Private Pilot · Unit 5 · 30 min

Other Airspace Areas

Lesson goals

By the end of this lesson you will know:

which of the two everyday kinds of NOTAM is regulatory, and why a chart cannot show you most temporary flight restrictions
the three regulations behind the temporary flight restrictions a private pilot most often meets, and the purposes each one serves
what a four-digit military training route number tells you about the altitudes flown on that route
why participation in the radar service of a terminal radar service area is voluntary, and what a national security area asks of you
the difference between a VFR flyway, a VFR corridor, and a Class B VFR transition route
the altitudes, transponder code, and course 14 CFR 93.95 prescribes in the Los Angeles Special Flight Rules Area, and what a VFR flight into an air defense identification zone requires

The fourth type of airspace

This unit opened by dividing the National Airspace System into four types: controlled airspace, uncontrolled airspace, special use airspace, and other airspace. This lesson covers the fourth.

Other airspace areas is a general term referring to the majority of the remaining airspace (PHAK Chapter 15). The term carries no operating rules of its own. PHAK's list under it runs to fourteen items:

Local Airport Advisory;
military training routes (MTRs);
temporary flight restrictions (TFRs);
parachute jump aircraft operations;
published VFR routes;
terminal radar service areas (TRSAs);
national security areas (NSAs);
air defense identification zones (ADIZ) over land and water, and the Defense VFR (DVFR) flight plan needed to fly VFR in one;
interception procedures, and the use of 121.5 MHz when not already talking to air traffic control (ATC);
the Flight Restricted Zone near the Capitol and the White House;
the special awareness training 14 CFR 91.161 requires for VFR flight within 60 nautical miles of the Washington, DC VOR/DME navigation station (identifier DCA);
wildlife areas, wilderness areas, and national parks, over which flight above 2,000 feet above the surface is requested;
National Oceanic and Atmospheric Administration marine areas off the coast, which carry a requirement to operate above 2,000 feet above the surface rather than a request;
tethered balloons for observation and weather recording, which extend on cables up to 60,000 feet.

Local Airport Advisory is a service available only in Alaska, provided within 10 statute miles of an airport where no control tower is operating but where a flight service station (FSS) is located on the airport (AIM 3-5-1). Parachute jump aircraft operations are governed by 14 CFR part 105 and are tabulated in the Chart Supplement. Sites used frequently are depicted on sectional charts, and the jump pilot announces the operation on the common traffic advisory frequency (PHAK Chapter 15; AIM 3-5-4). A tethered balloon is an obstruction to look up on the chart. Two further areas appear on no chart at all. A stationary or moving altitude reservation is announced by an airspace NOTAM, and a nonparticipating VFR flight is permitted to fly through it. ATC assigned airspace segregates the activity inside it from other IFR traffic. Its schedule appears on the FAA special use airspace website, and no NOTAM announces its activation (AIM 3-5-10). Interception procedures and the operating procedures inside the Washington, DC area are not taught in this course, though the 14 CFR 91.161 training requirement is, later in this lesson.

PHAK Ch 15, "Other Airspace Areas," "Local Airport Advisory (LAA)," and "Parachute Jump Aircraft Operations"; AIM 3-5-1, 3-5-4, 3-5-10; 14 CFR part 105

The NOTAM system

The Notice to Airmen (NOTAM) system provides pilots with time critical aeronautical information that is temporary, or information to be published on aeronautical charts at a later date, or information from another operational publication (AIM 5-1-3). A NOTAM is cancelled when its information reaches the chart or when the temporary condition returns to normal status. Each pilot in command must, before beginning a flight, become familiar with all available information concerning that flight (14 CFR 91.103), and NOTAM information is part of what is available (AIM 5-1-3).

Of the four classifications the system uses, two appear routinely in a private pilot's briefing:

A NOTAM D is disseminated for every navigational facility that is part of the National Airspace System and for every public use aerodrome, seaplane base, and heliport listed in the Chart Supplement. Its subjects are aerodrome conditions, airspace activity, navigational aids, and communications, and each one carries a keyword such as RWY or SVC after the location identifier (AIM 5-1-3).
An FDC NOTAM, issued by the Flight Data Center, is used when it is necessary to disseminate regulatory information. Amendments to published instrument approach procedures and to current aeronautical charts arrive this way, and so do temporary flight restrictions (AIM 5-1-3).

