The Big Sky Theory

My Story of ATC for Decades


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To paraphrase Norm Abram on The New Yankee Workshop, let’s take a moment to talk about equipment. (by the way, if you’re a Norm Abram fan, check out my

You’ve already read about strips and strip holders—those have been around in one form or another since at least the ’50s—back then the strip holders were metal, and the A-Sides worked behind the sectors. Stories abound of smart assed assistants who heated up the strip holders with a lighter before sending them through to the unsuspecting D-Sides on the other side. And by the way, those bays of strip racks are called “boards” although I think only indirectly. A common term for controllers doing their job is “working the boards.” Or a staff person might need to get some currency time and he’ll be described as being “on the boards.” Current thinking, and possibly in varying degrees of implementation, is to do away with strips. I always scoffed at the idea—at least in Chicago, we had too much record keeping we had to do (altitudes, headings, speeds) to conceive of giving up strips. I’m glad I won’t see it.

As I mentioned several chapters ago, we wrote strips manually when I started, but change was coming. Jacksonville was selected as the test bed for a new computer system which would do all the flight strip processing (and at the same time, prepare the facility to have some sort of alpha-numeric radar tracking). The FDP (flight data processing) equipment was already in place when I got there and they had started testing it when I got downstairs (not to the boards—that’s a controller function). When we worked 1600-0000, they would often hold us over a couple of hours for training and testing.

As with any new system, it was not without hiccups, but it only had to work in one facility and it only had to replace flight data. Although we were, let us say, scornful, as the system was improved, it actually wound up doing a pretty good job. Of course it was late and cost too much, and it was not forward compatible. It was a one-of-a-kind—no other facility would have what we did. I don’t remember exactly when we went on line—probably sometime in 1969. We were still using it when I left in 1973, but it had been enhanced, had gotten married, and was still an evolutionary dead end.

I say gotten married because Phase II of the project was to replace shrimp boats on the radar. Oops, did I forget to mention shrimp boats? And shouldn’t I say something about radar? Okay, but I’ll have to take a side trip or two.

Side trip #1: more of a refresher actually, although I don’t think I’ve spoken to the foundation of IFR operations. I’ll say “non-tower” to clarify that the IFR operations can occur either in an en route facility (ARTCC or air route traffic control center), in an approach control (collocated with a tower), or in a separate approach control facility (such as New York’s famed Common IFR Room—now called New York TRACON). To the surprise of many people who don’t know about aviation, IFR operations can be conducted entirely without radar—not efficiently with today’s traffic, but safely. There are all kinds of rules in our ATP that specify how to keep airplanes apart, by altitude, by distance, or by time.

old Chicago Center at MDW pre-1962 (Click on picture for larger image)

For many years, all IFR operations were conducted non-radar. I’ll leave the telling of the history to others, but radar and ATC started to marry after WWII, first, mostly in approach controls. Gradually some radar was introduced into ARTCC operations. Here is a picture of some controllers I knew using radar in the old Chicago Center at MDW pre-1962. I can’t say I know whether there was any radar in the old Jacksonville Center. Part of the modernization when centers were consilidated and new facilities built in the early ’60s, however, included massive additions of radar coverage.

I can’t say how much coverage there was at ZJX on the day the new facility opened, but within the half dozen or so years from then until the day I walked in, there was coverage over the whole area (with some limitations). All of High Altitude had coverage, including our two “Ocean areas” (not oceanic, which is quintissentially non radar). Most of low altitude had coverage. We had four long range radars (ARSR—air route surveillance radar), one of which was FAA and the other three of which were FAA/DoD joint use. We also had four radars at ZAU, all of which, so far as I know, were FAA owned.

shrimp boats (Click on picture for larger image)

Side trip #2: with radar, we could now see, but how to keep track of those targets? I’m sure the innovator of target markers is lost to history. The website I stole this image from identifies the subjects to be “1940s controllers…” but I’m sure they were employing similar tracking devices when the airlines were separating traffic in the ’30s.

It’s not a particularly novel concept—you have some unremarkable and otherwise indiscernible things laying about and labels to tell them apart might be useful. Enter the “shrimp boat.” In the two enroute facilities I worked, they were pieces of plexiglass, approximately 316" thick, about 1½" long, and perhaps ½" wide (the shrimp boats at ZAU were slightly narrower than the ones at ZJX, as I recall—no doubt because we didn’t put altitudes on them at ZAU).

In use, each of the airplane targets on your scope had a shrimp boat over or near it and pointing to it (one end of the shrimp boat was cut at ≈45°) and the callsign of the aircraft written on it in grease pencil (and at ZJX, the altitude). About every two or three sweeps of the radar, the controller moved each shrimp boat to keep it close to the target as the aircraft moved over the ground. It was a completely automatic process—kind of like twirling one’s hair—as one kept track of things as one worked their position.

Now that we’ve had our side trips of knowledge, we’ll move on to NAS, Enroute Stage A, Functional Package A in the next chapter.

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Last updated: 14 September 2012