The unmentioned consequences of closing contract control towers

For want of a nail the shoe was lost.

For want of a shoe the horse was lost. 


For want of a horse the rider was lost. 


For want of a rider the message was lost. 


For want of a message the battle was lost. 


For want of a battle the kingdom was lost.

All for the want of a nail.

I have read much via an unlimited quantity of newsprint and pixels about the impact of the FAA’s decision to close one hundred forty eight contract control towers serving class delta airspace’s with limited volume around the United States.  In my home state of Connecticut this will shutter six airports towers leaving Bradley International as the only one in the state with an operating control tower.  As a Flight Instructor and general aviation pilot who earn wages while utilizing these services I have thought long and hard about what impact this will have on my ability to pursue my passion and generate revenue.

The news media has picked up on the narrative that there will be flight delays as the reliever airports served by contract towers will no longer be a usable by business jets in poor weather.  This will force them to utilize larger airports served by FAA staffed towers and adding additional traffic to already overburdened facilities will likely cause delays. First off for the average person this will have little or no effect on their lives. For the travelling public in major metropolitan areas the same is true. So the impact of the closures is difficult to quantify to the normal citizen. To them travelling by air is something they do on vacation and lord knows -no one goes on enough vacation.

For Ma and Pa Kettle vacationing in Hawaii or Joe Six-pack taking an occasional trip to Orlando, Cancun or Vegas their trips will likely go off as planned barring any inclement weather. Business travellers may be inconvenienced more frequently but not much surprises the travelling businessperson anymore.

At the airport my business resides next to, for a good portion of time during the year, not having an functioning control tower will have little operational impact aside from inconveniencing a handful of businesses and pilots using light aircraft in pursuit of business. To understand the implications of closing the tower one must look at what occurs when an air traffic control tower is not operating, and to do that a brief explanation of the National Airspace system is necessary.

The National Airspace System is comprised six major categories. Class Alpha (A) airspace extends from 18,000 feet to 60,000 feet and is the area where enroute air transportation usually occurs. Aircraft operating in Class A airspace are always on flight plans and are directly controlled and communicating with myriad air traffic control centers.

Class Bravo (B) is the airspace around the thirty-six busiest airports in the country. Airplanes operating within this airspace are also required to be cleared to operate within its boundaries and aside from the normal see and avoid concepts adhered to by all pilots aircraft operating within Class B are not responsible for their own separation. That is an ATC responsibility, which employs many controllers who take this very seriously.

Class Charlie(C) airspace surrounds the next tier of busy and one needn’t look farther than Bradley International in Windsor Locks CT, Albany, Buffalo, and Islip New York to get an example of what occurs there.

Class Delta (D) airspace is where the lions share of contract tower closings will occur. These are the smaller airports that serve general aviation and in some cases do have limited commercial traffic. Tweed airport in New Haven CT has limited commuter flag carriers that service the city.

Class D airspace typically extends four nautical miles from the geographical center of the airport and from the surface to twenty five hundred feet. Pilots are required to have dialog with the air traffic controllers working there and operate under a clearance to enter or depart the airspace.

Class Echo (E) airspace is controlled airspace that fills in around all the other categories of controlled airspace.  Class E can start at the surface, or 700’ Above Ground Level (AGL) or 1200’ AGL or 14000’ AGL. The way to think about Class E airspace is that it is the airspace with which all the other controlled airspace is carved out of. It fills in between Class A airspace and the tops of and in between the underlying controlled airspaces.

Class G Airspace is the mantle of low lying airspace beginning at the surface that is not Class B,C,D, or E. Class G Airspace is completely uncontrolled. The top of class G typically is at the bottom of class E airspace.

When Danbury tower is in operation (daily from 7:00AM until 10PM) the airspace surrounding the Airport is categorized as Class Delta (D) airspace. Class D airspace is controlled and pilots must communicate and receive clearance from Air Traffic Control (ATC) prior to operating within it. At 10PM the tower closes and the airspace surrounding the airport reverts to Class E until the tower opens again in the morning at 7AM. Class Echo is still controlled airspace the difference being that the start and the completion of flights no longer require communication with a controlling authority. 

This in and of itself is not particularly a problem. Pilots routinely fly into and out of non-towered class E airports all over the nation every day of the year. Pilots must obtain a clearance prior to entering controlled airspace if the weather requires such, and that can be accomplished via cell phone or radio communications. Additionally pilots must manually cancel their flight plans prior to landing with the last assigned controller -when weather permits, or via the telephone after landing when it does not. As I said earlier this happens all over the nation every single day without incident.

Where the danger to the airport and community exists is should the tower stay closed for an extended period of time. My understanding is the control towers stay closed for more than ninety days the FAA will start decommissioning them. Decommissioning is a nice word for stripping all of the equipment used by air traffic control out of the tower. The challenge for us in Danbury is that several systems instrumental towards using the airport unmonitored by ATC either wholly reside or have components of that reside in the tower.

The Pilot controlled lighting system that allows pilots to turn on the runway lights when the tower is closed is collocated inside the tower.

Additionally an Automated Surface Observation System (ASOS) serves Danbury, which is a fancy name for an unattended weather station.  The ASOS reports the weather hourly or as needed to both pilots locally via radio or telephone and is uploaded to the National Weather Service. The ASOS machine or more accurately its function in reporting of weather is what keeps the airspace surrounding Danbury class E when the tower is closed.

The transmitter for the ASOS machine also resides in the tower. If the tower closes for 90 days and its equipment is decommissioned the fate of our ASOS machine determines whether Danbury remains class E or becomes class G.

Class G airspace can be thought of as the Wild West. It is all the airspace that is not categorized as controlled and the way many remember its characteristics is by calling it “go for it” airspace. Pilots do not require a clearance to operate in class G and the weather minimums and cloud clearances limiting operations in its boundaries are liberal. Essentially flying within it is a free for all, and until the contract towers close, it is limited to the most remote of areas in our nation, typically sparsely populated mountainous areas and desert countryside’s.  Having that designation over northern Fairfield County, a scant sixty miles away from New York City is a scary proposition that will likely make even Ma and Pa Kettle sit up and take notice.