ATCC Controllers' Read Binder...

NOTAMS, FAQs and other info for users of ATCC

December, 1997

#1: Version 1.1 (Voice Upgrade)

The version 1.1 upgrade is being shipped this month, and will also be posted to the main page of this web site. If you already have beta version 1.09C, it is essentially the same version, so you may not need to download again. If you did not order priority shipping, expect the upgrade in late December if you live in the U.S., and between January and March if you live elsewhere.

#2: Additional V1.1 Changes

Not mentioned in the November newsletter are a couple more changes in version 1.1/1.09C:

  • The NUMLOCK button is not automatically turned on, as it was in V1.0. This is to allow compatibility with some laptop computers that combine the keypad and alphanumeric keys. If you try to type numbers from the keypad, but nothing happens, turn on your NUMLOCK key.
  • Interim ("TEMP") altitudes are now displayed when aircraft come from adjacent facilities. In version 1.0, you would not see a "temp" altitude if the aircraft were coming to you from New York approach, for example, only if it were coming from another Center sector. Patches have now been installed in most real-life Approach controls, however, to allow the passing of "temp" altitudes in the datablock. Version 1.1 reflects this change, so you will get "temp" altitudes when aircraft come to you from New York and SoCal approaches.

#3: Hard Altitude Change

The datablock, of course, can hold two "assigned" altitudes: the "hard" altitude (changed with <F5>), which is usually the aircraft's requested cruising altitude, and the "temp" or "interim" altitude (<F8>), used when the assigned altitude is not the hard altitude.

In the real-life computer system, and now with V1.1 of ATCC, changing the hard altitude also changes the "requested cruising altitude" in the flight plan. Previously in ATCC, even if you changed the hard altitude in the datablock, the next controller would still try to get them to their old requested cruising altitude. No longer, however... changing the altitude with <F5> now erases the old requested cruising altitude, so the next controller will just leave them there.

In general, though, use the <F8> key to indicate altitude assignments, unless it is their requested cruising altitude, or you are climbing them to FL230 and handing off to the sector above you (i.e. in 66 and 19). If the pilot requests a new cruising altitude (due to rough rides, for example), change their altitude with <F5> instead of <F8>, to indicate to the next controller they want that new altitude as their "final."

#4: The Importance of Readbacks!

Listening to readbacks is absolutely critical in real-life ATC, and now with talking pilots becomes equally as important. Your instruction to the pilot is not complete until you have heard a correct readback... if you correctly issue an altitude of FL330, for example, but the pilot reads back FL350 (which you miss) and there is a subsequent deal, you are to blame!

Likewise, if you do not get a readback, you are required to assume the pilot did not receive the command (though it is possible they did, and are already doing it), and must re-issue it. This may typically occur after you first issue the instruction, but then a different aircraft begins talking. You might even answer that second aircraft, but you must remember to get the readback from the first aircraft, or re-issue the command.

If the pilot acknowledges with just "roger," or "copy," instead of reading back the altitude/heading/speed assignment, you are allowed to accept that as a proper readback, but there is no harm if you issue the instruction again, "just to verify" the altitude, for example.

Be fully alert when listening to readbacks! You might tell Southwest 35 to descend to FL240, but Northwest 35 may respond. If you're not fully alert, it is easy to miss, and you take the blame if there is a deal! The instruction is not complete until you have issued it and heard a proper readback... don't move on with your scan until you have heard the readback.

#5: Losing Control of your Frequency

The addition of talking pilots makes the limitations of radio communications even more obvious. You issue an instruction to an aircraft: "Delta 415, descend and maintain 14,000." Before the aircraft can even answer, somebody else checks on: "Good evening, N15J 12,000." You decide to quickly answer 15J before Delta's readback, but after you do, you get "Blocked!" Still no readback from Delta 415, so you re-issue 14,000: "Blocked!" ... <squeal from two talking at once> ... "Was that for Delta 415?" "Good evening center, UAL756 flight level 240." ...

"DELTA 415!!!! DESCEND AND MAINTAIN 14,000!!!!!!"


You've lost control of your frequency. You know what you need to say, but nobody will let you say it! Getting the proper sequencing and spacing can depend on turning aircraft precisely at the right moment, but you can't tell the aircraft to turn when everybody keeps stepping on each other.

Too bad. The same problem exists in reality, and is the true source of the Stress. You have to simply accept that occasionally you will be unable to issue timely instructions, due to radio frequency congestion. This means not relying on being able to turn them "at the last minute," because that may be when you lose control of your radios.

