Digital Flight Rules (DFR) keeps popping up in drone talk because it goes straight at the one safety question we still cannot answer cleanly: Who separates traffic in the “drone band”?
DFR is being pitched as a third operating concept alongside VFR and IFR, something that could apply across the NAS. The problem is not up high where aircraft are usually visible to the system and traffic is more predictable. The problem is down low, surface to 400 feet AGL, where most small drones live and where a lot of real work gets done.
That band is not empty. Helicopters, agricultural aircraft, pipeline and power patrol, firefighting, law enforcement, and EMS work down there, close to terrain and wires, often in a hurry.
VFR separation is mostly see-and-avoid. We borrow help when we can: flight following, traffic advisories, ADS-B Out and In, and sometimes TCAS cues. Helpful, but it does not guarantee separation for VFR the way the system is designed to do for IFR. It lowers risk. It does not own it.
IFR works because responsibility is clear. You file, you comply, and ATC provides separation using procedures, surveillance, and controller tools. Somebody is in charge of keeping airplanes apart.
Now look at what is happening in the drone band. The number of units is climbing, and the weight is climbing, too. That is risk bloat. More units means more density. More weight means more energy on impact. Both matter to every low-level pilot and crew.
The FAA’s own forecast puts the U.S. at about 1.93 million recreational small drones and about 1.18 million commercial small drones by 2029. Call it roughly 3.1 million registered sUAS headed into 2030. Micro drones under 0.55 pounds add more volume, registered or not.
The FAA has also made it easier to get permission to be in the airspace. LAANC (Low Altitude Authorization and Notification Capability) automates drone airspace authorizations near airports in controlled airspace, usually at or below 400 feet AGL. Good. But authorization is not separation. It lets you be there, not kept clear of a helicopter on a highway, an ag turn back into a field, or an EMS ship dropping into a scene.
That leads to the next FAA answer, UTM (UAS Traffic Management). UTM is the FAA saying low-altitude drone ops need a cooperative traffic management layer that does not rely on ATC to separate everything. Operators and service providers share information, coordinate, and manage operations so the system can handle volume without ATC for every move.
That is the same low-altitude separation problem DFR is trying to solve.
DFR gets called “Digital Flight Rules.” Here’s what it really means.
DFR is separation by data. Share location and intent, follow the rules, stay clear.
RTCA (Radio Technical Commission for Aeronautics) has been blunt about the concept: Digital Flight is meant to complement VFR and IFR, and DFR would be the regulations that make it real.
RTCA is also blunt about the timeline. The DFR concept is alive, but the implementation is years out. So for now it’s a program for the future. It takes standards, certification, and rulemaking.
Where does BNATCS fit into this? It modernizes the ATC backbone, the part of the NAS where ATC owns separation. If BNATCS delivers reliability and capacity, that helps IFR and controlled operations. But BNATCS is not DFR. DFR needs interoperable digital services and data exchange that work at scale in the low-altitude world, where ATC is not the separation engine.
Then comes the make or break question for the people who actually fly the “drone band.” If DFR ends up expecting manned aircraft to add equipment to “fit in” with digital self-separation, who pays for that?
RTCA’s stated principle is the right one: Digital Flight should not impose new requirements on operations conducted under VFR or IFR. But I do not trust the real-world drift. After a close call, the first question will be, “Why didn’t the pilot see it?” The quickest bureaucratic fix is often a box in the cockpit, even if the burden should stay on the drone side.
If costs get pushed onto helicopters, ag, and working GA, DFR becomes another unfunded mandate aimed downhill.
The bottom line is simple. We can argue LAANC, waivers, Remote ID, DroneZone, and UTM all day. But until we can answer separation cleanly in the drone band, we are building density and impact energy faster than we are building separation.
Amen.
Separation is about safety of flight, safety of flight is about protecting human life, not corporate convenience. Unless the owner/operator of a drone is sitting with a weapon pointed at their head that fires if there is a collision with manned acft, they have no skin in the game and deserve no priority.
The entities pushing for drone rules are the ones most capable of paying for additional infrastructure…paying for lobbyists doesn’t count. Unfortunately what I expect in the near term is those same players gaming the system with notam’d “drone circles” that satisfy requirements without any thought on how the resulting swiss cheese airspace can be avoided by manned acft.
DFR may be a doable concept if everyone plays along. But it doesn’t in the least, address the root cause of drone incursions, which is…operator conduct.
There have been hundreds of sUAS violations in my region within the last two years including nineteen just over this past weekend. All of them are recreational operators. Most of these violations result in a counseling and education session with the occasional penalty thrown in there but the latter is hard to prove even when intentional recklessness is obvious.
Let’s face it and call it what it is, sUAS that are not operating commercially are toys, plain and simple. A gadget that has become so inexpensive, that a child who saves his lunch money for two weeks can buy it off the shelf and have to wait no longer than the time it takes to charge the battery, to operate it in any air space they want to.
