Nolan_Chapter_3.pdf

Air Traffic Control System Structure / 139 Airspace Classification The airspace above the United States has been categorized by the FAA into different classes, with specific requirements and different operating rules for each. The intent of the classification scheme is to provide maximum pilot fl...

Air Traffic Control System Structure / 139 Airspace Classification The airspace above the United States has been categorized by the FAA into different classes, with specific requirements and different operating rules for each. The intent of the classification scheme is to provide maximum pilot flexibility with acceptable levels of risk appropriate to the type of operation and traffic density within that class of airspace. Different airspace classifications and rules permit the FAA and other national agencies to provide varying levels of security and control. In general, the classification scheme is designed to provide maximum separation and active control in areas of dense or high-speed flight operations. In areas of light traffic, if acceptable weather conditions exist, pilots can provide much of the needed traffic separation themselves. General Categories of Airspace The airspace classification scheme essentially provides four general categories of airspace. • The first category is one in which ATC separates all aircraft, whether IFR or VFR, known as positive controlled airspace (PCA). • The second category is airspace in which ATC separates IFR aircraft but, weather permitting, VFR pilots provide their own separation, generally known as controlled airspace. • The third category is airspace within which the pilots provide all separation, known as uncontrolled airspace. • The fourth and final category is airspace within which there are special operating restrictions and rules; known as special use airspace. Positive Controlled Airspace Within positive controlled airspace, the FAA either absolutely prohibits VFR flight operations, or if permitted, separates both VFR and IFR aircraft. PCA is reserved for either very high-altitude flights at or above 18,000 feet mean sea level (MSL) or around high-density airports. Controlled Airspace Within airspace generally designated as controlled airspace, which is most but not all of the airspace overlying the continental United States, ATC separation services are provided to IFR aircraft by the FAA. IFR aircraft are authorized to fly into clouds or areas of reduced visibility and are provided ATC assistance to remain separated from other IFR aircraft. IFR aircraft, when operating in areas where weather conditions and traffic density permit other aircraft to be safely observed and avoided, are still responsible for separating themselves from VFR aircraft. VFR aircraft operating in controlled airspace are also responsible for separating themselves from all other aircraft. VFR flight operations are permitted so long as the weather conditions are sufficient to enable pilots to “see and avoid” other aircraft. 140 / CHAPTER 3 Uncontrolled Airspace In uncontrolled airspace, ATC separation services are not provided by the FAA. Whether IFR or VFR, all aircraft must provide their own separation, regardless of the weather conditions. Special Use Airspace Special use airspace has been designated by the FAA as airspace where activities that must be confined to specific areas are conducted or where restrictions must be imposed on nonparticipating aircraft. Some special use airspace, such as prohibited and restricted areas, are regulatory special use airspace and are established and described in FAR Part 73. Other areas, such as warning, military operations, alert, and controlled firing areas, are nonregulatory special use airspace that has been described in FAA Order 7400.8, Special Use Airspace. Special use airspace can lie within either controlled or uncontrolled airspace and can potentially affect both IFR and VFR aircraft. Controlled versus Uncontrolled Airspace One of the primary differences between airspace types is that air traffic control separation services can be offered only to pilots operating in controlled airspace. Additional services, such as traffic advisories and safety alerts, can be offered to aircraft flying in uncontrolled airspace but only on a workload permitting basis. Early in this century, most of the airspace above the United States was designated as uncontrolled. Only the federal airways and the airspace around very busy airports were controlled. But as air traffic increased, and the technical air traffic control capabilities of the federal government improved, additional segments of the nation’s airspace have been designated as controlled airspace. The only uncontrolled airspace left in the domestic United States exists below 1,200 feet above ground level (AGL) away from busy airports. Various names for these airspace categories and the rules for operation within each area have evolved as they were created. In time, due to the unique development of ATC within the United States, the names and rules of operation within each area became inconsistent with ICAO standards in use throughout the rest of the world. By 1992, the FAA identified and created operational rules for close to twenty different categories of airspace. Airspace Review In 1982, in an effort to standardize and simplify U.S. airspace, the FAA and representative industry groups formed the National Airspace Review (NAR) committee to begin a comprehensive review of the nation’s airspace system. In conjunction with an ICAO review commission, the NAR committee recommended that airspace over the United States be reclassified into one of six classes. These recommendations were accepted by the FAA, and implementation began in 1993. These categories of airspace are known as Class A, B, C, D, E, and G airspace. Class F airspace exists as an ICAO classification, with no equivalent existing in the United States. As currently defined, Class A, B, C, D, and E airspace is generally a form of controlled airspace. Class G airspace is designated as uncontrolled. In general, Air Traffic Control System Structure / 141 Figure 3–1. Sample flight plan form. Class A airspace is the most restrictive, where ATC provides maximum services and separation. Class G airspace, on the other hand, is the least restrictive, and few ATC services are provided. Class B, C, D, and E airspace spans the range of services. Special use airspace as defined by the FAA does not follow specific ICAO as such and is peculiar to U.S. airspace. IFR Flight in Controlled Airspace (Class A, B, C, D, and E) Within controlled airspace, air traffic controllers are required to separate IFR aircraft and participating VFR aircraft using the procedures specified in the Air Traffic Control Handbook. (These procedures are discussed in detail in Chapters 7 and 9.) Since VFR aircraft may be permitted to operate in areas of controlled airspace (sometime without contacting ATC), it remains the responsibility of IFR pilots to see and avoid these aircraft, regardless of the services being provided by the air traffic controller. Before beginning an IFR flight in controlled airspace, the pilot is required to file a flight plan (see Figure 3–1) with the FAA and receive a clearance from an ATC facility. A general aviation or corporate pilot usually files the IFR flight plan with a flight service station specialist, using the Internet or telephone, and the information is then forwarded to the air route traffic control center (ARTCC) with jurisdiction over the departure airport. Airline flight plans are typically filed directly with the FAA using stored flight plan information. If a pilot needs to file a flight plan while airborne, the ATC facility in contact with the pilot transmits the flight plan information to the proper ATC facility. 