7: Procedures and Airport Operations

Airspace

Chart Supplements U.S.

Notices to Air Missions (NOTAMs)

Communications

Airport Lighting

Airport Marking Aids and Signs

Airport Operation

Wake Turbulence

Flight Plans

Airspace

Controlled airspace, that is, airspace within which some or all aircraft may be subject to air traffic control, consists of those areas designated as Class A, Class B, Class C, Class D, and Class E airspace.

Much of the controlled airspace begins at either 700 feet or 1,200 feet AGL. The lateral limits and floors of Class E airspace of 700 feet are defined by a magenta vignette; while the lateral limits and floors of 1,200 feet are defined by a blue vignette if it abuts uncontrolled airspace. Floors other than 700 feet or 1,200 feet are indicated by a number indicating the floor.

Figure 7-1. Airspace

Class A—Class A airspace extends from 18,000 feet MSL up to and including FL600 and is not depicted on VFR sectional charts. No flight under VFR, including VFR-on-top, is authorized in Class A airspace. Except as provided in 14 CFR §91.135, no person may operate an aircraft within Class A airspace unless it is operated under IFR at a specific flight level assigned by ATC.

Class B—Class B airspace consists of controlled airspace extending upward from the surface or higher, to specified altitudes. Each Class B airspace sector, outlined in blue on the sectional aeronautical chart, is labeled with its delimiting altitudes. On the Terminal Area Chart, each Class B airspace sector is outlined in blue and is labeled with its delimiting arcs, radials, and altitudes. Each Class B airspace location will contain at least one primary airport. An ATC clearance is required prior to operating within Class B airspace. A pilot landing or taking off from one of a group of 12 specific, busy airports must hold at least a Private Pilot Certificate. At other airports, a student pilot may not operate an aircraft on a solo flight within Class B airspace, or to, from, or at an airport located within Class B airspace, unless both ground and flight instruction has been received from an authorized instructor to operate within that Class B airspace or at that airport, and the flight and ground instruction has been received within that Class B airspace or at the specific airport for which the solo flight is authorized. The student’s logbook must be endorsed within the preceding 90 days by the instructor who gave the flight training and the endorsement must specify that the student has been found competent to conduct solo flight operations in that Class B airspace or at that specific airport. Each airplane operating within Class B airspace must be equipped with a two-way radio with appropriate ATC frequencies, and a 4096 code transponder with Mode C automatic altitude-reporting capability. No person may operate an aircraft in Class B airspace unless the aircraft is equipped with the applicable operating transponder and automatic altitude reporting (Mode C) equipment.

Class C—Class C airspace is controlled airspace surrounding designated airports within which ATC provides radar vectoring and sequencing for all IFR and VFR aircraft. Each airplane operating within Class C airspace must be equipped with a two-way radio with appropriate frequencies, and a 4096 Code transponder with Mode C automatic altitude-reporting capability. Communications with ATC must be established prior to entering Class C airspace. Class C airspace consists of two circles, both centered on the primary airport. The surface area has a radius of 5 NM. The airspace of the surface area extends from the surface of Class C airspace airport up to 4,000 feet above that airport, normally. Some situations require different boundaries. The shelf area has a radius of 10 NM. The airspace between the 5 and 10 NM rings begins at a height of 1,200 feet and extends to the same altitude ceiling as the surface area. An outer area with a normal radius of 20 NM surrounds the surface and shelf areas. Within the outer area, pilots are encouraged to participate in ATC communications, but it is not a VFR requirement. Class C airspace service for aircraft proceeding to a satellite airport will be terminated at a sufficient distance to allow time to change to the appropriate tower or advisory frequency. Aircraft departing satellite airports within Class C airspace shall establish two-way communication with ATC as soon as practicable after takeoff. On aeronautical charts, Class C airspace is depicted by solid magenta lines.

No person may operate an aircraft in Class C airspace unless two-way radio communication is established with the ATC facility having jurisdiction over the Class C airspace prior to entering that area, and is thereafter maintained with ATC while within that area. A coded transponder is required for all aircraft in Class C airspace and in all airspace above the ceiling and within the lateral boundaries of Class C airspace upward to 10,000 feet MSL.