Regulatory means the notice itself carries the force of a rule. With one exception covered below, a temporary flight restriction has no charted boundary to look up and no altitude printed in any margin; the text of the NOTAM defines it entirely.

The chart excerpt of P-40 in the previous lesson carried a printed CAUTION box directing you to contact Flight Service for the latest flight restriction status and NOTAMs associated with that area. Retrieving NOTAMs, choosing a briefing, and decoding the contractions they are written in belong to Unit 8.

AIM 5-1-3; 14 CFR 91.103; PHAK Ch 15, "Temporary Flight Restrictions (TFR)"

Temporary flight restrictions

A temporary flight restriction is a volume of airspace, designated by an FDC NOTAM, inside which flight is restricted for a stated reason and a stated period (PHAK Chapter 15). The NOTAM opens with the phrase FLIGHT RESTRICTIONS and then gives the location, the effective period, the area in statute miles, the altitudes affected, the FAA coordination facility, and the reason.

Three regulations create the restrictions a private pilot most often meets. Under 14 CFR 91.137(a), the Administrator will issue a NOTAM designating an area within which temporary flight restrictions apply and specifying the hazard or condition requiring their imposition, on determining that it is necessary in order to:

protect persons and property on the surface or in the air from a hazard associated with an incident on the surface (14 CFR 91.137(a)(1));
provide a safe environment for the operation of disaster relief aircraft (14 CFR 91.137(a)(2));
prevent an unsafe congestion of sightseeing and other aircraft above an incident or event which may generate a high degree of public interest (14 CFR 91.137(a)(3)).

What is prohibited then depends on which purpose the NOTAM was issued under. Issued to protect persons and property from a surface hazard, it admits no transit: no person may operate an aircraft in the designated area unless that aircraft is participating in the hazard relief activities, under the direction of the official in charge of on scene emergency response activities (14 CFR 91.137(b)). Issued for disaster relief or for an event drawing sightseers, it permits a short list of operations, among them flight under an ATC approved IFR flight plan (14 CFR 91.137(c), 91.137(d)).

The second regulation is one sentence. No person may operate an aircraft over or in the vicinity of any area to be visited or traveled by the President, the Vice President, or other public figures contrary to the restrictions established by the Administrator and published in a NOTAM (14 CFR 91.141). The restriction moves with the visit.

The third covers gatherings. The FAA will issue a NOTAM designating an area of airspace in which a temporary flight restriction applies in the vicinity of an aerial demonstration or major sporting event (14 CFR 91.145(a)). The airspace is normally limited to a 5 nautical mile radius and 17,000 feet MSL for a demonstration by high performance aircraft, and to a 3 nautical mile radius and 2,500 feet above the surface for a sporting event (14 CFR 91.145(e)). The NOTAM is issued at least 30 days in advance unless the FAA finds good cause for a shorter period (14 CFR 91.145(f)).

Two further regulations designate a temporary flight restriction the same way. 14 CFR 91.138 covers a declared national disaster area in the State of Hawaii, and 14 CFR 91.143 covers space flight operations (AIM 3-5-3).

Most TFRs appear on no chart Only temporary flight restrictions relating to national security are charted, drawn with a broken blue line (FAA Aeronautical Chart Users' Guide). Every other one exists solely as text in an FDC NOTAM, so a current sectional chart is silent about the wildfire, the presidential visit, or the airshow along your route. Incursions have cost pilots security investigations and certificate suspensions (PHAK Chapter 15).

One restriction near Los Angeles is neither temporary nor a TFR. It is charted as a Special Security Notice Permanent Continuous Flight Restriction Area: a blue circle on the map face with a boxed note beside it (FAA Aeronautical Chart Users' Guide).