So until Congress gets serious about enacting some sort of laws and regulations in the commerce arena, such as specific point of sale requirements for the purchaser, DFR is nothing more than a very very weak attempt at risk mitigation and doesn’t even touch the fringes of risk elimination.
I met an interesting fellow back in the early 90s called Keith Peshak. I call him “interesting” because he came across to me as brilliant, potentially genius, but he had an personality that did not lend himself well to many. But he was usually right.
Anyway, back before ADS-B and glass cockpits and GPS navigation (and certainly before moving maps) and when ATC was really getting overwhelmed and we were wondering where and when and how it was all coming to a head, Keith came up with, and damn well fully developed, a concept he called “Tallights”.
“Tallights” extended the basic “see and avoid” electronically, to include GPS positioning broadcasting. Instead of active separation by ATC management we would all transmit who we are, where we are, and where we were going and we would “see and avoid” among ourselves. And onboard computers would assist in those calculations and movign maps would show us each other.
You know, a lot like we do with our eyes in VFR. But a lot faster (no latency talking with ATC), decisive (no waiting for ATC to make a conflict decision and vector), over a longer distances, and even IFR. Like how we “see and avoid” when driving our cars at night…taillights.
IMO, it was a brilliant (for the time) and workable concept that was quite viable in the early 90s with the upcoming GPS and the proposed ADS-B along with incredible advances in personal PCs and screens. I seem to recall Keith even did a presentation on it at OSH near the mid-90s.
And technology moved on. We do have TCAS in commercial aviation but the costs associated with those overly-complex systems are well out of reach of general aviation, and assuredly so for recreational UAVs.
So…we in GA still rely on ATC for traffic resolution, certainly in IFR and many times even in VFR.
What happened with Taillights? Dunno, I lost track of Keith. I suspect that because his concept were based on future inexpensive retail products not certified by the FAA (and probably never would be) that the FAA would have not been interested in pursuing the concepts. And no avionics manufacturer ever caught on to the idea. And Keith’s vociferous and vocal (and, usually, accurate) criticism of the FAA (and the avionics industry to a degree) did not endear himself to audiences to consider it.
I lost touch with Keith (and another brilliant electrical engineer, Bob Nuckolls) some decades ago but I’ll wager the ideas are still out there…after all, nothing is lost on the Internet. Maybe it’s time to dig those up again…
“Nothing is ever lost on the Internet”
Taillight Specifications:
https://web.archive.org/web/20060514084617/http://www.gtwn.net/~keith.peshak/taillight_specifications.htm
Main page:
https://www.gtwn.net/~keith.peshak/peshak.htm
Wow! Greg, that’s gold. “Taillights” is basically the early skeleton of what DFR is trying to become: cooperative separation by shared data, without turning ATC into a babysitter for everything that moves.
And the alarming part is, the low-altitude mix is getting denser and heavier, fast. Your links are a reminder this problem has been sitting on the ramp for decades, and now the drone volume is pushing it onto the runway. Thanks.
Please define BNATCS.
https://www.faa.gov/newsroom/brand-new-air-traffic-control-system-bnatcs-fact-sheet
Common sense (if that exists!) would point out that another electronic box in the cockpit is NOT the answer. At 400 ft AGL and below, unless on an instrument approach in low IFR to a very low minimum, the pilot MUST be head-up and eyes outside–not watching something on the panel to try to avoid a drone.
When, not if, an electronic or automated method of avoidance is selected as the best choice, the burden must be on the “shoulders” of the drone.
Drones already must detect so many different obstacles, adding staying out of the path of an aircraft must be a top priority–not the other way round.
I sure hope Part 103 operations don’t get lost in this conversation. What expensive box will I have to add to my ultralight, and will there be a box that works even if I don’t have an electrical system? If ultralights aren’t (eventually) required to have a box, what technology in drones will sense and avoid my ultralight?
And there it is: the easiest solution for Part 103 is to restrict the airspace in which they are allowed to fly. A little bubble here, a narrow corridor there, and -poof- “Problem Solved”.
Lets be frank about this. Drones are a threat to pilots everywhere. Our VFR airspace separation is based on “See and avoid”. It is hard to see other aircraft which are larger than an automobile. How on earth are we supposed to see and avid a drone which is smaller than a basketball? Face it that’s is such a low probability that is is essentially impossible. For the FAA to allow these drones to occupy the same airspace as manned aircraft is to put lives in danger. By not planning for separation, they are planning for a collision to take place. It seems they just don’t care. I wonder what the reaction will be when the first pilot or passenger is killed by a drone. It will happen. It is just a matter of time.