Figure 7-2. Class C airspace

Class D—Class D airspace extends upward from the surface to approximately 2,500 feet AGL (the actual height is as needed). Class D airspace may include one or more airports and is normally 4 NM in radius. The actual size and shape is depicted by a blue dashed line and numbers showing the top. When the ceiling of Class D airspace is less than 1,000 feet and/or the visibility is less than 3 SM, pilots wishing to takeoff or land must hold an Instrument Rating, must have filed an instrument flight plan, and must have received an appropriate clearance from ATC. In addition, the aircraft must be equipped for instrument flight. At some locations, a pilot who does not hold an Instrument Rating may be authorized to takeoff or land when the weather is less than that required for visual flight rules. When special VFR flight is prohibited, it will be depicted by “No SVFR” above the airport information on the chart. A turbine-powered airplane or a large airplane shall, unless otherwise required by the applicable distance from cloud criteria, enter the Class D airspace at an altitude of at least 1,500 feet above the surface of the airport and maintain at least 1,500 feet within the airport traffic area, including the traffic pattern, until further descent is required for a safe landing.

Class E—Magenta shading identifies Class E airspace starting at 700 feet AGL, and no shading (or blue if next to Class G airspace) identifies Class E airspace starting at 1,200 feet AGL. It may also start at other altitudes. All airspace from 14,500 feet to 17,999 feet and airspace above 60,000 feet is Class E airspace. It also includes the surface area of some airports with an instrument approach, but no control tower.

Class G—Class G airspace is airspace within which ATC has neither the authority nor responsibility to exercise any control over air traffic.

Aircraft are required to maintain specified cloud clearances and visibilities while in certain airspace. See Figure 7-3.

Figure 7-3. Cloud clearance and visibility requirements in Class E and G airspace

Prohibited Areas are blocks of airspace within which the flight of aircraft is prohibited.

Restricted Areas denote the presence of unusual, often invisible, hazards to aircraft such as artillery firing, aerial gunnery, or guided missiles. Penetration of Restricted Areas without authorization from the using or controlling agency may be extremely hazardous to the aircraft and its occupants.

Warning Areas contain the same hazardous activities as those found in Restricted Areas, but are located in international airspace.

Military Operations Areas (MOAs) consist of airspace established for the purpose of separating certain military training activities from IFR traffic. Pilots operating under VFR should exercise extreme caution while flying within an active MOA. Any FSS within 100 miles of the area will provide information concerning MOA hours of operation. Prior to entering an active MOA, pilots should contact the controlling agency for traffic advisories.

Alert Areas may contain a high volume of pilot training activities or an unusual type of aerial activity, neither of which is hazardous to aircraft. Pilots of participating aircraft, as well as pilots transiting the area, are equally responsible for collision avoidance.

Military Training Routes (MTRs) have been developed for use by the military for the purpose of conducting low-altitude, high-speed training. Generally, MTRs are established below 10,000 feet MSL for operations at speeds in excess of 250 knots.

Chart Supplements U.S.

The Chart Supplements U.S. is a publication designed primarily as a pilot’s operational manual containing all airports, seaplane bases, and heliports open to the public including communications data, navigational facilities, and certain special notices and procedures. Directories are re-issued in their entirety every 56 days.

Runway Gradient

The gradient (upslope or downslope) of a runway is important in determining both the takeoff and landing distance of an airplane. This information is furnished in the Chart Supplements U.S. if it is greater than 0.3 percent (approximately 15 feet in a mile). If no gradient is listed at the end of the line, the gradient is less than 0.3 percent.

Control Tower Operating Hours

The hours of operation of the control tower are shown in the Chart Supplements U.S. under the “Airport Remarks” section. The Z indicates that these times are given in UTC, or Universal Coordinated Time (GMT, or Zulu time). To convert UTC time into local time, use the conversion factor found in the first line about the airport. The symbol ‡ means that when daylight savings time is in effect, the effective times will be one (1) hour earlier.

Information relating to parachute jump areas is contained in 14 CFR Part 105. Tabulations of parachute jump sites in the U.S. are contained in the Chart Supplements U.S.

