Tuesday, April 16, 2013

Drones In Airspace

There seems to be a huge "land grab" trying to happen these days. Drone builders are wanting their products to be sold at all cost. I don't blame them, who doesn't want their product to sell. There are a couple issues to work out before we have our sky's filled with buzzing aircraft.

1. Safety
The airspace already has many aircraft in it. People fly their personal airplanes everyday, and there are airliners flying others even more. How are we going to insure these different aircraft don't come in contact with each other. To keep the "little guys" out of the way of the "big guys", there are specific rules. There is positive controlled airspace (the airspace between 18,000ft and 60,000ft) where anyone flying there is required to have altitude reporting transponders, and IFR flight plans and ATC is responsible for separating aircraft.

Below 18,000ft, the rules are different. Pilots are to see and avoid each other as the first line of defense. Aircraft flying easterly are to use odd thousand altitudes (IE 7000ft, 9500ft, etc), and flying westerly even thousand feet (IE 6500ft, 10,000ft). That helps separate aircraft, and mostly avoids head on collisions. The pilots are responsible for their own separation, when flying on visual flight rules (VFR). Pilots flying on  instrument flight rules (IFR) with a flight plan have ATC keeping an eye on them, as long as they are above the altitude that the RADAR can see them.

Piloted aircraft have great visibility, usually. The windows allow a wide field of view, and the pilots can rely on peripheral vision to see what is happening around them. Pilots are taught to scan the sky, and can usually pick out another aircraft well before most of the passengers even know it is there. If there is more than one pilot, the second pilot is also scanning, and the two pilots will be able to keep each other aware of any hazards.

While it sounds pretty fool proof, there are still mid-air collisions. Transitioning altitude accidents are the most common. Climbing from the departing airport to 10,000ft an aircraft will transition several even and odd thousand altitudes. If one of the pilots in that altitude, or the climbing aircraft isn't scanning, they may miss the climbing aircraft. Similar with descending from cruise altitude to the arriving airport, there may be conflicts. There are differing speeds of aircraft as well, and this can cause issues. If a 200mph aircraft is converging on a 120mph aircraft, at a 90 degree angle, even if both aircraft are going westerly, for instance, they may be in conflict, and have to avoid each other.

Drones whether remotely piloted or autonomous may pose a greater risk. They may fly following all the same rules as piloted aircraft (even/odd altitudes,see and avoid, flight plans, and ATC separation) they don't have the same capabilities. There are limitations of cameras if so equipped, communication latency, and other sensors are lacking.

The field of vision for most cameras isn't anywhere near the 180 degrees most people have of peripheral vision, and that is the biggest trouble. What the pilot can't see, they cannot avoid.  Radio waves can only go at the speed of light, maximum (roughly 1 foot per nano-second, 5280 feet in a mile = 5280 nano-seconds or about 5 micro seconds, then a thousand miles would be 5 milliseconds). What the pilot sees will have to be send via some radio from the aircraft to the pilot.

Being thousands of miles away from the actual aircraft that the pilot is flying will cause latency to the controls, that is basic physics.  It doesn't sound like much, but it matters, since what the pilot sees is from say 5 milliseconds ago, and what the pilot does takes another 5 milliseconds to start the affect. If the aircraft is satellite linked, start making that seconds, since satellites are thousands of miles up and the radio signal is not going straight up and straight down.

Communication links fail. They just do, it may be something completely random, like a backhoe taking out a ground based link. An antenna may break or fail due to ice or other cause, and sometimes radios just quit. Who controls the drone then? Maybe the drone should stop or fly in a circle until control comes back, it isn't on a flight plan at that point so what should ATC do about it? What happens when it runs out of gas, or battery? Can a drone call mayday?

There is lots of talk about aircraft broadcasting satellite based location information. The technology is there to do it, and many aircraft will in the future do that, but not all aircraft will ever. It is still legal to fly an aircraft without an electrical system. The systems to broadcast satellite based location are still thousands of dollars ($5000-10000), and this can sometimes represent more than half the cost of a whole aircraft (yes, you can buy an airplane for under $20,000), not everyone flies a multimillion dollar jet. How will the drones ever see one of these non-GPS equipped aircraft? (how about if the drone manufacturers develop a small, battery powered  $500 ADS-B in/out system that they can give to the general aviation community?)

In the current situation, a collision scenario is not an if but a when. Will it be a 747 with 300 people and a drone, or will it be a commuter jet with 50 people? Does it matter? Who will get the blame, the people who pushed the bad legislation through, or the poor pilot of the drone (could you live with yourself?)

2. Privacy
What are people wanting to do with all these drones. The manufacturers have all kind of ideas, like launching weapons, and surveillance. I don't think we need some municipality having armed drones, and the local sheriff deciding they need to get the drone out to control the crowds. 

Who will be buying and operating these drones. The manufacturers want nearly everyone to have one. More users mean more money. So maybe the local newspaper will use them to help get to a newsworthy site quickly, that seems good. What about the gossip paper, who might be nosey, or someone fishing for something to report, should they be able to go look for stuff to report?

You say, you don't have anything to hide, so it shouldn't bother you. I normally don't have anything to hide, but I don't really want free reign on people just looking! Not that anyone would want to see me naked, but do I need to close all the shades every time I am changing clothes in my bathroom with only a window well above me? Say I do something that may look shady to someone who flies over at the wrong time, might they report that?

Imagine the drones are connected with surveillance devices besides video cameras? Listening devices and radio scanning devices come to mind. Maybe someone wants to listing to what is happening below. Never mind bugging cell phones, that is too complicated. Detect things from the source. Think it can't happen?

3. Noise
The folks who don't like airports in their back yard should be all up in arms about dozens of these drones taking off and landing in their neighborhood. Many of the bigger drones will need real airports, and make real airplane noises. Smaller drones may may buzzing noises, that may not be as loud as real airplanes, but could still be annoying.

Remember the plan is to have more drones than current piloted aircraft. Lots of quiet things make a noise, anyway. What will people do about that problem. More make more noise, it all adds up.

Thoughts about solutions.

I am not totally against drones. They will have their purpose. Mostly in combat situations, not spying on the general citizens. The test areas should be out over completely unpopulated areas, like the ocean, or wide open desert areas where people don't typically fly.

If the drone builders can come up with a workable solution for the see and avoid problem, that doesn't cost the people in the civilian airspace then I could see limited mixing. It doesn't seem reasonable to make people who have nothing to do with this technology pay to make them work. (the old change the laws until your business plan works model, shouldn't apply in this situation)

Armed drones should never be allowed over civilian population, in the US or any other country. Armed drones should only be allowed in front line combat. This bit of common sense will be ignored, and people will get hurt, but it will be justified to most people.

Aviation is expensive. There are limited exceptions, but to play with the big boys, it will take real money. 

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