142 / CHAPTER 3 The information required on a flight plan includes the following: 1. Type of flight plan. This will be VFR, IFR, or DVFR (which is a special type of VFR flight plan used if an aircraft is entering, leaving, or transiting U.S. airspace). 2. Aircraft identification number. This is either the aircraft’s assigned serial number, if it is a general aviation or corporate flight, or the airline call sign and flight number. 3. Aircraft type and navigation equipment installed on the aircraft. The aircraft type is abbreviated, using the codes found in the Air Traffic Control Handbook. An expanded list is included in the Appendix to this book. Examples of these abbreviations include the following: Aircraft FAA Identifier Airbus A-380-800 A388 Beech 200 King Air BE20 Boeing 737-900 B739 Cessna Citation 650 C650 Cirrus SR-22 SR22 Diamond DA-42 DA42 Embraer EMB-190 E190 Gates Learjet 55 LJ55 General Dynamics F16 Falcon F16 Piper PA-28 Warrior P28A The pilot must also identify the navigational capabilities of the aircraft by appending a unique suffix code to the aircraft type. The equipment codes are found in the handbook. The aircraft type is separated from the equipment code with a slash. The equipment codes are as follows: Suffix Equipment Capability NO DME /X No transponder /T Transponder with no Mode C /U Transponder with Mode C DME /D No transponder /B Transponder with no Mode C /A Transponder with Mode C TACAN ONLY /M No transponder /N Transponder with no Mode C /P Transponder with Mode C Air Traffic Control System Structure Suffix / 143 Equipment Capability AREA NAVIGATION (RNAV) /Y LORAN, VOR/DME, or INS with no transponder /C LORAN, VOR/DME, or INS, transponder with no Mode C /I LORAN, VOR/DME, or INS, transponder with Mode C ADVANCED RNAV WITH TRANSPONDER AND MODE C /E Flight Management System (FMS) with DME/DME and IRU position updating /F FMS with DME/DME position updating /G Global Navigation Satellite System (GNSS), including GPS or Wide Area Augmentation System (WAAS), with enroute and terminal capability /R Required Navigational Performance (RNP). The aircraft meets the RNP type prescribed for the route segment(s), route(s), and/or area concerned REDUCED VERTICAL SEPARATION MINIMUM (RVSM) /J /E with RVSM /K /F with RVSM /L /G with RVSM /Q /R with RVSM /W RVSM 4. The aircraft’s cruising true airspeed in knots. 5. The abbreviation for the departure point. This is normally the departure airport but can be an en route fix. 6. The proposed time of departure. 7. The pilot’s requested cruising altitude. 8. The requested route of flight. This must include the airway and navigation aid identifiers. The entire route of flight must be specified. When changing from one airway to another, the intersection fix must be specified. If no airway is being used, only the navaids need to be specified. For example, the route ALB J37 BUMPY J14 BHM would be interpreted as departing Albany, New York, flying via Jet Route 37 until reaching the BUMPY intersection, transitioning to Jet Route 14 at BUMPY intersection, then flying via Jet Route 14 to the destination which is Birmingham, Alabama. The route ALB BHM would be interpreted as departing Albany and flying in a straight line (direct) to the destination airport at Birmingham. 9. The destination airport. 144 / CHAPTER 3 10. The estimated time en route in hours and minutes. 11. Any pertinent remarks. 12. Fuel on board the aircraft expressed in hours and minutes. 13. The pilots selected alternate airport if on an IFR flight plan and if required by the appropriate FARs. 14. Name and address of the pilot in command. 15. Number of people on board. 16. Color of the aircraft. 17. Contact information at destination airport. Air Traffic Control Clearance The flight plan is then filed and processed by the FAA. A VFR flight plan is kept as a record for possible search and rescue if the aircraft is reported lost or overdue. An IFR flight plan is processed and an air traffic clearance is generated. Pilots operating IFR in the air traffic control system must then be issued a clearance by ATC prior to beginning their flight. This clearance must include the following information and should be communicated to the pilot in this sequence: 1. Aircraft identification. Sample phraseology: “Cherokee five one four papa uniform,” “United seven thirty-one,” “JetBlue fifteen forty-three.” 2. Clearance limit. This is the farthest location to which the aircraft is cleared to fly. Although the clearance limit is typically the destination airport, it may be an intermediate navigation aid or intersection located along the route of flight. If the clearance limit is not the destination airport and the pilot does not receive an additional clearance before reaching the clearance limit, the aircraft will enter a holding pattern at that point. (“Cleared to the Lafayette Purdue University Airport,” “Cleared to the Boiler VOR,” “Cleared to the Staks intersection.”) 3. Departure procedure. If the assigned route of flight does not begin at the departure airport, it is necessary for the controller to assign a departure procedure (DP) so that the aircraft can intercept the route of flight. Departure procedures may also be used to ensure that the aircraft avoids areas of obstructions or high-density traffic. Departure procedures direct the pilot to turn or fly a particular heading or route. If a particular departure instruction is routinely issued to most of the departing aircraft, it may be incorporated into and published as a charted DP (see Figures 3–2 and 3–3). DPs are constructed by the FAA and are published and sold by the same agencies that publish instrument approach charts. Routine use of DPs relieves controllers from repeating the same departure clearance to every aircraft. If a DP is to be used in a departure clearance, the controller assigns the DP procedure by simply including its name in the clearance. (“After departure, turn left heading three five zero,” “After departure, fly runway heading,” “O’Hare one departure.”) 4. Route of flight. The route of flight issued includes any airways or VOR radials that the pilot will use when navigating to the clearance limit (“Via victor two fiftyone,” “Via direct Danville,” “Via the Boiler one eight five radial and the Danville zero niner radial.”). The route of flight must include at least two fixes (departure and arrival airports) and the route to be flown between each fix. Intermediate fixes along the route to be flown are not routinely included as part of the clearance. The only time an intermediate fix is included in a clearance is when the fix defines a transition from one route to another (see Figure 3–4). Air Traffic Control System Structure Figure 3–2. Standard departure procedure (vector) for Atlanta Airport. / 145 146 / CHAPTER 3 Figure 3–3. Departure procedure (pilot navigation) for Alton, Illinois. Air Traffic Control System Structure / BOILER 115.1 BVT 98 13 158 186 5 ZOFRI T BV 9 V3 V9 7 9 V3 99 P VH BVT V7 P OTES POTES BV T V2 4- VH P0 17 OCKEL 12 8 V1 28 ZI PP Y V9 JAKKS VH P 7 VH P V2 4- 12 8- V7 39 9 JELLS ZIPPY 31 1 RD BRICKYA 110 P H 116.3 V Figure 3–4. Sample route of flight. 