Raf,
Good analysis. All of your concerns about EMS, crop dusting, line inspection, etc., are spot on, except that the real end-game is to eliminate humans doing these functions and to turn the piloting over to drones (yes, even EMS) that are all talking to and avoiding each other. That’s why there does not seem to be a lot of concern about people in the 400′ and below space. Even with that, I think the real “regulation” will come from insurance companies responding/reacting to the inevitable personal injury lawsuits resulting from drones striking peopled aircraft. All written in blood…
Steve, all good points. Autonomy may be the end game, but the safety bill comes due in the transition, and that transition is already underway. I also agree insurance will drive “real regulation” fast.
Just when I learned all the VFR cloud clearances they drop this one me.
This is not a new problem.
Asimov identified the issue in his “Three Laws of Robotics” in the middle of WW2:
1) A robot may not injure a human being or allow a human to come to harm
2) A robot must obey the orders given to it by humans, except where such orders conflict with the First Law
3) A robot must protect its own existence as long as it does not conflict with the First or Second Law.
Replace “robot” with “unmanned aerial vehicle” and the solution is stunningly obvious: the UAV (and its human operator, if any) is solely responsible for the safety of every human it encounters in the National Airspace System.
Unless and until a UAV can demonstrate consistent mastery of the “Three Laws of UAVs”, they cannot share the NAS.
QED.
If a human controlled drone encounters another human (airborne or otherwise) it becomes a human vs human encounter. I recall someone once wrote that we’re all equal, but some are more equal than others.
Except that one of those humans has effected an “action at a distance” on the other, akin to someone safely on the ground firing a rifle into the air. The bullet/drone was the proximate cause of death, but good luck finding the human who pulled the trigger.
For your specious assertion to apply, the drone operator must be riding his drone aloft.
The onus remains on the drone to “sense and avoid” human-carrying aircraft, regardless the instructions from its operator.
Until drones have at least the level of “sense&avoid” intelligence found in your average turkey buzzard, they should not be allowed in the NAS.
If I had my way, they wouldn’t be allowed until they acquired a level of sentience to appreciate their own mortality. Until then, they are merely very large caliber bullets.
Mark Schaible raised the right question. Part 103s should not be forced into a pricey cockpit box or shoved into a bubble. The only scalable answer is to burden the side with the volume: drones.
Make every drone, mini or not, follow one hard rule: if it detects an aircraft signal, it gets out of the way. No exceptions. Use ADS-B Out as the trigger, and do not change one screw on any manned aircraft.
For ultralights, hang gliders, and the rest of the low-and-slow crowd, the FAA should offer a cheap, battery “be seen” beacon that drones can receive. Then the drone does the work: slow, descend, turn away, or land if needed.
If it’s secure and can’t be spoofed, I’d carry one.
That sounds reasonable Raf, but your ADS-B solution still places an onus on the legal pilot in Class G airspace to compensate for a new form of airspace user. Not all aircraft are equipped with ADS-B/Out now. That’s a pretty big unfunded mandate to impose on folks with simple, low-n-slow aircraft that use small uncontrolled airports/airstrips in Class G.
How is a powered hang-glider pilot supposed to verify that his newly mandated box is, in fact, working? What happens when the batteries go dead in-flight? And why should he have to accommodate for drones in the first place, when they are the new threat?
No, the burden should be placed squarely on the new vehicles, who are apparently getting their own massive chunk of airspace that, with any luck they might deign to share with us. As long as we’re willing to pony up for the privilege.
Aviatrexx, you’re correct. Pilots flying in Class G, the drone band, should not have to buy a new box just because drones showed up. The financial burden should stay on the new vehicles: drones.
Here’s the concept. I’m calling it DFR-B, just a made-up label for now. Use what most of us already fly with: iPhone, iPad, tablet, EFBs. Add a registered DFR-B Mode switch, like Airplane Mode. Turn it on and it broadcasts a short-range “manned priority here” beacon over Wi-Fi/Bluetooth that drones must honor. It is not ADS-B Out. It’s a separate protective signal that triggers the drone to get out of the way.
DFR-B is the drone-side rule engine. It runs all the time. If the drone sees ADS-B traffic or receives a valid DFR-B beacon, it executes: slow/descend/hold/land. No exceptions. If it can’t verify the signal or prove it’s clear, it goes conservative moving away.
You asked about hang gliders. The app needs “broadcasting/verified,” self-test, and low-battery alarms. iPhones, iPads, tablets, EFBs can do that. DFR-B can’t be a single-point failure.
Drones already enter controlled airspace with prior authorization (LAANC/DroneZone), including surface Class E. That’s a permission gate. DFR-B adds a mandatory yield gate.
Funding stays on drones: registration fees, higher for BVLOS and commercial, to pay for the spec, spoof-resistant security, EFB integration, compliance testing, and enforcement. Yes, a drone tariff.