A blue-outlined note box printed on a sectional chart. The heading reads DISNEYLAND THEME PARK, and the text below reads: Pursuant to Public Law 108-199, Section 521, aircraft flight operations are prohibited at and below 3000 feet AGL within a 3 nautical mile radius of the Disneyland Theme Park (334805N/1175517W or the Seal Beach (SLI) VORTAC 066 degree radial at 6.8 nautical miles) except as specified. See Supplement for details. — The boxed note that goes with the charted circle over Anaheim, California. Its authority is a statute rather than a part of 14 CFR: Public Law 108-199, Section 521. The note gives the volume, locates the center twice, and sends you to the Chart Supplement for the exceptions. Los Angeles Sectional Aeronautical Chart, effective 9 July 2026 (FAA), cropped.

14 CFR 91.137, 91.138, 91.141, 91.143, 91.145; PHAK Ch 15, "Temporary Flight Restrictions (TFR)"; AIM 3-5-3; FAA Aeronautical Chart Users' Guide, "Other Airspace Areas"

Military training routes

A military training route is a route developed jointly by the FAA and the Department of Defense for low-altitude, high-speed military training (AIM 3-5-2). Routes are generally established below 10,000 feet MSL for operations at speeds in excess of 250 knots, and a segment may be defined higher for route continuity, for a descent, for a climbout, or over mountainous terrain (PHAK Chapter 15; AIM 3-5-2).

Each route is identified by two letters and a number. The letters give the flight rules. Operations on an IR route are conducted in accordance with IFR regardless of weather conditions. Operations on a VR route are conducted in accordance with VFR, except that flight visibility must be 5 miles or more and the flight must not be conducted below a ceiling of less than 3,000 feet AGL (AIM 3-5-2).

A route with no segment above 1,500 feet AGL is identified by four number characters, as in VR1207. A route with one or more segments above 1,500 feet AGL is identified by three, as in IR206 (PHAK Chapter 15; AIM 3-5-2). On the chart the designator is printed in solid black on the route centerline, with small arrowheads beside it for the direction of flight (FAA Aeronautical Chart Users' Guide).

Sectional chart excerpt of the Mojave Desert. A thin gray line runs left to right across the upper part of the frame, carrying a solid black leftward arrowhead followed by the designator VR1218 in solid black type. Below it the words BARSTOW MOA are printed in large magenta capitals. — VR1218 crossing the Mojave Desert, in the same excerpt the previous lesson used for the Barstow military operations area boundary. The gray line is the route centerline, the arrowhead beside the designator gives the direction of flight, and the four digits mean no segment lies above 1,500 feet above the ground. Los Angeles Sectional Aeronautical Chart, effective 9 July 2026 (FAA), cropped.

The centerline is not the route Route width varies for each military training route and can extend several miles on either side of the charted centerline (AIM 3-5-2). The actual width, the altitudes in use on each segment, and the times of scheduled activity are held by Flight Service, and a pilot in flight can request them from any flight service station within 100 nautical miles of the route.

No regulation prohibits a nonparticipating aircraft from flying within a military training route (AIM 3-5-2). What the route tells you is where to expect a fast airplane at low altitude. Your own 250 knot limit below 10,000 feet MSL under 14 CFR 91.117(a) stays in force while that traffic exceeds it, and your duty to see and avoid other aircraft under 14 CFR 91.113(b) is unchanged.

14 CFR 91.117(a), 91.113(b); PHAK Ch 15, "Military Training Routes (MTRs)"; AIM 3-5-2; FAA Aeronautical Chart Users' Guide, "Other Airspace Areas"

Terminal radar service areas

A terminal radar service area is an area where participating pilots can receive additional radar services. The purpose of the service is to provide separation between all IFR operations and participating VFR aircraft (PHAK Chapter 15).

Establishing a TRSA was never subject to the rulemaking process, so TRSAs appear nowhere in 14 CFR part 71, there are no TRSA operating rules in 14 CFR part 91, and a TRSA does not fit into any of the United States airspace classes (AIM 3-5-6).

