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Why We All Get UAS Night Flight So Unbelievably Wrong

Why We All Get UAS Night Flight So Unbelievably Wrong

As with most things in my aviation world, what began as pulling at a loose thread has resulted in the unraveling of what most people assume about night flight. I’m working on a giant online class with multiple lectures, so I decided to chase the rabbit hole.

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This information will apply to all pilots, especially when night flight is included in the Part 107 certification or recurrence.

This will certainly apply to all COA flight operations.

Here is what people have been told.

To fly at night or in civil twilight, we need to have strobe lights on the aircraft that can be seen for at least 3 statute miles (SM). FAR 107.29

Since the drones flying today are not certified airworthy, no manufacturer can say their strobes meet that requirement. The pilot has to test them. See Did You Know Your Anti-Collision Lights Are Not Compliant?

As part of flying at night, you have to maintain sight of the aircraft at night.

Night Operations 107.29 Waivers

The assumption that many have made, and I will admit, even me, is that if I can see the strobes and read the controller’s telemetry, I would be okay. Spoiler alert: Nope!

But as the FAA pointed out, “The strobes are there so other manned traffic can see the drone in time to react to the drone.” Not for the drone pilot to use to comply with night flight requirements.

I Was Wrong and So Are a Lot of Pilots.

As I began to pull the loose thread, I thought about the recent release of the Tactical Beyond Visual Line of Sight (TBVLOS) waivers that the FAA made a splash about. Under that waiver, the pilot is limited to fly no further than 1,500 from the PIC. See The Most Important Question You Need to Ask About New BVLOS Waivers.

So the question that started rumbling around in my head was if the FAA has defined that TBVLOS is limited to 1,500 feet, then night flight can’t be unlimited as long as you can see the strobes. So what distance is the limit at?

I turned to friends at the FAA and pointed out the lack of anything specific in 107.29 Daytime Waivers and what the waiver trend analysis says.

What resulted was a giant black hole of information where the answer has not been made abundantly clear, but the answer is obvious.

“But Steve, how can it be both?”

The answer lies in FAR 107.31. That’s the section that needed to be waived for BVLOS.

All pilots must still comply with FAR 107.31 and maintain a visual line of sight operation under flight at night. Keep in mind that a COA agency must maintain the same or greater standards for flight operations even they self-regulate. So all UAS pilots flying at night need to comply with VLOS requirements.

So What Are The Real Night Flight Requirements

You don’t need to see the drone flashing, you have to visualize it.

An acronym to remember is LAASDON. Using your eyes you must be able to determine the following information of the drone in flight.

L– location;
A– altitude;
A– attitude;
S– speed;
D– direction of flight;
O– obstacle clearance;
N– not creating a hazard to other aircraft or persons or property on the ground.

Here is another gotcha. While the controller’s telemetry might provide most of that information, you can’t use that to comply with 107.31.

No. You actually have to observe the aircraft and visually confirm this information.

FAR 107.31 says, “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” determine the LAASDON information.

I’ve rummaged this around with some other experienced pilots, and while we all agreed most night fly has not occurred within these rules, we all came up with a similar answer on distance.

Spoiler alert; it’s much less than you think.

Every Situation is Different

All flight operations are different because of terrain, weather, and foliage, but the size of the aircraft makes a huge difference.

You can’t see a small drone such as a Mavic as far as you can see a larger UAS like a Matrice. Size matters.

When push came to shove to give a distance for a Matrice to be flown in clear conditions to be able to confirm the LAASDON information visually, we all felt that it would be in the 1,000-foot range or less range from the PIC at night. That’s not very far. A Mavic would be even less.

And the darker the night, the shorter the distance yet. It doesn’t take long for a drone on a black ink night to vanish from visual sight so you can determine:

L– location;
A– altitude;
A– attitude;
S– speed;
D– direction of flight;
O– obstacle clearance;
N– not creating a hazard to other aircraft or persons or property on the ground.

You Didn’t Expect This Would Not Get Even More Complicated, Did You?

When thinking about seeing the drone at night, many factors can influence vision. The strobe lights can reduce your night adaptation, night visual acuity measurements are more like Functional Visual Acuity (FVA) than standard visual acuity. Ocular conditions like Lasix surgery or early cataracts can reduce the pilot’s night vision. Situational issues like light pollution will restrict your ability as well.

The actual distance you can visually see the drone and know its LAASDON without looking at the controller will be different for each pilot.

All people have a reduction of their FVA at night. For example, one source states, “Functional visual acuity of normally 20/20 patient decreases to 20/40 when driving at night- time, going >55MPH, with high beams on.” On a busy incident scene with flashing lights and strobes going off, your FVA is going to be even less.

Do What You Want at Your Own Risk

I’m just putting this information out there, and each pilot must make their own determination on how badly they are going to break a FAR. Any pilot who violates a FAR is personally liable when the aircraft crashes, flies away or damages property. And the rule I live by as a pilot is nobody ever has an emergency or crashes until they do.

Before I had this inflight emergency as Compassion 431 I felt invincible and that was in a certified aircraft. I no longer feel invincible. The drones we fly are uncertified aircraft with no safety standards to comply with.

After pointing out all these issues in discussions with the FAA, the response I got was that anyone conducting night flights beyond those visual 107.31 requirements should “take a hard look in the mirror and consider changing your aviation safety culture if you even remotely think that’s a good risk to take.”

And the response raised a very good point about the 107.29 waivers, not mentioning any of these issues, “The reason it doesn’t reference 107.31 is that a 107.29 waiver is only to fly at night, and the applicant didn’t ask for relief on 107.31.”

That’s true.

About Steve Rhode

Steve is an experienced and certificated UAS pilot and aircraft instrument-rated pilot. He is also the Chief Pilot with the Wake Forest Fire Department and North Carolina Public Safety Drone Academy. He is also a member of the FAA Safety Team.

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