To make matters confusing, airports are generally considered controlled, which is to say towered, when they are surrounded by Class B, C, or D, but not Class E airspace. If Class G airspace is uncontrolled but Class E airspace is controlled, why isn't an airport surrounded by Class E airspace considered a controlled field? The answer can be found in understanding that Class E airspace, while controlled, has no communication requirement. Why? Because there's no tower controller to talk to. (Your best bet is to think of "uncontrolled" fields as what they are, nontowered fields.) The primary benefit of having controlled airspace where you do not need to talk to ATC comes with the higher weather minimums that Class E airspace has over Class G. And remember, all controlled airports become uncontrolled airports during any hours when the control tower is closed.
In addition, Class B and C airports are served by radar, while Class D facilities typically are not. Some Class D airport control towers do have radar, but it is there for "informational purposes only," meaning the controller must base his or her air traffic directives on actually seeing the aircraft and not on information obtained from radar, as Class B and C controllers do. Because of their radar, Class B and C airports have associated approach control facilities that assign transponder codes and control traffic arriving at, departing from, and transitioning through their airports and airspace. Class D airports almost never have their own associated approach control facility. A very few, such as Bakersfield, California, do have approach control even though there are no Class B or C airports nearby.
Once you know what sort of airspace you're operating in near a given airport, it's easy to use the right rules, tips, and procedures to operate safely and securely.
Just because an airport doesn't have a control tower doesn't mean it's a good idea to cruise around without talking to anyone, unless, of course you are flying an aircraft without radios or have had a radio failure. While there's no legal communication requirement, you should always take advantage of any tools at your disposal. If you have a radio, use it.
Many nontowered fields have busy unicom frequencies, sometimes carefully monitored by a local FBO. If you're flying to an airport with a unicom, you can use it to get an airport advisory and communicate with other pilots in the area. Call 10 miles out to request an airport advisory, which will give you information about the recommended runway to use as well as traffic pattern direction and, often, wind data. Although the runway recommendation is only a suggestion, it's generally a good idea to follow it, since that's what other traffic will be doing.
Even if there is no unicom, you should use the common traffic advisory frequency (CTAF) to announce your position and intentions as appropriate. Incidentally, when you make a radio call at a nontowered field, what you're really doing is telling other traffic who you are and what you're doing. As a result, you use the term traffic with the airport name. For example, if you were approaching Frederick Municipal Airport you might say, "Frederick traffic; Cessna Eight-One-Three-Five-Uniform; 10 miles west; two-thousand, five-hundred; request airport advisory; Frederick." Begin and end each transmission with the name of the airport to avoid confusion, as it is not unusual for two nearby airports to share a communication frequency. When that happens, it's important for everyone to know which airport you're at. And, as with other radio communications, you want to say who you are, where you are, and what you want or your intentions.
In addition, some nontowered fields have an ASOS (automated surface observation system) or AWOS (automated weather observation system) in place. These automated observations can give you information about wind direction and speed, ceiling, and runway conditions as well as notices to airmen that affect the airport. If an AWOS or ASOS is available at an airport you are visiting, you should listen to the broadcast before you enter the pattern. You can find the broadcast frequencies on your chart or in the Airport/Facility Directory (A/FD).
At nontowered fields, expect a left traffic pattern unless the A/FD, a segmented circle, traffic pattern indicators on or near the runway, or a chart tell you otherwise. Terminal and sectional charts use the letters RP and a runway number to signify right traffic for a specific runway, but don't rely on this alone. Pattern direction does not always appear on charts even when the pattern calls for right traffic.
Before entering the traffic pattern at a nontowered field, it's a good idea to overfly the airport 500 feet to 1,000 feet above traffic pattern altitude. Again, you should use the unicom or CTAF to announce your position and intentions when overflying the field. An overflight allows you to spot other traffic, visually check wind and runway conditions, and look for segmented circles or other informational guides.
In addition to traffic pattern indicators, the airport may have more than one type of wind-direction indicator, such as a windsock, tetrahedron, or wind cone. When an airport has more than one of these wind indicator types, the wind sock takes precedence and you should select your runway based on what it shows.
Once you have selected your runway - and it is up to you to choose - enter the pattern on a 45-degree angle to the downwind leg of the traffic pattern. You should announce your turn ("Frederick traffic; Cessna Eight-One-Three-Five-Uniform on a 45 for Runway 23; Frederick") and be at traffic pattern altitude by the time you turn onto the downwind leg. Incidentally, you should know that the traffic pattern altitude for light aircraft at nontowered airports is 1,000 feet above ground level (agl) unless otherwise specified in the A/FD.