When you have lost control, and everybody is talking at once, the best method is to take a deep breath, key your mike, and type slowly and deliberately, to one aircraft at a time. Wait for the readback, and ignore everybody else. You are the only one with anything important to say! Move on to the next aircraft, issue the instruction, and wait for the readback. Ignore the aircraft checking on. Ignore the aircraft asking about the rides. Ignore the requests for lower. Do what you need to do, until the immediate tasks are complete. Then go back and acknowledge the check-ons, or give ride information to those who asked.

Ideally you shouldn't lose control at all. If things are starting to get busy, but are still under control, don't ignore check-ons or requests, because the pilots will assume you didn't hear them, and will keep asking. Ignore pilots only after you have lost control and need to regain it.

Other tips are to issue plain descend-and-maintain instructions instead of crossing restrictions, to keep them from interrupting you later to tell you they have started their descent. Also don't take a bunch of handoffs at the same time, as they may all try to check on at the same time. And get rid of aircraft as soon as you can... if the next sector has taken the handoff, and you are done with the aircraft, switch them to the next guy and get them off your frequency!

Congested radios indirectly or even directly cause many of the delays that exist in commercial aviation. Controllers may be able to handle more traffic mentally, but there is usually a lower limit on how many they can have on frequency at once. One shared radio frequency can quickly become filled with ride complaints or s-l-o-w talkers!

#6: Thrashing

At the other extreme to losing control of your radios is having your radios so much under control that you are tricked into thinking things aren't as busy as they actually are. The radios may be quiet, and things running so smoothly that you begin to reflexively take new handoffs without fitting them into the overall picture, subconsciously equating a quiet radio with a quiet sector. Eventually the radios will get busier, and you may forget about those new aircraft until the last minute, when you notice the conflicts and have to thrash around from crisis to crisis.

Don't let quiet radios fool you. Always make complete scans, and be sure to note where the new aircraft fit into the sector before you take the handoff!

#7: Featured Sector: ZLA 38

L.A. Sector 38 has actually been made a little busier overall, with the new version 1.1 (and 1.09C). There are now more aircraft departing BUR and VNY, to better reflect the traffic mix in the real sector 38.

The main focus of the sector is west of Hector, with the ongoing conflicts between the BUR arrivals and LAX departures. Generally, get the arrivals down and the departures up! To delay the inevitable conflict a little, clear the LAX departures direct LAS (..LAS) as soon as you can, which will move the conflict point a little further west. This gives you a little extra space to get the BUR arrivals down.

Try to take the BUR arrival handoffs as soon as you can, to be able to talk to them as early as possible. As soon as they check on, descend them to FL240 or FL200 if you know there is a conflict (in reality you would ask sector 17 for permission to descend lower than your sector bottom, and they usually approve FL200). If they are coming from the northeast, and have not yet passed over HEC and begun the turn westbound, tell them to FPH to keep them parallel to your LAX flow, then once they are below or clear of the LAX traffic, give them ..PMD.

Another good idea is to issue the BUR landers 10 west of HEC at FL240 (X10WHE240), or even lower, which they can usually accomplish if you give give the instruction prior to HEC. If the LAX traffic is direct LAS, this should provide enough separation, or you can expedite the BUR arrival further to FL200.

If the LAX departure is such a slow climber that this won't work, turn the departure to a 70 heading 10 or more miles prior to reaching J6, to parallel the BUR arrivals. Then you can keep the BUR arrivals descending and the LAX jet climbing.

Failing this, just use altitude separation, but try to get the BUR arrival down to FL250 and the LAX stopped at FL240. If the BUR arrival is stuck at an altitude much higher than FL250, it will be difficult for them to descend in time to reach the airport.

Another common conflict is between LAX departures coming from LAX then direct DAG, and the LAX or SNA departures from over POM direct DAG. Their routes eventually merge at DAG, making it difficult to climb one above the other (or creating reverse-stacks, with LAS arrivals stuck above enroute aircraft), so to resolve this issue turn the northern-most aircraft direct LAS as soon as possible, even getting on the interphone to tell sector 18 to issue it. This changes the route enough to make the two routes almost parallel, so you can safely climb or descend one through the other.

Sector 38 should also ideally get all the departures climbing to their requested cruising altitude, and lift any speed restrictions prior to giving them to the next sector (34). Some of them are flying two or three thousand miles, and it certainly isn't fair to tell them FL290 will be their "final" altitude just because you can't get them to their requested altitude of FL330. If one LAX departure is stuck underneath another, let one of them go direct to their destination, such as ..BOS or ..ORD. This will turn the aircraft to the east (still hand off to 34, though, even though it goes to sector 37), so both should be able to get to their requested altitude sooner. This technique is also used in the real-life 38, though they are given direct to a VOR further down the line, instead of direct to their destination. It has the same effect, though, pointing one of them further to the east. You are not supposed to give everybody direct to a point beyond LAS, just to the occasional aircraft to clear up a conflict.