017 ADVAY 147 148 / CHAPTER 3 5. Altitude assignment. The controller should attempt to issue the pilot an altitude that conforms to the procedures contained in the ATC handbook. The proper use of such altitudes will organize the flow of traffic and reduce the hazard of midair collisions, since each aircraft operating at the same altitude will be traveling in roughly the same direction. If circumstances require that a different altitude be issued to an aircraft, the controller is permitted to assign a nonstandard altitude, but advance coordination with adjacent ATC facilities must be accomplished, advising the next controller that the aircraft is not at the proper altitude. Table 3–1 provides handbook guidelines for altitude assignment. When issuing clearances, a controller should never assign an altitude lower than the minimum en route altitude (MEA). The controller should also attempt to assign an altitude as close as possible to that filed in the original flight plan. To meet these two requirements, the controller may assign a sequence of crossing altitudes that will ensure that the aircraft is never below the MEA. These altitude instructions should be issued to the pilot in the order that they will be flown. If an altitude lower than an en route MEA is assigned initially, the pilot should be told the expected final altitude and when that altitude assignment can be expected. In case of radio failure, the pilot will remain at the assigned altitude until the time has elapsed and will then climb to the higher altitude. (“Maintain six thousand,” “Maintain four thousand until Danville, then maintain six thousand,” “Maintain niner thousand. Cross Danville at or above five thousand,” “Maintain four thousand; expect six thousand one zero minutes after departure.”) Table 3–1. Guidelines for Altitude Assignment Aircraft Operating On course Degrees Magnetic Assign Below 3,000 feet above surface Any course Any altitude At and below FL 410 0 through 179 Odd cardinal altitude or flight levels at intervals of 2,000 feet 3,000, 5,000, FL 310, FL 330 180 through 359 Even cardinal altitude or flight levels at intervals of 2,000 feet 4,000, 6,000, FL 320, FL 340 0 through 179 FL 450, FL Odd cardinal flight levels at intervals of 4,000 feet beginning 490, FL 530 with FL 450 180 through 359 Odd cardinal flight levels at FL 430, FL intervals of 4,000 feet beginning 470, FL 510 with FL 430 Above FL 410 Examples Air Traffic Control System Structure / 149 6. Holding instructions. If it is necessary to hold an aircraft over a particular fix while en route to the destination airport, the following information must be included in the holding instructions (see Figures 3–5 and 3–6). • The direction of holding from the fix, using the eight points of the compass: north, northeast, east, southeast, and so on. • The name of the holding fix. Abeam Holding side Outbound Fix end Reciprocal Outbound end Inbound Fix Nonholding side Holding course Figure 3–5. Holding-pattern description. OM L L MM Runway Typical procedure on an ILS outer marker VOR VOR Typical procedure at intersection of VOR radials Holding course away from navaid Holding course toward the navaid VORTAC 15 n mi DME fix 10 n mi DME fix Typical procedure at DME fix Figure 3–6. Examples of holding. 150 / CHAPTER 3 • The radial, course, bearing, azimuth, airway, or route on which the aircraft is to hold. • The direction of the turns in the holding pattern if a nonstandard holding pattern will be used. A standard holding pattern requires right-hand turns; a nonstandard pattern uses left turns. • The holding-pattern length if a nonstandard holding pattern is being used. A standard holding pattern has a 1-minute inbound leg length (1 ½ minutes inbound leg length if the aircraft is holding above 14,000 feet). • The Expect further clearance (EFC) time. If pilots lose radio contact with ATC, they are expected to remain in the holding pattern until the EFC time, after which they will depart the holding pattern and continue along the route of flight issued in the last clearance. (“Hold northwest of Boiler on the three two three radial. Expect further clearance at one five three five,” “Hold southwest of Vages on victor two fifty-one. Expect further clearance at two three four one.”) • The pilot is expected to enter the holding pattern using the procedures described in the Aeronautical Information Manual. The pilot will maneuver the aircraft so as to track inbound on the assigned course and will attempt to make the inbound leg 1 minute in length. This is the only way in which a pilot can hold and accurately time the inbound leg length. Air traffic controllers should never issue holding instructions that require a pilot to hold outbound from the holding fix. Since the inbound leg would not be located along any defined course, it would be impossible for the pilot to hold properly. • Any additional clearance information. This information might include position reports or arrival procedures. Required reports include crossing certain navigational fixes or changes in altitude. Arrival procedures may also be included in this portion of a clearance. An arrival clearance could be either a standard instrument approach procedure or a standard terminal arrival route (STAR) clearance (see Figures 3–7 and 3–8). STARs are similar to departure procedures and describe a common arrival procedure. (“Via the Indy one arrival.”) 7. The departure control frequency and transponder code assignment. (The operation and use of a transponder are covered in Chapter 8.) (“Departure control frequency one two three point eight five. Squawk zero three four five.”) An entire IFR clearance to an aircraft operating in controlled airspace will usually include most of the preceding components. The proper phraseology that should be used when issuing an IFR clearance is included in Chapter 4. A few examples of IFR clearances are as follows: “United six eleven cleared to the Chicago O’Hare Airport via direct Boiler, victor seven, Chicago Heights, direct. Maintain seven thousand. Departure frequency one two three point eight five. Squawk five five four five.” “Cherokee two three two papa alpha cleared to the Indianapolis Airport via the Chicago eight departure over Boiler, victor ninety-seven and the Indy seven arrival. Maintain three thousand, expect eight thousand five minutes after departure. Departure frequency one two eight point zero five, squawk five five four three.” Air Traffic Control System Structure Figure 3–7. Standard terminal arrival route chart for Orlando, Florida. / 151 152 / CHAPTER 3 U.S. TERMINAL PROCEDURES PUBLICATION: Aeronautical Information STANDARD TERMINAL ARRIVAL (STAR) CHARTS DEPARTURE PROCEDURE (DP) CHARTS RADIO AIDS TO NAVIGATION VOR TACAN VOR/DME NDB/DME VORTAC LOC/DME 58 STANDARD TERMINAL ARRIVAL (STAR) CHARTS DEPARTURE PROCEDURE (DP) CHARTS ROUTES LOC NDB (Non-directional Beacon) LMM, LOM (Compass locator) Marker Beacon Localizer Course SDF Course SPECIAL USE AIRSPACE ALTITUDES Localizer Offset 5500 2300 Mandatory Altitude Minimum Altitude (Cross at) (Cross at or above) 4800 Maximum Altitude 2200 Recommended Altitude (Cross at or below) AIRPORTS STAR Charts REPORTING POINTS/FIXES WAYPOINTS DP Charts NOTES (NAME) (" " omitted when it conflicts with runway pattern) WAYPOINT (Compulsory) WAYPOINT (Non-Compulsory) FLYOVER POINT MAP WP (Flyover) W Figure 3–8. Standard terminal arrival route chart legend. WAAS VNAV outages may occur daily due to initial system limitations. WAAS VNAV NOTAM service is not provided for this approach. Air Traffic Control System Structure / 153 Clearance Amendments As the IFR flight progresses toward the destination airport, the clearance may need to be amended by ATC. The entire clearance need not be repeated, only those items that have been changed by the controller. For example: “Five four papa uniform, climb and maintain seven thousand.” “United six eleven cleared to the Indianapolis airport via victor ninety-seven west.” “American two thirty-one, descend and maintain four thousand, cross two zero DME southeast of Boiler at or below niner thousand.” IFR Flight in Uncontrolled Airspace IFR flight in uncontrolled airspace is permitted so long as the pilot and aircraft are properly certified. The FAA does not provide any air traffic control services however. It is up to the pilot to maintain separation from other aircraft and from obstacles on the ground. In general, aircraft seldom make long IFR journeys in uncontrolled airspace, but sometimes they need to transit uncontrolled airspace while landing or departing from small, uncontrolled airports. Controllers must be aware that the pilots might be maneuvering or flying a specific course that provides terrain and/or aircraft separation while within uncontrolled airspace and that the controller should never issue instructions that would negate the pilot’s need to conform to VFR flight regulations while within uncontrolled airspace. ATC clearances to operate are never issued to aircraft (either VFR or IFR) flying in uncontrolled airspace. VFR Flight in Controlled Airspace In controlled airspace, the FAA offers both separation and additional ATC services to pilots. However, depending on the type of flight and the category of airspace involved, the pilot may not be required to use these services or even to contact air traffic control facilities. Within controlled airspace, IFR flights are required to receive these services, but VFR flights may not be. In general, as long as VFR pilots can meet the weather minima outlined by Federal Aviation Regulation (FAR) 91 and are not entering any special use airspace, no contact with ATC is required. VFR pilots may fly in controlled airspace as long as they comply with the following regulations included in FAR 91: 1. VFR pilots must generally provide their own separation from other VFR and IFR aircraft and the terrain. 2. VFR pilots are not required to file a flight plan or contact ATC unless they are planning to enter an area of restricted class airspace where contact is mandatory. VFR flight plans are voluntary and are used by the FAA only to assist in locating lost or overdue aircraft. 3. The weather conditions during flight must meet the criteria specified in FAR 91.155. VFR pilots must also maintain the minimum cloud distance stipulated in the FARs. The minimum visibility and distance from the clouds vary with the aircraft’s cruising altitude and the class of airspace within which the flight is operating. See Table 3–2. 154 / CHAPTER 3 Table 3–2. VFR Weather Minima for Operations in Controlled Airspace Airspace Flight Visibility Distance from Clouds Class A airspace Not Applicable Not Applicable Class B airspace 3 statute miles Clear of Clouds Class C airspace 3 statute miles 500 feet below 1,000 feet above 2,000 feet horizontal Class D airspace 3 statute miles 500 feet below 1,000 feet above 2,000 feet horizontal 3 statute miles 500 feet below 1,000 feet above 2,000 feet horizontal Class E airspace Less than 10,000 feet MSL At or above 10,000 5 statute miles feet MSL 1,000 feet below 1,000 feet above 1 statute mile horizontal These minima are designed to maximize the chances of a VFR pilot seeing and avoiding other VFR and IFR aircraft. If the pilot is unable to comply with these minima, VFR flight cannot legally be conducted. The pilot must then either land or receive an IFR or a special VFR clearance to continue the flight. There are additional regulations governing special VFR flights with which pilots must conform. In general, a special VFR clearance permits a VFR pilot to fly in certain weather conditions that do not meet minimum VFR criteria. VFR aircraft operating under special VFR clearances are afforded IFR separation from both VFR and IFR aircraft by ATC, however. 4. VFR pilots operating in controlled airspace are required to fly at the proper altitude for the direction of flight unless otherwise requested by ATC. FAR 91.159 describe the approved cruising altitude or flight levels to be used by VFR aircraft in controlled airspace. An aircraft operating under VFR in level cruising flight more than 3,000 feet above the surface is required to maintain the appropriate altitude or flight level prescribed here, unless otherwise authorized by ATC: • When operating below 18,000 feet MSL and on a magnetic course of zero degrees through 179 degrees, any odd thousand foot MSL altitude ⫹500 feet (such as 3,500, 5,500, or 7,500) or • When operating below 18,000 feet MSL and on a magnetic course of 180 degrees through 359 degrees, any even thousand foot MSL altitude ⫹500 feet (such as 4,500, 6,500, or 8,500) These altitudes were chosen to minimize the potential for midair collisions between two aircraft flying in opposite directions. Whenever assigning altitudes to VFR aircraft, controllers should attempt to comply with this regulation. However, if traffic conditions dictate, controllers are permitted to assign a nonstandard cruising altitude to VFR aircraft receiving ATC services. When these ATC services are terminated, however, the VFR pilot should be advised to return the aircraft to the proper altitude as soon as it is feasible. Air Traffic Control System Structure Table 3–3. / 155 VFR Weather Minima for Operations in Uncontrolled Airspace Airspace Flight Visibility Distance from Clouds Daylight flight at 1,200 feet or less AGL 1 statute mile Clear of clouds Nighttime flight at 1,200 feet or less AGL 3 statute miles 500 feet below Class G: 1,000 feet above 2,000 feet horizontal Daylight flight at more than 1,200 feet AGL but less than 10,000 feet MSL 1 statute mile 500 feet below 1,000 feet above 2,000 feet horizontal Nighttime flight at more than 1,200 feet AGL but less than 10,000 feet MSL 3 statute miles 500 feet below 1,000 feet above 2,000 feet horizontal Any VFR flight at more than 1,200 feet AGL at or above 10,000 feet MSL 5 statute miles 1,000 feet below 1,000 feet above 1 statute mile horizontal VFR Flight in Uncontrolled Airspace In uncontrolled airspace, the FAA does not provide separation services to pilots, and clearances are never issued. In general, as long as VFR pilots can meet the weather minima outlined by FAR 91 (see Table 3–3), and are not entering any special use airspace, no contact with ATC is required to fly in uncontrolled airspace. In uncontrolled airspace: 1. VFR pilots must generally provide their own separation from other VFR and IFR aircraft and the terrain. 