When you turn downwind, you need to make another announcement. "Frederick traffic, Cessna Eight-One-Three-Five-Uniform, left downwind Runway 23, Frederick." You will make similar announcements when you turn base and final. When you turn final, it's also courteous to add the type of landing you will be making to your transmission - touch and go, full stop, stop and go, etc. This lets other pilots in a crowded pattern know what to expect from you and how long you may be occupying the runway.
You are expected to remain at traffic pattern altitude until you are abeam the numbers at the approach end of the runway where you intend to land. In addition, you should be at least one-quarter of a mile from the runway threshold when you complete your turn to final. While it's important not to be too close to the end of the runway, it's equally important not to be too far away. Unless special circumstances or the capabilities of your aircraft dictate otherwise, you should be no more than one mile from the end of the runway when you turn final.
After you've landed, you still have one more announcement to make. Tell other pilots when you are clear of the runway. "Frederick traffic, Cessna Eight-One-Three-Five-Uniform, clear of Runway 23, Frederick."
Just as there are guidelines to make your arrival at a nontowered field safe, there are guidelines for departures, too. Again, you'll want to announce when you are taking the runway for departure and your departure plans. "Frederick traffic, Cessna Eight-One-Three- Five-Uniform, departing Runway 23 to the west, Frederick."
If you are taking off from a nontowered field and remaining in the pattern, you should be within 300 feet of traffic pattern altitude when you turn crosswind. That helps other aircraft predict your location and improves your ability to see and be seen. Again, make those radio calls so people know what you're doing.
If you are departing the pattern, you should climb to traffic pattern altitude and then turn 45 degrees to the left if it's a left pattern and to the right if it's a right pattern. While this is the preferred method of leaving the pattern, it's not the only one. Crosswind and downwind departures also are acceptable. While there is no regulation specifically prohibiting straight-out departures (or straight-in arrivals), the FAA strongly discourages pilots from making them for safety reasons.
Class B airspace surrounds the nation's busiest airports, and controllers must know who is where at all times. As a result, you must request and receive clearance before entering Class B airspace and listen specifically for the words "cleared into Class B" - nothing less will do. Look for the solid blue lines on sectional and terminal area charts to find Class B airspace.
In order to fly through Class B airspace or land at a Class B airport, you must hold at least a private pilot certificate or be a student or recreational pilot who has received proper training and endorsements. Some Class B airports do not allow students or recreational pilots to land even with endorsements. For a list of those airports, see Part 91, Appendix D of the federal aviation regulations (FARs).
There are special rules for the aircraft you fly, as well. You must have a two-way radio that allows you to communicate with air traffic controllers in the area and a Mode C transponder. This is to help controllers track your aircraft with radar and provide you with separation from other aircraft for the duration of your stay in the Class B. The transponder requirement can be waived under certain circumstances. If you have a working transponder but no Mode C altitude reporting, let the controller know. He or she can issue a waiver immediately. However, if your aircraft doesn't have a working transponder at all, you'll need to submit your waiver request at least an hour in advance by calling the controlling air traffic control facility. If you are flying an aircraft under instrument flight rules, you must also have an operable VOR or TACAN receiver.
In order to fly VFR, visibility must be at least three statute miles, and you must be able to remain clear of clouds. Partly because of the lower VFR minimums and the heavy traffic, special VFR is not allowed at some airports within Class B airspace. If your chart indicates NO SVFR near an airport inside Class B, then you know you cannot operate there under special VFR rules which require one mile visibility and that you remain clear of clouds. Airports that do not allow special VFR are also listed in FAR 91, Appendix D.
Inside Class B airspace, the speed limit is 250 knots indicated airspeed - not a problem for most training aircraft. Below Class B airspace and within VFR corridors through Class B, the speed limit is 200 kt indicated-still no problem for your average training airplane. In fact, you're more likely to run into difficulty because you have trouble keeping up with the big boys. Don't be surprised if you are asked to "keep up your speed," even on final approach. The minimum controllable airspeed for the larger airplanes behind you may exceed your cruise speed. Controllers need to give those aircraft room to maneuver and give you time to get down and safely off the runway.
As a practical matter, it's important to realize that Class B airspace is extremely busy. Controllers fire off instructions at an unbelievable rate of speed. Even if you already have your private pilot certificate, it's a good idea to take an instructor with you the first time you land at an airport in Class B.