I’m not sure it 100% matches what you are saying Raf, but your comments reminded me of something – IFF in ballistic missiles. IFF (Identify Friend or Foe) is a circuit in the missile that broadcasts throughout flight, from launch to detonation. That way our pilots aren’t out trying to shoot down our own missiles during any sort of conflict. Right signal, the pilot lets the missile past. Wrong signal, and they shoot them down.
Can’t help but think something that parallels that kind of thinking/design would work for drones. The drones senses a signal and boom, they set down, period. I know, I know, the idea doesn’t 100% translate because it should be on the drone to identify the aircraft, not the other way around. I’m just thinking conceptually…
Ken, IFF is exactly where we got our modern day “transponders”. The problem is not in getting the drones to receive an IFF broadcast, it’s that every aircraft that doesn’t want to get shot down, must now have electronics that were never required before. The reductio-ad-absurdum argument is that flying a kite would require an IFF transponder.
Cogently presented argument, Raf. I appreciate your aviation experience and contributions to it. However …
Your solution probably would be feasible for my elderly C-172A. However, I built and fly an Experimental single-place helicopter. Not only is there no room in it for an i-Anything, there is no place in the cockpit (including my helmet) where it would be readable (forget usable) with all the inherent vibrations. And, of course, a third arm.
No doubt the pilots of ultralights, powered-parachutes, and many other aircraft that put the “minimum” in Minimum-Equipment-List, would have similar issues. Not too many Mooneys spend a lot of time at those low altitudes (unless they’re shooting an approach) but that’s exactly where such minimal aircraft live.
The most salient objection to your solution is that you (and the FAA) are still placing the onus on us, the existing legal users of low-altitude Class G airspace, to protect ourselves from highly mobile air-mines lacking the self-preservation instincts of the aforementioned turkey buzzard. This is not an insurmountable technical problem. In my software development days, we called it a SMOP, a “simple matter of programming”.
When I lived in Maryland and started commuting regularly from my grass strip to KIAD to catch airliners to the west coast, I had to upgrade my airplane to conform to the IFR and airspace requirements of that facility. It was worth it because I gained a huge benefit over driving.
This is not the same situation. Here, I’m losing safe access to the airspace I have used for decades.
All so Amazon can lay off more workers.
As a reminder
“Here’s the concept. I’m calling it DFR-B, just a made-up label for now. Use what most of us already fly with: iPhone, iPad, tablet, EFBs. Add a registered DFR-B Mode switch, like Airplane Mode. Turn it on and it broadcasts a short-range “manned priority here” beacon over Wi-Fi/Bluetooth that drones must honor. It is not ADS-B Out. It’s a separate protective signal that triggers the drone to get out of the way.”
” Not only is there no room in it for an i-Anything,”
Don’t know about you, but I ride horses, a very minimal equipment “vehicle” yet I can record my path, speed, altitude, and time from the mobile device strapped to my arm. The onus then is downloading the app (and of course FAA approval) on the pilots side, but the bigger onus is on the drone operator to have the*required* equipment to receive the signal and react.
The salient problem is more that people do not want to pay more or do more to solve the issue and hoping that one day “it’s not them”.
I actually like the idea as mine was similar, require ADS-B OUT in all drones, but of course that only works for ADBS-IN planes and still requires pilot eyes on a screen at the wrong moment.
Overall I like RAF’s approach because not only is the bulk of the responsibility on the drone operator/owner to be required to have such technology, it allows for you hang glider pilot to opt in for safety. It is not the responsibility for the glider pilot to see and avoid, it is that of the drone.
RAF mentioned WiFi/Bluetooth as the communication protocol, but I have issues with BT. It is not a strong signal and only works over short distances. If by WiFi RAF just meant standard RF frequencies than there I agree. WiFi is typically tied to specific bands and are typically looking for specific transmission protocols. RF allows for greater distances allows to respond.
The clock is ticking. Drones are multiplying like rabbits, and the FAA, NASA, and RTCA still treat low-altitude separation like a 6th grade science fair project instead of an operational problem.
I’m curious what effect/aid AI may have on the inevitable increase in air traffic due to drones and “manned but not piloted” aircraft in the future.
Lon, that’s the right question.
What we are really talking about here is DFR: a digital separation framework for mixed low-altitude traffic, where rules and machine behavior are defined early, before conflicts get tight.
AI logic can help inside that framework. It can watch position, speed, direction, climb/descent, traffic density, and predicted crossing points, then help spot trouble early and support the safest move.
But AI logic by itself is not the safety system.
The safety system is the separation framework: who yields, when they yield, and what the aircraft or drone does automatically before traffic becomes a last-second problem.
That’s why I keep pushing DFR. AI logic can be a strong helper, but it is not a substitute for real digital separation.
NASA, RTCA, and the EU are working on pieces of this, but practical implementation is still a few years away.