A New Way to Drive in the Sky

Imagine driving down the freeway and deciding now would be a good time to change lanes for that upcoming exit you want. You make a call (hands-free, of course) to a controller who is monitoring the freeways and request permission to change lanes for your upcoming exit. The controller is very busy handling everyone else and tells you to wait. The controller finally gets back to you and tells you that there is too much traffic, you will have to miss your exit and proceed to the next one.

This is basically how we have flown planes for the last sixty years. A radar operator in a Air Route Traffic Control Center (ARTCC) guides each plane across vast distances and then transfers control to a Terminal Radar Approach Control (TRACON) when the plane approaches a major urban center and finally to the air traffic control tower (ATCT) for the airport. Each plane must be separated by one mile horizontally and 1000 feet vertically and fly only along specified routes much like a superhighway. The separation is necessary to due something called latency. The time between sweeps of the radar when the operator doesn’t know exactly where the plane is located. This spacing means only so many planes can be stacked up on a given route. No wonder our skies are too crowded!

The FAA just received $11 Billion in funding to fully implement a new system based upon GPS. For more read the article here. It is called ADS-B (Automatic Dependent Surviellance – Broadcast).  I happened to have worked on one of the alternate ADS-B configuration back in 2007 and know quite a bit on how it works.  This system brings our air traffic control system into the 21st century by using the same GPS location technology that most people use every day in thier car or phone.  Once a plane is equipped, it can determine its position via GPS satellites. It then transmits this location to a ground system which broadcasts it to all other planes in the vicinity. Thus, the pilots not only see where their plane is at all times, but all the other planes as well. The display looks very much like a Microsoft Flight Simulator. Here is an example.

The history is that this was first fielded as an experimental system in Alaska (where radar coverage is sparse) back about ten years ago.  The system technology was selected in 2007 and the contract awarded to ITT.  They then installed the system in five test areas that represented difficult conditions such as the oil platforms in the Gulf of Mexico.  The FAA has been waiting on full funding ever since, but everyone knows the politics played with their budget culminating the the six week shutdown of all  construction over the summer.  The funding had finally been approved.  No doubt due to it being an election year.

With this system, pilots are no longer dependent on a radar technician to tell them where to go.  They can “self-separate”.  In other words, they can act just like you do when you drive down the freeway and move over because someone is too close or change lanes when you see a safe opening in traffic.  Planes also will not be restricted to specific routes in the airspace.  All of this should greatly decrease crowded skies over our busiest airports by allowing more planes to operate safely in the same amount of airspace.  The FAA will save money by not operating expensive radars and keeping so many highly paid air traffic controllers on staff.