It's also a good idea to practice what you want to say well before you make that first trip. While you may take off and land at your home airport without ever speaking to a soul, at Class B airports you'll have to talk to everyone - approach control, tower control, and ground control - to land. To take off you'll need to talk to clearance delivery, ground control, tower controllers, and departure control to help you transition out of the area. Just as you need a clearance to get into Class B airspace, you need a clearance to leave it. Radar service is not necessarily terminated when you leave the Class B - the controller will tell you if he or she ends your radar service.
Be prepared. Know what information each of these controllers needs from you and what information you can expect from each of them. Perhaps most important, be flexible. With so many airplanes of different sizes and capabilities to accommodate, controllers have to do a little juggling. Don't be surprised or get flustered if the instructions they give you change from one second to the next.
Compared to Class B, getting into and out of Class C airspace is simple. You don't need a clearance to enter Class C, which typically surrounds commercial airports or large city airports, but you do need to establish two-way radio communications with air traffic control.
Several miles before you reach the Class C boundary, which is indicated by solid magenta lines on sectional and terminal charts, you should call the appropriate controller, usually approach control for the primary airport within the Class C. Give the controller your position, altitude, destination, and request Class C service. If the controller responds with your N number, even if the response is "Cessna Eight-One-Three-Five-Uniform, stand by," you have established radio communications and are free to enter the Class C. The exception to this, of course, is if the controller responds with your N number and then tells you to remain outside the Class C. If the controller responds to your call but doesn't use your N number in his or her transmission, you cannot enter the Class C.
Student pilots do not need any special endorsements to fly through Class C airspace or to land at the primary airport within Class C, but the aircraft they fly must have a two-way radio and Mode C transponder. As in Class B airspace, controllers may waive the Mode C requirement. Also as in Class B, controllers have access to radar that they use to separate aircraft.
While you must talk to controllers to pass through Class C, you are not required to participate in radar separation services. But, generally speaking, it doesn't make sense to fly through Class C and decline the services. Why not get help maintaining separation from other traffic and take advantage of the extra set of eyes provided by controllers when you are traveling through such busy airspace?
Most Class C airports allow special VFR operations, though it's a good idea to look for NO SVFR on charts and to check FAR Part 91, Appendix D, to be sure about a specific airport. Normal VFR operations also have higher minimums compared to Class B airspace. To operate VFR in Class C, you must have three statute miles' visibility and remain 500 feet below, 1,000 feet above, and 2,000 feet horizontally from clouds.
Class C airspace also has a speed limit - 200 kt - but as with other such limits, it's not one you're likely to have to worry too much about.
If you are landing or taking off from a Class C airport - or any tower-controlled field - you really don't have to worry too much about how to get into or depart the pattern. The controller will generally issue instructions for you to follow. But just because you are being guided by air traffic controllers doesn't mean that you abdicate your responsibility as pilot in command. You must ensure the safety of your own flight by communicating properly, looking for traffic, and being alert to wake turbulence.
While airports in Class D airspace have much in common with other tower-controlled fields, they also have some unique characteristics.
As with Class C airports, student pilots do not need a special endorsement to land or take off and aircraft must have a two-way radio. The process for obtaining clearance to enter the airspace is the same as Class C also - a controller responds to your call and includes your N number in the transmission. Unlike Class C airports, however, your clearance to enter Class D airspace will probably come from the tower controller directly. Most Class D airports do not have approach control facilities, so the tower and ground controllers - sometimes the same person - do it all. VFR minimums are also the same in Class C and Class D airspace, but special VFR is available at all Class D airports.
Some Class D airports even have radar, but that radar can be used only to provide the controller with information. The controller may not use information solely from the radar to issue instructions to aircraft.
When it's time to land, the controller will tell you how to enter the pattern, which runway to use, and when and where to report your position.
To find Class D airspace, look for the dashed blue lines on your sectional or terminal charts. The two-digit number that appears in a box inside those lines tells you the height of the Class D airspace in hundreds of feet mean sea level.
Each airport is unique, and even the same airfield can seem different de-pending on the time of year, time of day, amount of traffic, and other factors. Even so, there are rules and guide- lines that apply to every airport. Understanding those rules gives you the background information you need when you travel to a new destination for the first time. You must start with that fundamental understanding while recognizing that the rules and recommendations leave room for variety.
Don't be surprised if you arrive at a new airport only to discover that they do things a little differently than back home. For example, some controllers have pilots squawk standby (turn their transponders from the Altitude or On position to the Standby position) or turn on landing lights in the pattern. You must be ready to adjust to any particular airport's operating procedures. If you follow the FARs, the procedures in the Aeronautical Information Manual, and the guidelines in the A/FD, you can be assured of operating properly and safely.