Las Vegas Arrivals: These may come over requesting FL290 or even FL330, but that doesn't mean they have to get it. It is a short flight, and they have to cross DAG at FL240 anyway, so just give them an altitude that works best for you. The BUR departures landing at LAS, in fact, should probably be climbed just to FL240, or even left at FL230. Otherwise, they may get stuck above slow-climbing LAX departures, and you'll have very little room by DAG to descend them (the restriction to cross DAG at FL240 is what you should aim for, but is not absolutely mandatory. Sector 6 runs into problems if they are much higher at DAG, though, so do your best).

Palm Springs departures will almost always conflict with LAX departures, and you will be charged with a deal if you have handoffs on both aircraft. This is a problem in real-life, too, as the PSP departures are coming from sector 19, and the LAX departures from sector 18. Often the sector 18 controller will have already switched the LAX departure over to sector 38 when they get a panicked call from sector 19 about the PSP departure (also talking to sector 38) about to enter their sector. The three- to six human controllers (18, 19 and 38 and their D-sides) usually work out a solution quickly, but the computer is quite ignorant of this and will hand you a deal. The solution is to not take the handoff on one of the aircraft until the other is well clear, either above or laterally. If this means the LAX (or PSP) departure has to level off at FL230, so be it. As long as you don't take the handoff, you can lose separation with the other aircraft without being charged with a deal. Just get the other one climbing, and once he is out of FL240 you can safely take the handoff on the other aircraft.

Restricted Area R-2508: This is run by the military and is normally off-limits, but their controllers will let an occasional aircraft go inside, or up to the boundary, if you really have run out of options, and you talk nicely to them on the interphone. Sometimes, though, there are military exercises with live ammunition, or practice dogfights not entirely on their radar, so they will deny any requests ("point-outs") to get close to their airspace. If you let one of your aircraft stray too close (within 3 miles) of the boundary, it is an airspace violation and is considered as severe as a deal. And sector 37 may deny your requests to let your aircraft enter their sector, because they have steady streams of aircraft descending into LAX. If you don't have separation and sequencing established early, you can quickly run out of room by the time the aircraft converge over DAG.

What happens if there is a big weather cell over DAG, so the pilots won't go straight, but the military won't let them turn left, and sector 37 won't let them turn right? Too bad! This is why a lot of the real sector 38 controllers hate (fear) the sector. Run it at full intensity (100), and don't let any aircraft come within 3 miles of the R-2508 and sector 37 boundaries, all while achieving the proper (10 mile) spacing to LAS, and getting all departures up to their requested altitude. That's the real sector 38!

#8: More ATC Movies

The broadcast of the TV movie Blackout mentioned in last month's Read Binder has been rescheduled to an unknown later date, but NBC still says it is "coming soon." There are also no less than three new feature-length movies under production about Air Traffic Control, including one that has already begun filming, preliminarily titled "Ground Control." It is a drama about a burned-out Center controller, played by Kiefer Sutherland, who handles an airliner crash while working sector 75, then transfers to a smaller Center to try to escape the guilt and personal doubt he subsequently suffers. Also starring are Kelly McGillis as the facility chief, Henry Winkler as the overworked computer technician, and Margaret Cho and Charles Fleischer (, as fellow controllers, among others. Look for various ATCC sectors in the radar screen shots, and the main programmer for ATCC in a cameo as "Man #2 pointing to the left."

#9: New Version of "ORD Approach" Posted

A slightly revised version 3 of the unofficial "Chicago Approach" sector was posted to this site in mid-November, modified to enable 6-second radar sweeps and a 3-mile separation minimum when used with version 1.09B or greater. It is still an unofficial sector, is not claimed to be a completely realistic Approach sector, and is not officially supported. But, it can be interesting to run, and isn't that different than the real Chicago TRACON. Aircraft now say "cleared direct runway niner left" or "cleared direct runway two-two right" when cleared for approach, which isn't entirely realistic, but is better than the previous "direct WWWWW" and "direct SSSSS."

The next modifications to ATCC include Voice Recognition, additional Center sectors, and possibly official Approach sectors as well... send in your suggestions (and preferences) to, and we'll add them to the list!


The Read Binder is updated at the beginning of the month. All information is for use with Xavius Software's Air Traffic Control CenterTM only, is the opinion of the author(s), and does not necessarily reflect the policies or practices of the U.S. Federal Aviation Administration or Federal Aviation Service. Send your questions or comments to and we'll be glad to help!