VFR traffic advisories


Using 'the system' will improve your flying enjoyment and safety

By Robert I. Snow

Air traffic control (ATC) provides many services to pilots. Its primary job is maintaining safe separation between aircraft flying under instrument flight rules (IFR); providing navigational assistance, weather information, severe weather avoidance vectoring (to the best of its ability using radar that is not specifically designed for the purpose), and traffic advisories; and disseminating other information pertaining to safety of flight.

Pilots on instrument flight plans take these services for granted. But they are also available to visual flight rules (VFR) pilots. All you have to do is call any of the 23 Air Route Traffic Control Centers (ARTCCs, or Centers) that work the airspace between terminal areas and request VFR traffic advisories or VFR radar advisories — frequently called flight following — to take full advantage of the ATC system your tax dollars help to support.

VFR flight following offers a number of advantages that will make your flying more enjoyable — and safer. Primary among them is traffic advisories. Because you are a radar target on the controller's screen, identified by a transponder squawk code he's issued you, he'll advise you of other radar targets (airplanes) that might conflict with your route of flight. A typical advisory sounds like this: "Cessna 23 Papa, traffic, 1 o'clock, 3 miles, southbound, VFR, altitude indicates 6,500."

This information allows you to scan the appropriate sector of the sky for the traffic. As you do, you should respond to the controller with, "Cessna 23 Papa, looking." This tells the controller that you've received the message. If you spot the other aircraft, let the controller know by saying, "23 Papa, traffic in sight," or if you don't see the traffic, say, "23 Papa, negative contact."

Once the controller knows you see the traffic, he'll generally stop giving you advisories on that particular target. If you lose sight of it before it has safely passed, tell the controller; otherwise he'll assume that you're continuing to keep the other plane in sight.

Always remember that there may be other planes on the same approximate bearing that the controller can't for some reason see on radar, or that are farther away and not a factor. Even though ATC is providing traffic advisories, you, the pilot in command, are still responsible for traffic avoidance. Maintain your traffic scan at all times!

Many times you'll never see the traffic ATC has pointed out. There may be clouds between you and it (clouds do not show up on radar, so the controller won't know this), the traffic may be hidden in the glare of a setting sun, or it may just be too far away to be seen.

Center controllers use 5 miles as their separation standard between IFR traffic. In other words, they are carefully taught to take action before aircraft get within 5 miles of each other. But controllers are trained for an IFR world, and many may not realize that it's often impossible to see a light aircraft that's more than 5 miles away.

Whether or not you see the traffic, keep looking. One time the traffic may pass 6 miles away and never be seen. The next time, however, the traffic may turn toward you and pass very close, and thanks to the controller's advisory, you'll already be looking for him. And look about 30 degrees to either side of the "o'clock" direction given. While ATC radar indicates your flight path, it can't see your wind correction angle. Your 10 o'clock and the controller's may be different.

If, in the controller's judgment, the traffic will pass so close to you that a real possibility of a collision exists, making you aware of the other plane becomes his highest priority. While it's up to the controller to decide when to call and when not to call routine traffic (another reason to maintain your traffic scan), once a collision danger is recognized, the controller no longer has a choice. He must make a safety advisory.

When safety advisories are issued, they will often include an instruction to turn, climb, or descend — "Traffic, 12 o'clock, opposite direction, suggest an immediate left turn!"

The controller says "suggest" because he has no authority to require a pilot to comply if the VFR aircraft is outside of Class B or C. Under the pressure of the moment, however, a controller may omit the word "suggest." But the turn is still advisory in nature and is only the controller's best suggestion to avoid a collision.

Bear in mind that by the time the controller sees the hazard, the two radar blips may be so close that it's difficult for him to perceive the best evasive maneuver. If, in your judgment, another course of action is more prudent, remember that you are the pilot in command.

You get a lot more from flight following than just traffic and safety advisories. When there are thunderstorms around and sigmets (significant meteorological information pertinent to the safety of all aircraft) and other weather advisories are being issued, controllers will either read the advisory or declare that a new advisory has been issued and is available from Flight Service.