2. VFR pilots are not required to file a flight plan or contact ATC. 3. The weather conditions during flight must meet the criteria specified in FAR 91.155. Airspace Classes In addition to the general operating rules and procedures previously stated, additional flight requirements and ATC services are provided depending on the airspace classification. All the airspace above the U.S. has been designated by the FARs into one of six classes (see Table 3–4). No services required nor will clearances be issued. If traffic conditions permit, IFR aircraft might be provided traffic advisories and flight following. Standard separation between IFR aircraft. (3 nm or 1000' vertical radar separation or standard nonradar separation). Standard separation between IFR aircraft. (3 nm or 1000' vertical radar separation or standard nonradar separation). Standard separation between IFR aircraft. (3 nm or 1000' vertical) Standard separation between IFR aircraft. (3 nm or 1000' vertical) Standard separation (5 nm or 1000') applied to all aircraft Services Provided by ATC to IFR Aircraft ATC does not offer separation services to either IFR or VFR aircraft. ATC clearance required for IFR. VFR aircraft are not required to contact ATC. ATC clearance required for IFR. VFR aircraft must make radio contact prior to entry. ATC clearance required for IFR. VFR aircraft must make radio contact prior to entry. ATC clearance required for both IFR and VFR ATC clearance required for both IFR and VFR Aircraft Entry Requirements IFR and VFR if weather conditions permit IFR and VFR if weather conditions permit IFR and VFR if weather conditions permit IFR and VFR if weather conditions permit IFR and VFR if weather conditions permit IFR only Flight Operations Permitted Uncontrolled Controlled Positive controlled Positive controlled Level of Control Airspace not included in Class A, B, C, D or E designations Airspace floor varies between the surface of the Earth, 700⬘ or 1,200' AGL. Airspace extends up to but not including 18,000 MSL Surrounding nonradar control towered airports up to an altitude of about AGL Surrounding medium-density airports up to an altitude of about AGL Controlled Surrounding high-density airports up to an altitude of about 10,000' AGL Altitudes at and above 18,000' MSL Dimensions Class G Class E Class D Class C Controlled Class B Class A Airspace Features Table 3–4. Airspace Classification 156 / CHAPTER 3 Clear of clouds 500' below, 1,000' above, and 2,000' horizontal. VFR not allowed Minimum Distance from Clouds for VFR Aircraft Entry Requirements Flight not permitted Flight of aircraft is prohibited based on security or other reasons associated with the national welfare. Prohibited Area IFR flight not permitted IFR Restrictions VFR flight not permitted VFR Restrictions 500' below, 1,000' above, and 2,000' horizontal. 500' below, 1,000' above, and 2,000' horizontal. Airspace Description and Use 3 statute miles None required. If traffic conditions permit, VFR aircraft might be provided traffic advisories and flight following. 3 statute miles Provide traffic information concerning IFR and known VFR aircraft Airspace 3 statute miles 3 statute miles VFR not allowed Aircraft will be separated from IFR or VFR aircraft by either target resolution, visual, or 500' vertical separation. Minimum Visibility for VFR Aircraft Aircraft will be separated from small IFR or VFR aircraft by either target resolution, visual or 500' vertical separation. Aircraft will be separated from large or jet IFR aircraft by either 1 ½ nm or 500' separation. VFR aircraft not permitted Services Provided by ATC to VFR Aircraft / (continued) Charted and identified on both IFR and VFR charts. Identification numbers prefixed with the letter “P”. Charting Clear of clouds 1 statute mile No services required nor will clearances be issued. If traffic conditions permit, VFR aircraft might be provided traffic advisories and flight following. Air Traffic Control System Structure 157 Charted and identified on both IFR and VFR charts. Identification numbers prefixed with the letter “R”. The pilot must contact the controlling agency to determine the areas, status. If the restricted area is not active, VFR aircraft may operate in the restricted airspace without specific clearance to do so. If the restricted area is active, it is the VFR pilots, responsibility to avoid the area. A notice to airmen will be issued restricting VFR flight. It is the pilots, responsibility to remain clear of the TFR airspace. If the restricted area is not active and has been released, ATC will allow the aircraft to operate in the restricted airspace without issuing specific clearance for it to do so. If the restricted area is active, ATC will issue clearances which ensures IFR aircraft avoidance. IFR aircraft are not normally routed into or through a TFR unless its mission is specifically related to the TFR. Aircraft entry might be permitted if restricted area not in use (cold). Aircraft entry not permitted when area is “hot.” The amount of airspace needed to protect persons and property or provide a safe environment for rescue/relief aircraft operations is normally limited to within 2,000 feet above the surface and within 3-nautical miles Incidents occurring within Class B, Class C, or Class D airspace will normally be handled through existing procedures and should not require the issuance of temporary flight restrictions. Flight of aircraft, while not wholly prohibited, is subject to restrictions. Restricted areas denote the existence of unusual hazards to aircraft such as artillery firing, aerial gunnery, or guided missile practice. TFRs are issued to protect persons and property within the vicinity of an emergency on the ground. Examples include: gas leaks or spills; volcanic eruptions; hijacking incidents, aircraft accident sites; wildfire suppression; disaster areas; aerial demonstrations or major sporting events; or reasons of national security. Restricted Area Temporary Flight Restrictions Normally not placed on IFR or VFR navigation charts. Might be charted as a graphic NOTAM. Charting VFR Restrictions IFR Restrictions Entry Requirements Airspace Description and Use Airspace 158 / CHAPTER 3 No restrictions on VFR aircraft. IFR aircraft might be permitted entry if MOA is cold but will not be permitted when area is “hot”. Flight plan must be filed. Aircraft must make contact with ATC prior to ADIZ entry. MOAs consist of airspace of defined vertical and lateral limits established for the purpose of separating certain military training activities from IFR traffic. Examples of activities conducted in MOAs include, but are not limited to, air combat tactics, air intercepts, aerobatics, formation training, and low-altitude tactics. Military pilots flying in an active MOA are exempted from the FAR which prohibits aerobatic flight within Class D and Class E airspace and within Federal airways. DoD aircraft operating within an MOA are authorized to operate aircraft at airspeeds in excess of 250 knots. An area of airspace over land or water, extending upward from the surface, within which the ready identification, location, and control of aircraft are required in the interest of national security. Military Operations Area ADIZ Pilots operating under VFR are permitted to enter an MOA without clearance but should exercise extreme caution. Pilots can contact any FSS within 100 miles of the area to obtain accurate realtime information concerning the MOA hours of operation. Depending on ATC capabilities and workload, VFR pilots may be able to contact the controlling