Notices to Air Missions (NOTAMs)

Notices to Air Missions (NOTAMs) provide the most current information available. They provide time-critical information on airports and changes that affect the national airspace system and are of concern to instrument flight rule (IFR) operations. NOTAM information is classified into five categories: NOTAM (D) or distant, Flight Data Center (FDC) NOTAMs, pointer NOTAMs, Special Activity Airspace (SAA) NOTAMs, and military NOTAMs.

NOTAM (D)s are attached to hourly weather reports and are available at flight service stations (AFSS/FSS). FDC NOTAMs are issued by the National Flight Data Center and contain regulatory information, such as temporary flight restrictions or an amendment to instrument approach procedures.

Pointer NOTAMs highlight or point out another NOTAM such as an FDC or NOTAM (D). This type of NOTAM will assist pilots in cross-referencing important information that may not be found under an airport or NAVAID identifier.

Military NOTAMs pertain to U.S. Air Force, Army, Marine, and Navy NAVAIDs/airports that are part of the NAS.

SAA NOTAMs are issued when Special Activity Airspace will be active outside the published schedule times and when required by the published schedule. Pilots and other users are still responsible to check published schedule times for Special Activity Airspace as well as any NOTAMs for that airspace.

NOTAM (D)s and FDC NOTAMs are contained in the Notices to Air Missions publication, which is issued every 28 days. Prior to any flight, pilots should check for any NOTAMs that could affect their intended flight.

Communications

Automatic Terminal Information Service (ATIS) is the continuous broadcast of recorded non-control information in selected high-activity terminal areas. ATIS information includes the time of the latest weather sequence, ceiling and visibility (if the weather is less than a ceiling of 5,000 feet and a visibility of 5 miles or less), obstructions to visibility, temperature, dew point, wind direction and velocity, altimeter setting, instrument approach and runways in use, and other pertinent remarks. The frequency on which ATIS is transmitted is shown in the information box for the airport on sectional charts and in the communications section of the Chart Supplements U.S. ATIS broadcasts are updated upon the receipt of any official weather, regardless of content changes and reported values. A new recording will also be made when there is a change in other pertinent data, such as runway change, instrument approach in use, etc.

Traffic information will give the location of a target which may constitute traffic for an aircraft that is radar identified. The location is given in azimuth from the aircraft in terms of the 12-hour clock. Traffic at 3 o’clock is off the right wing tip, traffic at 12 o’clock is off the nose, and traffic at 9 o’clock is off the left wing tip. Traffic at 11 o’clock would be between the left wing tip and the nose of the aircraft. Azimuth information given by an air traffic controller is based on the ground track of the aircraft as it is observed. The pilot will have to apply a correction to the reported azimuth if a drift-correction angle is being used to maintain the track.

Under no circumstances should a pilot of a civil aircraft operate the transponder on code 7777. This code is reserved for military interceptor operations. When a pilot is involved in a hijack operation, they should set their transponder code to 7500 to alert ATC.

The universal communications (UNICOM) frequency for an airport with an operating control tower is 122.95 MHz. All inbound traffic should monitor and communicate as appropriate on the designated common traffic advisory frequency (CTAF) from 10 miles to landing. Departing aircraft should monitor/communicate on the appropriate frequency from start-up, during taxi, and until 10 miles from the airport, unless the Federal Aviation Regulations or local procedures require otherwise. “Self-announce” is a procedure whereby pilots broadcast their position, intended flight activity, or ground operations on the designated CTAF. This procedure is used primarily at airports which do not have an FSS on the airport. The self-announcement procedure should also be used if a pilot is unable to communicate with the FSS on the designated CTAF. When there is no tower, FSS, or UNICOM station on the airport, use MULTICOM frequency 122.9 MHz for self-announce procedures. Such airports will be identified in appropriate aeronautical information publications.

If a pilot intends to land at a controlled airport and the radio fails, they should remain outside or above the airport traffic area until the direction and flow of traffic have been determined, then join the airport traffic pattern. If only the transmitter is inoperative, a pilot should monitor the primary local control frequency as depicted on sectional charts for landing or traffic information, and look for a light signal which may be addressed to his/her aircraft. During hours of daylight, pilots should acknowledge tower transmissions or light signals by rocking the wings, and at night, by blinking the landing or navigation lights.

