Quadcopter Squawk capability

[Mike Watson]

What (if anything) is keeping the manufacturers of quadcopters from building in squawk / transponder capabilities, so they could be (more) easily seen on radar?

What (if anything) is holding back functionality of the quadcopter app on the tablet to also access Unicom frequencies to TX/RX?

Perhaps I'm naive, but I don't think quadcopters are being intentionally flown into controlled airspace, it's lack of knowledge/functionality.

[Paul R Johnson]

Cost! Have you seen the price of transponders? They would also have issues with needing to add in a control channel to select them, and of course how would they protect the system from idiots just dialling in any old code, maybe the one for the landing 777?

[Mike Watson]

Have you seen the price of a helicopter? Doesn't that seem to have been solved pretty easily with 2015 technology?

[Jody Arnott]

Yeah I'd say cost. I fly a microlight and even that doesn't have a transponder (and doesn't need to, legally). It amazes me that the CAA is so relaxed when it comes to microlight law, but seems to be taking a very hard approach to drone law.

NZ CAA just made it illegal to fly drones over any area (including public land) without permission). I'm now in the process of selling my drones, it's no longer worth the effort IMO.

[Paul R Johnson]

You have to remember that it's still illegal in the UK, at least, to use many frequencies up in the air. transponder transmissions are tightly controlled, because downlinks cover such a huge area. A few watts going upwards is one thing, but the same power up in the air is a very different thing. You could make the transmitted quite cheaply, but they require test house certification, and who would pay for that? The testing regulations have been softened for ground based equipment over the past 15 years, but aviation is controlled tightly. Even pilots who change their transponder code live, rather than by putting into standby first cause problems for act, as the digits are selected. Uncontrolled drones would be a nightmare and expect the CAA to hate the idea!

[Chris Medico]

Its not likely that a UAV manufacturer would include that feature in its embedded electronics. Transponders require a number of government approvals to be legal for use in the flight network. That makes it less practical for a UAV manufacturer to do. It all adds up to cost and a lot of extra time added to the development cycle.

Buying a standalone transponder (already available) is the way to go.

[John Nantz]

Originally Posted by Mike Watson

What (if anything) is keeping the manufacturers of quadcopters from building in squawk / transponder capabilities, so they could be (more) easily seen on radar?

As far as having one on board - except for [edit: possibly some] law against it - probably nothing. Cost for a cheap King transponder about $3,000 and it weighs a tad over 3 pounds, without the wire harness. Then there is the wiring and power supply. There would be no way to change frequencies or do an “ident” if the operator is on the ground.

From a radar standpoint, it could cause more problems to flight controllers and other aircraft becasue there would be a target with no information connected to it so they wouldn’t know what it was, who was flying it, or how high it was flying. Particularly in a busy airspace this couldl cause havoc.

The transponder insttallation would have to be certified by a licensed technician.

To know what altitude the craft was at there would need to be an altimeter. The altimeter must be set to an known altitude before takeoff and it is unlikely the typical operator would know how to find that out. Airports have known elevations for this purpose but elsewhere one would have to rely on Coast and Geodetic Survey benchmarks that have a surveyed elevation available. I wonder how the average operator would know how to find one nearby.

An altimeter would add more weight and require more power to operate.

Then there is still no radio communication capability. How would the operator communicate with other aircraft or Flight Service?

It’d need an antenna and a clear line-of-sight to communicate with Flight Service, towers, or other aircraft. At low level some buildings could block the signal in which case the target would come and go.

In the Pacific Northwest, Puget Sound, British Columbia, and up to Alaska, one thing of concern is that commerical Part 135 aircraft (seaplanes) routinely fly just a couple hundred feet above ground level and just below the fog overcast. I’ve had some float planes fly not too much above my mast height (~ 60 feet) and they can do this under VFR conditions. The month of Fogust is just around the corner but with this huge climate change it may be different this year.

So, can manufacturers do it? Technically, probably yes, but it probably won’t be your foam-type copter. It’d need some horsepower to lift the weight off the ground. Would people buy it? Probably not your average user.

[Chris Medico]

No need to reinvent anything. Its already available.

Sagetech | Unmanned Transponder Solutions

[Mike Watson]

That's what I'm looking for. Wonder how much they cost.

[Chris Medico]

My gut would guess between $2500 and $3500.

[Mike Watson]

I wonder how long until we overhaul this WWII era system of identifying aircraft into something more modern.

[Jim Michael]

If you get one, may as well get it with ADS-B capability. The biggest challenge is probably going to be the weight. Would you intend to put an altitude encoder on the aircraft as well? My Garmin was less the $2k US, but my useful load is about 1200 lb.

[Greg Boston]

Some good points here. I think the current drawback is weight and power consumption. I had said elsewhere that if there could be a receive only type of unit aboard the UAV, it could theoretically use a received signal to alter its course away from a manned aircraft.

As to John's statement about altitude encoding, that could be accomplished with the current GPS aboard most all UAVs. It wouldn't be pressure altitude, but rather GPS altitude. I do know that my Q500+ has a barometric sensor on it as well. I believe that sensor is for the auto land and possibly altitude hold in a hover. As to squawk code and ident, that could be done through the ground control station with a purpose designed transponder for UAVs.

Quadcopter app on the tablet would need the proper radio transceiver hardware to access Unicom. The app could be used as the user interface as well as the audio in/out path. However, because the current Unicom frequencies are VHF, they are line of sight transmission and height of the transceiver antenna is paramount to getting distant reception. Sitting here on the ground, my scanner can barely pick up the DFW airport frequencies. If I take that same scanner's antenna a couple thousand feet in the air, it would have very strong reception.

I think eventually this problem is going to sort itself out a bit. There is already the Know Before You Fly information campaign and several UAVs now have no fly areas encoded into the firmware. My Q500+ won't even spin up the props in a no fly zone such as within 5 miles of an airport. So as we go forward, education and technological solutions should reduce a lot of these incidents of improper flight.

[Paul R Johnson]

The entire drone problem is because they are too cheap. The decent operators with training spend much more money. Spending an extra grand or two wouldn't raise safety standards because the idiots wouldn't even know what a transponder was, let alone buy one!