the sUAS NPRM and ADSB

[TedK]

That might work for today while UAVs are required to be within eye sight, but don't think for a minute the UAS world is going to be happy flying them "eyes on". These units are designed for over the horizon operations operating on an Autopilot. Having the ground station transmit the ADS-B out data isn't helpful even if the data is correct as the transmit range from the ground station may be limited by terrain and they may not be transmitting from anywhere near the traffic that might be flying near their drone.

Due to their size, weight and payload is everything and becomes even more important to them than it is to us. Using the Arcuraus as an example; With an 80# gross weight, every gram added to the aircraft is a huge penalty. The weight penalty of hauling around transmitters, receivers and or strobe packages would be more detrimental than the power penalty. These systems typically have an on board dynamo type alternator and voltage regulator, so their run time is limited by fuel capacity. However, the charging system is also limited due to weight restrictions. They are already powering the autopilot and a radio link to connect with the base station, as well as control servos and probably the payload. Requiring more power for lighting and additional transmitters/receivers would also be a big weight penalty for them. Drag from the addition of external lighting could also be a bit penalty.

The best way to limit UAS systems is for the FAA to approve their operations, then micromanage (mandate) by regulation the addition of lighting, strobe packages, beacons, transponders, ADS-B transmitters and receivers, and self powered emergency locators with huge battery packs. (is any of this sounding familiar?) Once equipped, they will be incapable of flight due to the weight of the same government bureaucracy that seems determined to ground us (or price us out of aviation).

-Cub Builder

Well, today's NRPM has the UAV within line of sight.

But you are likely correct in the long run that they will evolved to BLOS ops. Regardless, the Control Station is going to have to know where the UAV is located, even if BLOS, the UAV will be reporting GPS location to the Control Station. There is no technical reason that a Control Station couldn't provide that data to ATC for inclusion on the ADS-B uplinks. With not an additional gram on the UAV.

[cub builder]

Well, today's NRPM has the UAV within line of sight.

But you are likely correct in the long run that they will evolved to BLOS ops. Regardless, the Control Station is going to have to know where the UAV is located, even if BLOS, the UAV will be reporting GPS location to the Control Station. There is no technical reason that a Control Station couldn't provide that data to ATC for inclusion on the ADS-B uplinks. With not an additional gram on the UAV.

That's my point. The ADS-B uplinks are highly unreliable, while direct transmissions between ADS-B equipped aircraft works really well. The uplinks get better as you get nearer to a combination of radar site and ADS-B tower. But if you're out any distance, the uplinks are really bad and even if you're on top of the radar site and ADS-B tower, they still aren't great.

I was out flying yesterday evening. Was in direct line of site from the nearest ADS-B tower on a mountaintop ranging from 40 to 60 NM south during the flight. For 80% of the flight, the ADS-B tower was unavailable. I would get an occasional partial burst of FIS-B data, then it would drop off line again. Last nights ADS-B performance was worse than normal, but not all that unusual. Was flying with another aircraft that only has Mode C. We were definitely within radar range and height that we should have been on Center's radar. But he only popped up as a target on my screen for roughly 2 minutes out of the 30 minutes we were flying together. When I'm flying near other aircraft with ADS-B out (whether 1090 ES or UAT), they are always there as a reliable target. This isn't abnormal. Clearly there are issues with the FAA's uplinked data being broadcast from the ADS-B towers. Out west, there are significant dead zones where there are no ADS-B towers. The lower you are, the worse it gets.

I don't want to allow the FAA to pin my safety on a highly unreliable part of the ADS-B system. Much better to be broadcasting ADS-B data directly from the UAS vehicle as the reliability is significantly better.

Additionally, by "over the horizon" operations, I mean many of these units are designed to operate autonomously without being in radio contact with their base stations, or sometimes by use of a very slow satellite phone link. The base station can't give an accurate position update to the FAA if they aren't in contact with the vehicle. And communication to the base station via a sat phone link doesn't even come close to meeting the transmission rate required for ADS-B out. In fact, even the direct radio links we used on these units wouldn't meet the ADS-B out data transmission rate.

-Cub Builder

[pacerpilot]

What we really need is legislation requiring all aircraft windows to be "blacked out" to prevent any external viewing at all. Aircraft will be required to be equipped with avionics allowing flight without any external visual reference. This legislation will be enacted without any regard to expense, available technology or infrastructure or, an aircrafts ability to even support such a system.