agency for traffic advisories. VFR pilots must file D/VFR flight plan and initiate contact with ATC prior to entering ADIZ If the MOA is not active and has been released, ATC will allow the aircraft to operate in the airspace without issuing specific clearance for it to do so. If the MOA is active, ATC will issue clearances which insures IFR aircraft avoidance. Routine IFR flight plan/ clearance and IFR communications meet ADIZ requirements / (continued) Charted and identified on both IFR and VFR charts. Charted and identified on both IFR and VFR charts. Identification name and abbreviated “MOA” placed on chart. Air Traffic Control System Structure 159 Charting Charted and identified on VFR charts. Charted and identified on both IFR and VFR charts. VFR Restrictions Pilots operating under VFR are encouraged to contact the radar approach control and avail themselves of the TRSA Services which include traffic advisories and arrival sequencing. However, participation is voluntary on the part of the pilot. VFR operations within, into, or out of an ADIZ is permitted if the pilots file a flight plan, establish and maintain radio communications, and continuously transmit a discrete transponder code assigned by ATC. There may also be additional security equipments established for flights into and out of a domestic ADIZ. IFR Restrictions TRSAs primarily affect VFR flights; therefore, IFR aircraft on an IFR clearance are not affected. Routine IFR flight plan/ clearance and IFR communications meet ADIZ entry requirements. There are additional security equipments established for flights into and out of a domestic ADIZ. Entry Requirements Airspace surrounding designated airports wherein ATC provides radar vectoring, sequencing, and separation on a fulltime basis for all IFR and participating VFR aircraft. No clearance required. After 9/11, a more or less permanent ADIZ was established over the Washington D.C. metropolitan area. At various times, temporary domestic ADIZs have also been delineated. Airspace Description and Use TRSAs were originally established as part of the Terminal Radar Program at selected airports. TRSAs precede the establishment of class C airspace. It was envisioned originally that all TRSAs would be converted to Class C airspace, but some were not. TRSAs do not fit into any of the U.S. airspace classes but continue to be operated where participating pilots can receive additional radar. An ADIZ over U.S. metropolitan areas, which is activated and deactivated as needed, with dimensions, activation dates, and other relevant information disseminated via NOTAM. Airspace Terminal Radar Service Area (TRSA) Domestic ADIZ 160 / CHAPTER 3 Operations on these routes are conducted in accordance with VFR except flight visibility shall be 5 miles or more, and flights shall not be conducted below a ceiling of less than 3,000 feet AGL. IFR yes VFR no Military aircraft operating VFR will operate using VFR rules. IR training routes require an ATC clearance from ATC. MTRs were developed for use by the military for the purpose of conducting low-altitude, high-speed training. The routes above 1,500 feet AGL are developed to be flown, to the maximum extent possible, under IFR. The routes at 1,500 feet AGL and below are generally developed to be flown under VFR. Military Training Routes There are both IFR and VFR MTRs: Listed on aeronautical charts and flight planning publications VFR pilots may select to contact the FSS on the appropriate frequency to receive airport advisory service. Routine IFR flight plan/ clearance and IFR communications permits The FSS provides a complete local airport advisory service, which includes known airport and traffic information to arriving and departing aircraft. Airport advisory service is operated within 10 statute miles of an airport where a control tower is not operating, but where an FSS is located on the airport. AAS is not regulatory airspace. Airport Advisory Service / (continued) VR routes are not depicted on IFR charts although IR charts are. Both VR and IR routes are charted and identified on VFR charts. Identification numbers prefixed with either the letters “IR” or “VR”. Charted and identified on both IFR and VFR charts. Identification numbers prefixed with the letter “A”. VFR flight permitted. All aircraft shall be equally responsible for collision avoidance. IFR flights will be routinely routed through alert areas. IFR aircraft as well as participating aircraft shall be equally responsible for collision avoidance. A clearance is not required to enter an alert area. All flight activity within an alert area is conducted in accordance with FARS. Alert areas are depicted to inform pilots of areas that may contain a high volume of pilot training or an unusual type of aerial activity. Alert Area Air Traffic Control System Structure 161 Pilots are requested to voluntarily avoid flying through the depicted NSA. When it is necessary to provide a greater level of security and safety, flight in NSAs may be temporarily prohibited by regulation. Alert: The purpose of such warning areas is to warn nonparticipating pilots of the potential danger. CFAs contain activities that, if not conducted in a controlled environment, could be hazardous to nonparticipating aircraft. CFA activities are suspended immediately when spotter aircraft, radar, or ground lookout positions indicate an that aircraft might be approaching the area. National security areas are established at locations where there is a requirement for increased security and safety of ground facilities. A warning area is similar to a restricted area, but it is offshore of the United States located in international airspace, and flight cannot be legally restricted. Controlled Firing Area National Security Areas Warning Area Entry Requirements Airspace Description and Use Airspace If the area is active, ATC will issue clearances which ensures IFR aircraft avoidance. If the alert area is not active and has been released, ATC will allow the aircraft to operate in the airspace without issuing specific clearance for it to do so. IFR Restrictions The pilot must contact the controlling agency to determine the areas status. VFR aircraft can legally fly through warning areas. VFR Restrictions Charted and identified on both IFR and VFR charts. Identification numbers prefixed with the letter “W”. There is no need to chart CFAs since they do not cause a nonparticipating aircraft to change its flight path. Charting 162 / CHAPTER 3 Air Traffic Control System Structure / 163 In each class of airspace, both VFR and IFR pilots must comply with the regulations that have been previously mentioned as well as supplemental rules that may apply to flight operations in their specific airspace. In general, Class A is most restrictive, whereas Class G is least. Class A Airspace Class A airspace is generally defined as the airspace extending from 18,000 feet MSL up to and including FL 600, including the airspace overlying the waters within 12 nautical miles off the coast of the forty-eight contiguous states and Alaska as well as the designated international airspace beyond 12 nautical miles off the coast of the forty-eight contiguous states and Alaska within areas of domestic radio navigational signal or ATC radar coverage and within which domestic procedures are applied. Class A airspace is not specifically charted. Class A airspace evolved