Airport Lighting

The visual approach slope indicator (VASI) is a system of lights so arranged to provide visual descent guidance information during the approach to a runway. These lights are visible from 3 to 5 miles during the day and up to 20 miles or more at night. The visual glide path of the VASI provides safe obstruction clearance within ±10° of the extended runway center line and up to 4 NM from the runway threshold. In a two-bar VASI, the light will be white when you are overshooting the runway and red when you are undershooting it. In order to touch down at the proper position on the runway, you should overshoot the near light and undershoot the far light. When you are on the glide slope, you will see a red light over a white light. As you depart to the high side of the glide slope, the far bars will change from red to pink to white. The lower glide path of a three-bar VASI is provided by the near and middle bars, and is normally set at 3°. The upper glide path, provided by the middle and far bars, is normally 1/4° higher. The upper glide path is intended for use only by high flight deck aircraft, to provide a sufficient threshold crossing height. When you are on the upper glide path, the near and middle bars are white, and the far bar (upper bar) is red.

Figure 7-4. Two-bar VASI

Figure 7-5. Three-bar VASI

The precision approach path indicator (PAPI) uses light units similar to the VASI, but they are installed in a single row of either two or four light units. PAPI has an effective visual range of about 5 miles during the day and up to 20 miles at night. When the aircraft is more than 3.5° high, all the lights will be white; when slightly high, three white and one red; and on glide path, two white and two red. When slightly below (2.8°), one white and three red; and when more than 2.5° low, the pilot will see four red lights.

Figure 7-6. PAPI

Runway edge lights are white, except on instrument runways where amber replaces white on the last 2,000 feet or half of the runway length (whichever is less) to form a caution zone for landings. Runway center line lighting systems in the final 3,000 feet, as viewed from the takeoff or approach position, are used as runway-remaining lights. Alternate red and white lights are seen from the 3,000-foot points to the 1,000-foot points, and all red lights are seen for the last 1,000 feet of the runway.

Military airport beacons flash alternately white and green, but are differentiated from civil beacons by a dual peaked (two quick) white flashes between the green flashes. A rotating beacon that flashes white only is installed on an unlighted land airport. In Class B, C, D, or E airspace, operation of the airport beacon during the hours of daylight often indicates that the weather conditions are below basic VFR minimums. The ground visibility is less than 3 miles, and/or the ceiling is less than 1,000 feet.

Radio control of lighting is available at selected airports, to provide airborne control of lights by keying the aircraft’s microphone. When the microphone is keyed seven times within 5 seconds, the lights are turned on to their highest intensity available (HIRL). When it is keyed times times within 5 seconds, the lights will be turned on to medium or lower intensity (MIRL). When it is keyed three times within 5 seconds, the lights will be turned on the lowest intensity available (LIRL).

Airport Marking Aids and Signs

Runway numbers and letters are determined from the approach direction. The runway number is the whole number nearest one-tenth of the magnetic azimuth of the center line of the runway, measured clockwise from magnetic north. For example, Runway 8 has a magnetic direction of 080°. The other end of this runway is Runway 26, which has a magnetic direction of 260°.

A series of arrows painted along the center line of the approach end of a runway signifies that this portion of the runway is not suitable for landing. These arrows terminate at the displaced threshold marker. This portion of the runway can be used for taxing, for the landing rollout, and for takeoff. See Figure 7-7.

Figure 7-7. Displaced threshold

In Figure 7-8, point B on Runway 12 is the displaced threshold of the runway. This is the beginning of the portion of the runway that is usable for landing. The portion of Runway 12 on which the arrows are painted can be used for taxing and for beginning the takeoff run.

Figure 7-8. Runway markings

Area A on Runway 12 is usable for taxi and takeoff, but it cannot be used for landing. Area E on Runway 30 is a stopway area that appears usable, but which is actually unusable due to the nature of its structure. It can be used only as an overrun.

Taxiway holding lines consist of two continuous and two dashed lines, spaced six inches between lines, perpendicular to the taxiway center line. More recently, hold lines also consist of one or more signs at the edge of the taxiway, with white characters on a red sign face.

