Question: The wording says you must "be able to see the UA" and it doesn't say you must continuously see the UA. Is this ambiguous? Being "able to see" means you could look away for periods of time, such as looking at your RC, so long as you could look up and see the UA if you wanted to. Am I understanding this correctly? Or must you continuously have eyes directly on the drone without looking away, in which case, how could you ever look at your RC?

If you can look away, is there guidance on for how long you can look away? For how much of your flight could you be looking at your RC and not the drone, so long as you are still "able to see" the drone if you wanted to? Could you fly the whole flight looking at your RC, so long as you are "able to see" the drone if you want to?

You have a good question. For me, I watch the display most of the time, it tells me more about what the drone is doing more than me staring at the drone. I have done a lot of large acreage mapping where the drone at times was almost a half a mile away. I could still see it, but it was a speck in the sky. Those flights were autonomous so I wasn't flying the drone, the mapping software was. By close monitoring of the tablet I could not only keep an eye on battery and flight conditions but also picture quality and tracking accuracy. I'm an ex-pilot, I learned to live by my instruments so watching the tablet just comes naturally to me.

 

[brett8883]

(c) The remote pilot in command, the person manipulating the flight controls of the small unmanned aircraft system, and the visual observer must coordinate to do the following:
(1) Scan the airspace where the small unmanned aircraft is operating for any potential collision hazard; and
(2) Maintain awareness of the position of the small unmanned aircraft through direct visual observation.
If my interpretation of Section C is incorrect, I accept that. Maintaining awareness could mean either "to see" or "communicate." the location of the drone
Could be argued to include both the PIC and VO. However, since this does not pertain to the OP's question. Further discussion may only cause more confusion.

Prefacing this by saying the following only pertains to Part 107 rules not to recreational flyers so as to not cause anyone confusion.

This section has to be taken as a whole and in conjunction with part 107.31. In part 107.31 it establishes that either the PIC/person manipulating the controls or a visual observer has to be watching the aircraft.

When the PIC/person manipulating the controls is the one doing the observing it doesn’t matter if the VO can see the aircraft or not. PIC/PMC is in control of the aircraft so he/she is able to maneuver it so that they keep it within VLOS without needing input from the VO. The VO can help but it’s not a requirement that they be able to see it in this case.

107.33 deals with the situation where the PIC/PMC is not doing the observing and is relying on the VO for the visual awareness. There are 3 requirements to make this situation work. (Below is my commentary on what the rule means not the rule itself)

1. Both parties must maintain effective communication. Unlike the recreational rule there’s no requirement that the VO be co-located so communication is key. Use of radios etc. 107.33 (a)

2. The PIC/PMC must keep the aircraft within the VO’s visual line of sight. The VO isn’t in control of the aircraft so it’s the PIC job to make sure the aircraft stays within the VO’s sight. 107.33 (b)

3. Even if the VO is in charge of watching the drone for the PIC/PMC, there still needs to be awareness of incoming manned aircraft. This is kinda a separate issue to watching the drone so you could see where the PIC thinks the VO is watching for manned aircraft but they were just told to watch the drone so it doesn’t get done. The PIC could also do this without having to watch the drone. Whatever the case, somebody needs to do this so coordination is required by all parties to make sure this happens one way or the other. 107.33 (c)