from the jet advisory areas that were created in the 1960s to provide advisory services to civilian and military turbojet aircraft operating at high altitudes. When the jet advisory areas were first created, they extended from FL 240 to FL 410 and projected 14 nautical miles laterally on either side of every jet route. It was believed that pilots would be unable to “see and avoid” any other VFR or IFR aircraft operating at the same altitude at the high airspeeds at which these aircraft routinely operated. Within jet advisory areas, air traffic controllers were required to use radar to constantly monitor every IFR aircraft operating on a jet route and issue any heading changes (known as vectors) necessary to ensure that the IFR aircraft remained separated from any other aircraft observed on the controller’s radar display. The controllers were not usually in radio contact with the VFR aircraft, so it was impossible to determine their altitude, route of flight, or intentions. Because the actions of these aircraft could not be predicted, the controllers were forced to issue numerous unnecessary vectors to IFR aircraft to ensure that they would remain safely separated. Although this procedure might seem to decrease the probability of midair collisions, in many cases it actually made the situation more dangerous. Since the intentions of the VFR pilots were unknown, it was possible that heading changes could be issued to the IFR pilot at precisely the same moment that the VFR pilot began to maneuver to avoid the collision. This might create a situation even more dangerous than if no heading change had been issued at all. It was soon obvious that unless the controller could be in direct radio contact with every aircraft operating in the vicinity of the jet routes, it would be impossible to positively separate IFR from VFR aircraft. In an attempt to rectify this problem, the FAA has since classified all airspace between 18,000’ and 60,000” MSL as Class A airspace (see Figure 3–9). FAR 91.135 requires that every aircraft operating within Class A airspace operate under instrument flight rules and receive a clearance from ATC. This ATC separation of all aircraft is known as positive control. To operate within Class A airspace, pilots must comply with the following regulations. 164 / CHAPTER 3 Figure 3–9. Class A airspace. Air Traffic Control System Structure FL 600 18,000 MSL / 165 CLASS A 14,500 AGL CLASS E CLASS B CLASS C Nontowered Airport CLASS D 1,200 AGL 700 AGL CLASS G CLASS G CLASS G Figure 3–10. U.S. airspace classifications. • The pilot must be rated for instrument flight. • The aircraft must be operated under instrument flight rules at a route and at an altitude assigned by ATC. • All aircraft must be transponder equipped as specified in FAR 91.215. The creation of this airspace ensured that every aircraft operating at or above 18,000 feet MSL was provided separation services by air traffic controllers. Since the creation of Class A airspace, high-altitude midair collisions have become extremely rare in this country. Figure 3–10 summarizes all the airspace classifications over the United States. Class B Airspace Even though the establishment of Class A airspace virtually eliminated highaltitude midair collisions, as traffic increased around airports, low-altitude collisions began to occur with increasing frequency. The FAA responded by creating a low-altitude version of Class A airspace called a terminal control area (TCA), which has since been reclassified as Class B airspace. Class B airspace is defined as the airspace that extends from the surface of the Earth up to 10,000 feet MSL surrounding the nation’s busiest airports in terms of IFR operations or passenger enplanements. The configuration of each Class B airspace area is individually tailored and consists of a surface area and two or more layers (some Class B airspace areas resemble upside-down wedding cakes) and is designed to contain all published instrument procedures once an aircraft enters the airspace (see Figure 3–11). An ATC clearance is required for all aircraft to operate in the area, and all aircraft that are cleared receive separation services within the airspace. Each successive layer of Class B airspace extends out from the central airport, with the floor of each layer raised to a slightly higher altitude. This 166 / CHAPTER 3 Figure 3–11. Graphic view of Class B airspace and the same airspace as depicted on a sectional chart. Air Traffic Control System Structure / 167 design provides the controller with sufficient airspace to vector aircraft to an instrument approach at the primary airport. The separation procedures applied to aircraft operating within Class B airspace are similar to those applied to aircraft operating in Class A airspace. Prior to entering this airspace, both IFR and VFR pilots are required by FAR 91.131 to receive a clearance from the controlling ATC facility. While operating within the confines of Class B airspace, every pilot is required, if at all possible, to comply with the instructions issued by the controller. Air traffic controllers are responsible for the positive separation of every aircraft within Class B airspace, whether operating under instrument or visual flight rules. This generally means that aircraft operating at the same altitude must be kept at least 3 nautical miles apart. This separation need not be applied if there is at least 1,000 feet of altitude between the aircraft. If either of the aircraft is VFR, the separation can usually be reduced to 1½ miles lateral or 500 feet vertical separation. If both aircraft are VFR or if one is VFR and the other is a small IFR, either 500 feet of vertical separation must be used, or the controller must ensure that the radar targets do not touch. This is known as target resolution. While operating within or, in some cases, near Class B airspace, every pilot must comply with the following FAR 91 regulations: • Every aircraft must be equipped with appropriate communication and navigation radio equipment. This includes a two-way radio transceiver, VOR or TACAN navigation capability, and a transponder. (A transponder permits the controller to positively identify any particular aircraft when using radar for ATC separation. Transponders are discussed in detail in Chapter 8.) • Aircraft may not operate within the airspace underlying Class B airspace at an indicated airspeed greater than 200 knots. • Unless specifically authorized by the controller, every turbine-powered aircraft operating to or from the primary airport must operate above the floor while within the lateral confines of the Class B airspace. • Every aircraft entering Class B airspace or operating within 30 nautical miles of the primary airport must be equipped with a mode C altitude encoder. This device permits the aircraft’s altitude to be shown directly on the controller’s radar display. Pilots operating on IFR flight plans do not need to specifically request permission to enter Class B airspace. VFR pilots, however, must request permission from the ATC facility prior to entering the airspace. Until permission is received from the controller, the VFR pilot is required to remain clear of Class B airspace. IFR aircraft operating within Class B airspace have priority over VFR aircraft. Air traffic controllers are permitted to deny VFR aircraft clearances if conditions are such