ATC Clears

An artifact from the old days—originating in the ANC manual referenced elsewhere—was the phrase “ATC clears…”. A layman might, at first blush, figure everything an ATC says involves clears, but there’s more to it than that—way more.

In the old days—that’s pre-war days—there was no direct communication between air traffic control and the airplanes being controlled. Remember that ATC, at least insofar as enroute ATC is concerned, was started by the airlines to manage the busy New York-Chicago routes. While a consortium of the airlines controllers worked together as impartial separators of airplanes, the mainstay of communications with the airplanes—that is, the delivery of clearances—was via the companies’ radio networks—themselves nascent in development.

Quite naturally, a business opportunity arose, and Aeronautical Radio, Inc. (ARINC) was formed which contracted communications services to commercial flights who subscribed. Whether company radio or ARINC, if controllers and airplanes wanted/needed to talk to each other, it was not directly.

I can’t imagine how the thinking went at the time, but I have a high degree of confidence that lawyers were involved. The issue would have been “where’d this clearance come from?” From the pilot’s perspective, one couldn’t tell—an actual controller would sound just like a dispatcher, and frankly, the technical aspects of air/ground communication were identical between the two. Apparently a decision was made that it was important that the user knew from whom they were getting the clearance. The solution? “ATC clears”.

The system was set up so that a user getting a clearance in simple, direct terms—e.g.“climb and maintain eight thousand”—could be confident that the clearance was directly from the person separating him from other aircraft. If the clearance was preceded by “ATC clears”, they knew it had been relayed from a controller through a non-controller. I’m unsure what events might have led to this procedure, but as I suggested, lawyers and liability must have been at its root.

It wasn’t until traffic got busy enough around the major terminals that the necessity for real time communications arose that the CAA began installing two-way radio systems to communicate directly with airplanes. First the towers, of course, but approach controls, as they developed would have followed rapidly. The ARTCCs started getting radios in the ’40s, but wholesale installation and implentation of direct air/ground capability wasn't completly accomplished until after the relocation of most of the ARTCCs in the early ’60s.

When I hired in, ZJX had transmitter/receivers for every sector. It was an uncommon, although not unusual circumstance for us not to be talking to the airplanes under our control. One such circumstance, for example, was FLO. Located on the field was a FSS, which was the third leg in the communications triumvirate which included company and ARINC. They were, as the name implied a dispensary of functions and data (weather, PIREPs, NOTAMs, local traffic conditions, etc.) useful to pilots of all stripes, but principally the non-commercial, non-military community. The companies and ARINC were clearly not control facilities, and the FSS specialists, despite being in the same General Schedule pay classification as us (GS-2152) were not controllers, either, thus the distinction.

Here’s how the phrase was employed by us in real life in 1968 and throughout my career (albeit infrequently). “Ding, ding, ding” (line from FLO ringing and flashing) “Jacksonville Center,” I would respond.

“Florence Radio (that’s how FSSes were identified), request clearance on November 3485 Juliet, IFR to SAV.”

I would check my proposal bay for the flight plan, retrieve the strip, put it at the bottom of my active bay, cocked. Then, examining the flight plan, and checking my traffic, I would reply, “ATC clears 3485 Juliet to the SAV airport, via Victor 3, maintain three thousand.” There were lots of refinements, such as a transponder code, a clearance void time, if appropriate (to avoid tying up one’s airspace if the decided to taxi back to the ramp and not tell anyone—it happened), the frequency on which to contact us after departure, and other stuff which might be germane, all followed by one’s operating initials.

The clearance would be relayed to the pilot verbatim, including the “ATC clears…” Now, it sometimes happened that we had a receiver/transmitter on the field, or nearby enough to be able to talk to airplanes on the ground, and that entire transaction could have taken place at such a location, directly and without the necessity of “ATC clears…”

It turned out to be an infrequent occurence, but the procedure was in place, had meaning, and, not surprisingly, misunderstood by a lot of controllers. I heard controllers using the phrase “ATC clears” many times when it was inappropriate and worse, heard it not used when it should have been. Much like the origins of “ANC”, if one doesn’t understand the genesis of a phrase or procedure, one is very likely to use it incorrectly or not use it correctly.

Naturally, controllers, not being the pious types, would occasionally articulate “ATC dares” in the telling of a story. I’m confident I never heard it actually used in anger.

Last updated: 25 September 2012