This service may alert you to severe weather unknown to you. And if you see questionable weather ahead, the controller may be able to ask other aircraft already in that area what the flight conditions are. This kind of real-time information can be of great help.

VFR flight following can also make navigation simpler under certain circumstances. True, providing navigational assistance is not ATC's primary purpose. If you have a private certificate or better, everyone assumes you know how to get to where you're going. And it's true that when ATC is busy, one way to really annoy the controller is to ask, "Say, Center, what's my distance to the Boondocks VOR?"

But if traffic is slow, and the controller appears to be unhurried, it doesn't hurt for the pilot of an aircraft without Loran or GPS (Global Positioning System) to ask the controller the bearing to a distant Navaid. And if you do get lost, and fuel starts getting low, the controller does have the capability of giving you bearing to and distance from any fix in his computer's memory (generally all navaids and most airports within the specific Center's area of responsibility).

If you're in trouble, admit it and get help. If there is any one reason instructors should teach their students how to contact, request, and use flight following services, this is it!

Getting lost isn't the only emergency with which Center controllers might be able to help. Systemwide, about 20 percent of controllers are pilots. Many hold commercial certificates or better. There are typically about a hundred Center controllers on duty during the day shift. This means there are about 20 pilots on duty, maybe even a couple of flight instructors. If you have a mechanical problem, ask for help. Even if none of the controllers know the answer, a local fixed-base operator (FBO) is usually only a phone call away.

For those flying with spouses, teach your significant other how to contact Center in case you become incapacitated. It's not a pleasant thought, but consider the consequences. There are numerous cases documented where pilot-controllers have successfully guided non-pilots to a safe landing.

Another flight following benefit is that it may save you some money if you're planning on an instrument rating. Learning the required IFR communication procedures and getting used to communicating with Center is one of the more challenging aspects of earning an instrument rating. But if you use flight following, you'll be listening to the controller work his IFR traffic because all civilian airplanes, airline and private, use the same Center frequencies. Because you're not under any pressure to respond or perform, you'll quickly pick up the IFR communication patterns and procedures, which puts you one step ahead when you start instrument training.

For all its benefits, VFR flight following does not absolve you of your pilot in command responsibilities. If you're receiving flight following, and you fly into another airplane, the ground, or Class B or C airspace without the required clearance, the fault is yours — not the controller's.

While the responsibility for staying clear of these "obstacles" is yours, many controllers will warn you if you are entering an area of higher terrain or getting close to Class B or C airspace. But VFR flight following is never, I repeat never, a substitute for a clearance into Class B or C airspace.

Because Center controllers live in an IFR world, many are not too knowledgeable of the VFR rules you must observe. So watch your proximity to Class B and C, and restricted areas. If in doubt, ask before you enter the area in question: "Center, verify you are coordinating clearance through Class B for me?" or, "Center, say the status of Restricted Area 6312?"

Flight following is also not a substitute for a VFR flight plan. You may hear a controller say, "I've put a VFR flight plan in the computer for you." Don't be fooled! His statement means he's entered the information on your flight so that it'll be processed to the various controllers to whom you'll be talking down the line. It is not the VFR flight plan that you file with Flight Service, and it doesn't guarantee search and rescue services.

This doesn't mean, however, that the controller won't get help for you if he knows you need it. Obviously no controller is going to say, "Roger, radar service terminated, squawk VFR, frequency change approved; good day," after you report an engine failure. But what happens if you fly out of his radar area and he's unable to contact you and let you know that he's no longer providing flight following? In that case, he'll cancel the "flight plan" and forget all about you. Thirty miles later you may make a forced landing and nobody is going to know unless you filed a real flight plan with Flight Service.

VFR pilots should also remember that their request for flight following may be denied or canceled later. It's an unfortunate aspect of the system, but when you as a VFR pilot need flight following the most (because of a heavy concentration of traffic), you are least likely to get it. This may not seem right, but when it gets busy, the controller must reduce his workload and concentrate on ATC's primary "customers" — IFR flights.