The primary airport or airports within a TRSA become Class D airspace, and the remaining portion overlies other controlled airspace, normally Class E airspace beginning at 700 or 1,200 feet (PHAK Chapter 15). Entering the Class D core requires two-way radio communications, as it does anywhere. Entering the rest of the TRSA requires no clearance and no radio call. Participation is voluntary, and pilots operating under VFR are encouraged to contact the radar approach control and take advantage of the service (AIM 3-5-6). The service itself, and the call that asks for it, come with radio communications in Unit 6.

The chart draws a TRSA in gray: the outer limit a continuous screened black line, the sectors inside it narrower screened black lines, each sector's altitudes printed in solid black as the MSL ceiling above the MSL floor with the last two zeros removed, and the name near the north position of the area (FAA Aeronautical Chart Users' Guide). The Class D portion keeps its own blue segmented line (PHAK Chapter 15).

Sectional chart excerpt of the Coachella Valley in California. A thick gray arc curves down the left side of the frame, with a blue dashed line inside it around the city area. The figures 100 above SFC are printed in large solid black type over the yellow city tint, and a blue box with dashed corners contains the figure 30. Blue type reads PALM SPRINGS INTL (PSP), CT 119.7. — The Palm Springs terminal radar service area, drawn as the thick gray arc, with the Class D core inside it on its own blue dashed line. The black 100 over SFC gives that sector's limits, surface up to 10,000 feet MSL. The 30 in the dashed blue box is a different number: the Class D ceiling, 3,000 feet MSL, printed in hundreds of feet. Los Angeles Sectional Aeronautical Chart, effective 9 July 2026 (FAA), cropped.

PHAK Ch 15, "Terminal Radar Service Areas (TRSAs)"; AIM 3-5-6; FAA Aeronautical Chart Users' Guide, "Other Airspace Areas"

National security areas

A national security area consists of airspace of defined vertical and lateral dimensions established at a location where there is a requirement for increased security and safety of ground facilities. Pilots are requested to voluntarily avoid flying through a depicted NSA (AIM 3-4-8).

When it is necessary to provide a greater level of security and safety, flight in an NSA may be temporarily prohibited by regulation under the provisions of 14 CFR 99.7, and the prohibition is disseminated by NOTAM (AIM 3-4-8). That section requires each person operating an aircraft in an ADIZ or a Defense Area to comply with special security instructions issued by the Administrator in the interest of national security. Until such a NOTAM exists, no regulation keeps you out.

The chart draws the boundary as a broken magenta line, and an area too small to outline as a small solid magenta shape (FAA Aeronautical Chart Users' Guide).

Sectional chart excerpt east of Livermore, California. A small solid magenta shape sits in the upper left of the frame, with a magenta dotted leader line running from it down to a magenta-outlined box. The box reads, in magenta capitals: NOTICE, FOR REASONS OF NATIONAL SECURITY PILOTS ARE REQUESTED TO AVOID FLIGHT AT AND BELOW 800 feet AGL IN THIS AREA. At the right a small blue polygon whose inward hatch ticks fill its whole interior carries the designation R-2531. — A national security area small enough that the chart prints it as a solid magenta shape rather than an outline, with a magenta leader line tying it to its NOTICE box. The box's wording is a request; nothing in it is a prohibition. The blue hatched polygon at the right is restricted area R-2531, small enough that the hatch ticks from its edges fill it. Entering it between its designated altitudes and during its hours of designation requires the authorization the previous lesson covered. San Francisco Sectional Aeronautical Chart, effective 9 July 2026 (FAA), cropped.

AIM 3-4-8; 14 CFR 99.7; PHAK Ch 15, "National Security Areas (NSAs)"; FAA Aeronautical Chart Users' Guide, "Other Airspace Areas"

Published VFR routes

Published VFR routes exist for transitioning around, under, and through complex airspace such as Class B airspace (AIM 3-5-5). Three are named on charts, and they differ in whether ATC has to authorize you.