When instructed by ATC to “hold short of a runway,” the pilot should stop so that no part of the aircraft extends beyond the holding line. When approaching the holding line from the side with the continuous lines, a pilot should not cross the holding line without ATC clearance at a controlled airport or, at uncontrolled airports, without making sure of adequate separation from other aircraft. An aircraft exiting the runway is not clear until all parts of the aircraft have crossed the holding line. See Figure 7-9.

Figure 7-9. Holding line

A hot spot is a location on an airport movement area with a history or potential risk of collision or runway incursion, and where heightened attention by pilots and drivers is necessary. The FAA depicts hot spots in Chart Supplements with symbols using three shapes with two distinct meanings: a circle or ellipse for ground movement hot spots and a cylinder for wrong-surface hot spots. To address wrong-surface events where an aircraft lines up to or lands on the incorrect runway, taxiway, or airport, the FAA is releasing Arrival Alert Notices (AANs) at several airports with a history of misalignment risk. AANs include graphics that visually depict the approach to a particular airport with a history of misalignment risk and language that describes the misalignment risk. AANs incorporate the standardized hot spot symbology.

Airport Operation

The recommended entry position for an airport traffic pattern is 45° to the midpoint of the downwind leg at traffic pattern altitude. The segmented circle around the wind cone in Figure 7-10 indicates that when landing on Runway 35 you should use a left-hand traffic pattern, when landing on Runway 17, you should use a right-hand pattern, and when landing on Runway 27, you should use a right-hand pattern.

Figure 7-10. Segmented circle and wind cone

Vehicles on the surface of an airport on which a control tower is operating will be controlled by radio or light signals, using the same signals as are used for aircraft on the ground. See Figure 7-11.

Figure 7-11. Light signals

Pilots are encouraged to turn on their landing and position lights any time:

Wake Turbulence

Lift is generated by the creation of a pressure differential over the wing surface. The lowest pressure occurs over the upper wing surface and the highest pressure under the wing. This pressure differential triggers the roll-up of the airflow aft of the wing, resulting in swirling air masses trailing downstream of the wing tips. After the roll-up is completed, the wake consists of two counter-rotating cylindrical vortices. The vortex circulation is outward, upward, and around the wing tips when viewed from either ahead or behind the aircraft.

Since trailing vortices are a by-product of wing lift, wing-tip vortices are generated from the moment an aircraft leaves the ground. Prior to takeoff or touchdown, pilots should note the rotation or touchdown point of the preceding large aircraft. When departing behind a large aircraft, note the large aircraft’s rotation point. Rotate prior to the large aircraft’s rotation point, and continue to climb above and stay upwind of the large aircraft’s climb path until you are able to turn clear of its wake. When landing behind a large aircraft on the same runway, stay at or above the large aircraft’s final approach flight path, note the large aircraft’s touchdown point, and land beyond it.

Flight tests have shown that the vortices from large aircraft sink at a rate of about 400 to 500 feet per minute, and they tend to level off at a distance of about 900 feet below the flight path of the generating aircraft. Vortex strength diminishes with time and distance behind the generating aircraft.

A crosswind will decrease the lateral movement of the upwind vortex and increase the movement of the downwind vortex. Thus a light wind of 3 to 7 knots would result in the upwind vortex remaining in the touchdown zone for a period of time and hasten the drift of the downwind vortex toward another runway. The conditions are the same for an airplane taking off.

Flight Plans

Pilots are encouraged to give their departure times directly to the FSS serving the departure airport, or as otherwise indicated by the FSS when the flight plan is filed. This will ensure more efficient flight plan service and permit the FSS to advise you of significant changes in aeronautical facilities or meteorological conditions. When a VFR flight plan is filed, it will be held by the FSS until 1 hour after the proposed departure time, unless an actual departure time or a revised proposed departure time is received.

A pilot is responsible for ensuring that the VFR or DVFR flight plan is canceled. You should close your flight plan with the nearest FSS, or if one is not available, you may request any ATC facility to relay your cancellation to the FSS. Control towers do not automatically close VFR or DVFR flight plans, since they do not know if a particular VFR aircraft is on a flight plan. If you fail to report or cancel your flight plan within one-half hour after your ETA, search and rescue procedures are started.

[10-2024]