Accept the refusal gracefully. You're not being refused because the controller doesn't like little airplanes! You're welcome to monitor to the Center frequency, and if it sounds like the controller's workload has eased, you might want to try again later. Otherwise, try again on your next flight.

VFR pilots should also be aware that getting flight following depends on radar coverage. An ATC controller can't follow your flight if he can't see you. Center radars are of the long-range variety and you may well be more than 100 miles from the radar site.

Because radar is "line of sight," the farther you are from the radar site, the higher you must fly to be "seen." While it's not a guarantee, the best way to ensure that you're flying where Center radar can "see" you is to cruise at a VFR altitude that's above the IFR minimum enroute altitude (MEA).

You can find the MEA, and the frequencies by which you can contact Center to request VFR flight following on an instrument enroute navigation chart. You can get these charts at almost any airport and through most pilot supply stores. Your flight instructor can show you how to read the charts and find the MEAs and frequencies (another preparatory step for an instrument rating).

Center frequencies on enroute charts are contained in boxes with serrated edges. The civilian and military frequencies are at the bottom of the box, the location of the remote transmitter (if any) is above them, and the Center's name is on top.

Each controller is responsible for a large chunk of airspace that is broken down into smaller segments. Each segment has a separate frequency. To ensure that you contact the controller responsible for the airspace in which you're currently flying, look for the serrated box closest to your current position.

If you've just taken off, you can also find the correct Center frequency on instrument approach plates. Look for a frequency labeled "Center" or "App Con" (for approach control).

If you don't have the frequency on board, call the nearest control tower or Flight Service Station. If you're calling a tower, listen first to ensure that you won't step on another pilot's transmission, then say, "Boondock tower, Cessna 23 Papa over the Boondock VOR, what's the correct Center frequency for this area?"

The same phraseology works with Flight Service. But you can also get the Center frequency during your preflight briefing. That way, when the tower gives you, "Frequency change approved," after takeoff, you can tune and then call Center to make your flight following request.

Requesting VFR flight following from a Center is painless if you use this format (ensure the frequency is clear before transmitting): "Houston Center, Cessna 123 Papa, 4,500 feet over Boondock VOR (or about 10 miles east of the Boondock VOR on the 045? radial), request flight following."

When the controller responds to your request, be prepared to give him your type aircraft and destination. This is usually all he needs. If the controller's workload permits and he can provide flight following, he'll give you a transponder squawk code and then report that you're in "radar contact."

Generally, when you fly into airspace controlled by another controller, you'll get a new frequency to use once handed off to the next controller. If you don't get this frequency, ask for it. And when you "report in," all you have to say is, "Cessna 23 Papa, VFR, 4,500 feet."

You will often be handed off to approach controllers, who are responsible for their own chunks of air. Some approach controls will not allow Centers to transfer VFR aircraft to them. In this case, Center should terminate its service to you early enough to give you time to contact approach control.

If the Center doesn't give you the approach control frequency, ask for it. In any case, be sure that you don't enter Class B or C airspace without the appropriate clearance. And remember that even if you do get forwarded to approach control, you must hear the approach controller utter the magic words — "Cleared into Class B," if Class B is present.

VFR flight following is truly a beneficial service of which all pilots should take advantage. Some may not, however, because of hangar tales telling of increased exposure to enforcement actions. It's true that an altitude deviation or failure to adhere to any other ATC clearance can have serious repercussions for pilots on instrument flight plans. But there are no separation standards for VFR pilots getting flight following.

Unless you blunder into Class B or C airspace, or a restricted or prohibited area, it's difficult to think of any circumstance that can land you in trouble. In 12 years as a Center controller, I cannot remember my facility ever filing anything against a VFR pilot. So don't be shy about using the system. It's there for you, and it can make your flying a lot more enjoyable — and safer.


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