A VFR flyway is a general flight path, not defined as a specific course, for use by pilots in planning flights into, out of, through, or near complex terminal airspace so as to avoid Class B airspace. An ATC clearance is not required to fly one. Flyways are depicted on the reverse side of some VFR Terminal Area Charts (AIM 3-5-5).
A VFR corridor is airspace through Class B airspace, with defined vertical and lateral boundaries, in which aircraft may operate without an ATC clearance or communication with air traffic control. A corridor is surrounded on all sides by Class B airspace and does not extend down to the surface (AIM 3-5-5). Few were ever built.
A Class B VFR transition route is a specific flight course depicted and described on a Terminal Area Chart or a VFR Flyway Planning Chart. Communication with ATC is required where the route transitions Class B, Class C, or Class D airspace, and a clearance is required in addition to operate in the Class B airspace itself. Until ATC authorization is received, you must remain clear of the Class B airspace (AIM 3-5-5).

A flyway keeps you outside the Class B airspace, so the Class B clearance requirement of 14 CFR 91.131(a)(1) never arises. A corridor passes through the Class B airspace inside boundaries where no clearance is required (AIM 3-5-5). A transition route goes through the Class B airspace itself, which is why it needs the clearance that airspace has always needed. On initial contact for one, give ATC your position, your altitude, the route name you want, and your direction of flight (AIM 3-5-5).

Sectional chart excerpt over the Los Angeles basin on a pale blue Class B tint. A magenta-outlined box in magenta capitals reads: SEE LOS ANGELES TERMINAL AREA CHART FOR COASTAL, HOLLYWOOD PARK, COLISEUM AND MINI VFR TRANSITION ROUTES. Below it a blue-outlined box reads: VFR Traffic ops within the limits of V 27 in the LOS ANGELES CLASS B AIRSPACE CTC SOCAL APP ON 134.9. — The four transition routes named in the magenta box are each drawn and described on the Los Angeles Terminal Area Chart rather than here. The blue box beneath instructs VFR traffic within the limits of V 27 in the Los Angeles Class B airspace to contact SoCal Approach on 134.9. Los Angeles Sectional Aeronautical Chart, effective 9 July 2026 (FAA), cropped.

AIM 3-5-5; PHAK Ch 15, "Published VFR Routes"; FAA Aeronautical Chart Users' Guide, "Airspace Information"

Special flight rules areas

14 CFR part 93 prescribes special air traffic rules for aircraft operating within the boundaries of certain designated airspace, and the procedures, operations, size, and traffic density vary among the areas it names (AIM 3-5-7).

A special flight rules area (SFRA) is airspace of defined dimensions, above land areas or territorial waters, within which the flight of aircraft is subject to the rules set forth in 14 CFR part 93, unless otherwise authorized by air traffic control. Not every area listed in part 93 is designated an SFRA, but special air traffic rules apply to all of them (AIM 3-5-7). The chart marks a part 93 airport by boxing the airport's name and draws an SFRA boundary with its own blue symbol (FAA Aeronautical Chart Users' Guide).

Reading one of these areas means reading its subpart, because each subpart is written for one place. Subpart G is the Los Angeles Special Flight Rules Area. Its rules prescribe one course over the ground, two altitudes, and one transponder code.

Sectional chart excerpt over the Los Angeles basin on a pale blue Class B tint. A magenta-outlined box printed in magenta reads, on six lines: LOS ANGELES, SPECIAL FLIGHT RULES AREA, 3500 feet and 4500 feet MSL, Refer to current Los Angeles VFR Terminal Area Chart for additional user requirements. Pale blue airway bands labeled V 107, V 299, and V 25 cross the frame. — The Los Angeles Special Flight Rules Area on the sectional, which gives the two altitudes and then sends you elsewhere. The printed figures are the two levels 14 CFR 93.95 designates, and the note sends you to the current Los Angeles VFR Terminal Area Chart for the additional user requirements. Los Angeles Sectional Aeronautical Chart, effective 9 July 2026 (FAA), cropped.