that, in the opinion of the controller, the entry of the VFR aircraft might compromise safety. These conditions include, but are not limited to, weather, traffic conditions, controller workload, and equipment limitations. However, if the controller concludes that VFR operations can be safely approved, the pilot may be issued a VFR clearance to enter. Upon receiving the clearance, 168 / CHAPTER 3 and after entering, the VFR pilot is required to comply with any instruction issued by the controller but must also observe the basic VFR flight rules. At no time may the VFR pilot disregard VFR flight rules while attempting to comply with a controller’s request. If the pilot believes that the controller’s instructions might cause a violation of any VFR flight rule, the pilot is authorized by FARs 91.3 and 91.123 to disregard that instruction but must inform the controller as soon as feasible. The following terminal areas around the country are currently designated by FAR 71 as Class B airspace: Atlanta, GA Baltimore, MD-Washington, D.C. area Washington Dulles International Airport Washington National Ronald Reagan Airport Baltimore/Washington International Airport Boston, MA Charlotte, NC Chicago O’Hare, IL Cincinnati, OH-(Covington, KY) Cleveland, OH Dallas, TX Dallas/Fort Worth International Airport Dallas Love Field Airport Denver, CO Detroit, MI George Bush Intercontinental/Houston Airport Honolulu, HI Houston, TX John F Kennedy International Airport Kansas City, MO LaGuardia Airport Las Vegas, NV Los Angeles, CA Memphis, TN Miami, FL Minneapolis, MN New Orleans, LA New York, NY-Newark, NJ area Newark Liberty International Airport Orlando, FL Philadelphia, PA Air Traffic Control System Structure / 169 Phoenix, AZ Pittsburgh, PA Saint Louis, MO Salt Lake City, UT San Diego, CA San Francisco, CA Seattle, WA Tampa, FL Washington Dulles International Airport Washington National Ronald Reagen Airport William P. Hobby Airport Class C Airspace Class C airspace was initially implemented in 1984 as airport radar service areas (ARSAs) to provide separation to aircraft flying within the vicinity of medium-sized airports that did not qualify for a TCA. After the airspace reclassification project, ARSAs became Class C airspace. Class C airspace in the United States surrounds medium-activity airports that have the capability to provide ATC services using radar. In general, the Class C airspace is a standard-shaped area that extends from the Earth’s surface, or from an intermediate altitude, up to a higher altitude approximately 4,000 feet above ground level. Within Class C airspace, every aircraft, both IFR and VFR, is subject to the operating rules and pilot and equipment requirements specified in FAR 91. These requirements are similar to, but less restrictive than, the requirements to enter Class A airspace. Student pilot entry into Class A airspace is restricted, whereas student pilots are permitted to operate within Class C airspace under the same rules of operation as any VFR pilot. Class C airspace is defined as the airspace that extends from the surface to 4,000 feet above the airport elevation (charted using MSL) surrounding those airports that have an operational control tower, are serviced by a radar approach control, and have a certain number of IFR operations or passenger enplanements (see Figures 3–12 and 3–13). Although the configuration of each Class C airspace area is individually tailored, the airspace usually consists of a 5-nautical-mile radius core surface area that extends from the surface up to 4,000 feet above the airport elevation and a 10-nautical-mile radius shelf area that extends from 1,200 feet to 4,000 feet above the airport. An outer area extends 20 nautical miles outward from the center of the primary airport and extends from the lower limits of radar/radio coverage up to the ceiling of the approach control’s delegated airspace. Once the aircraft enters Class C airspace, the pilot is required to comply with any instruction issued by the controller but must still comply with the visibility and cloud avoidance requirements of FAR 91. At no time may a VFR pilot disregard the basic VFR rules when trying to comply with the controller’s clearance or subsequent instructions. If the pilot perceives that a controller’s request might force a violation of any of the visual flight rules, the pilot is 170 / CHAPTER 3 Shelf area 10 n mi Height above airport 4,000 ft. Core surface area 5 n mi Outer area 20 n mi Airport 1,200 ft. AGL Services upon establishing two-way radio communication and radar contact; Sequencing arrivals IFR/IFR standard separation IFR/VFR traffic advisories and conflict resolution VFR/VFR traffic advisories Figure 3–12. Depiction of Class C airspace. Figure 3–13. Class C airspace as depicted on a sectional chart. Air Traffic Control System Structure / 171 authorized by FAR 91 to disregard that instruction but must inform the controller as soon as possible. Any VFR or IFR pilot who wishes to enter Class C airspace must comply with the following requirements: • The pilot must establish communications with the appropriate air traffic control facility prior to entering. Unless the pilot is instructed to remain clear, the establishment of communication with the controller authorizes pilot entry into Class C airspace. • While within Class C airspace, the pilot is required to comply with any of the instructions issued by the controller, unless these instructions will cause the pilot to violate a federal regulation, in which case the pilot is authorized to disregard the offending instruction. • The aircraft must be equipped with an operable mode C transponder. The following airports have been established as Class C airspace primary airports: Alabama – Birmingham, Huntsville, Mobile Alaska – Anchorage Arizona – Tucson Arkansas – Little Rock, Fayetteville California – Beale Air Force Base, Burbank, Fresno, Monterey, Oakland International, Ontario, March Air Reserve Base, Sacramento, Santa Barbara, John Wayne Orange County, San José Colorado – Colorado Springs Connecticut – Hartford-Bradley International Florida – Daytona Beach, Fort Lauderdale-Hollywood, Jacksonville, Naval Air Station Whiting Field (South), Naval Air Station Pensacola, Naval Air Station Whiting Field (North), Palm Beach, Pensacola Regional, Southwest FloridaFort Myers, Orlando-Sanford, Sarasota-Bradenton, Tallahassee Georgia – Columbus, Savannah Hawaii – Kahului-Maui Idaho – Boise Illinois – University of Illinois-Champaign-Urbana, Chicago Midway, Quad City-Moline, Greater Peoria, Capital-Springfield Indiana – Evansville, Fort Wayne, Indianapolis, South Bend Iowa – Cedar Rapids, Des Moines Kansas – Wichita Kentucky – Lexington, Louisville-Standiford Louisiana – Barksdale Air Force Base, Baton Rouge, Lafayette, Shreveport Maine – Bangor, Portland Michigan – Flint, Grand Rapids, Lansing Mississippi – Columbus, Air Force Base, Jackson 172 / CHAPTER 3 Missouri – Springfield Montana – Billings Nebraska – Lincoln, Offutt Air Force Base, Omaha Nevada – Reno New Hampshire – Manchester New Jersey – Atlantic City New Mexico – Albuquerque New York – Albany, Buffalo, Long Island MacArthur, Rochester, Syracuse North Carolina – Asheville, Fayetteville, Greensboro-Piedmont Triad, Pope Air Force Base, Raleigh-Durham Ohio – Akron-Canton, Columbus, Dayton, Toledo Oklahoma – Oklahoma City, Tinker Air Force Base, Tulsa Oregon – P