Subpart G prescribes special air traffic rules for aircraft conducting VFR operations in the Los Angeles Special Flight Rules Area (14 CFR 93.91). The area is that part of Area A of the Los Angeles Class B airspace area at 3,500 feet MSL and at 4,500 feet MSL, bounded by Ballona Creek, Manchester Boulevard, the 405 Freeway, Imperial Highway, and the Pacific shoreline (14 CFR 93.93). The area exists only at those two altitudes over that boundary; it is not a continuous block from 3,500 to 4,500 feet MSL.

Unless otherwise authorized by the Administrator, no person may operate an aircraft in that airspace unless the operation is conducted in accordance with the procedures of 14 CFR 93.95. They are:

the flight is conducted under VFR, and only when it can be conducted in compliance with the basic VFR minimums of 14 CFR 91.155(a) (14 CFR 93.95(a));
the aircraft is equipped as specified in 14 CFR 91.215(b), replying on code 1201 before entering and while inside the area (14 CFR 93.95(b));
the pilot has a current Los Angeles Terminal Area Chart in the aircraft (14 CFR 93.95(c));
the pilot operates on the Santa Monica VOR 132 degree radial (14 CFR 93.95(d));
aircraft navigating in a southeasterly direction are in level flight at 3,500 feet MSL (14 CFR 93.95(e));
aircraft navigating in a northwesterly direction are in level flight at 4,500 feet MSL (14 CFR 93.95(f));
indicated airspeed does not exceed 140 knots (14 CFR 93.95(g));
anti-collision lights and position lights are on, and use of landing lights is recommended (14 CFR 93.95(h));
turbojet aircraft are prohibited from VFR operations in the area (14 CFR 93.95(i)).

14 CFR 91.215(b) is the transponder requirement already covered earlier in this unit, and what 93.95(b) adds is the code it replies on. Code 1201 identifies you to the controllers working the traffic above and below as an airplane complying with these rules.

The navigation item names a radial, which is a magnetic bearing extending outward from a navigation station. Holding the 132 degree radial of the Santa Monica VOR puts every airplane in the area on one line over the ground, and the two directions of flight are separated by the 1,000 feet between the levels. Navigating by VOR radials is the subject of Unit 10.

Notwithstanding 14 CFR 91.131(a), an ATC authorization is not required in the Los Angeles Special Flight Rules Area for operations in compliance with 14 CFR 93.95, and all other provisions of 14 CFR 91.131 apply (14 CFR 93.97).

The area drawn in elevation. Everything the subpart designates lies in the two bands, both on one radial and both squawking one code. Above and below them the Class B airspace is ordinary Class B airspace, where 14 CFR 91.131(a)(1) requires a clearance. The Los Angeles Class B airspace here runs from the surface to 10,000 feet MSL, which the sectional prints as 100 over SFC.

Subpart O prescribes a special air traffic rule for VFR operations in the vicinity of Luke Air Force Base, Arizona, and it prescribes no altitude, code, or course: before operating within the Luke Terminal Area a pilot establishes radio contact with the Luke radar approach control (RAPCON), and maintains two-way radio communication with that facility or an appropriate ATC facility while inside, unless otherwise authorized by ATC (14 CFR 93.175, 93.177(a)). The chart carries that requirement as a boxed note giving the frequency, 118.15 for Luke Approach Control.

Subpart V designates the Washington, DC Metropolitan Area Special Flight Rules Area, the airspace from the surface to but not including flight level 180 within a 30 mile radius of the DCA VOR/DME, which contains the Washington, DC Metropolitan Area Flight Restricted Zone (14 CFR 93.335). One requirement reaches further than the special flight rules area itself does: except as provided in 14 CFR 91.161(e), no person may serve as pilot in command or as second in command of an aircraft while flying within a 60 nautical mile radius of the DCA VOR/DME, under VFR, unless that pilot has completed Special Awareness Training and holds a certificate of training completion (14 CFR 91.161(a)). The training is free on the FAA website (14 CFR 91.161(b)).

14 CFR 93.91, 93.93, 93.95, 93.97, 93.175, 93.177, 93.335, 91.161, 91.215(b), 91.131; AIM 3-5-7, 3-5-8; FAA Aeronautical Chart Users' Guide, "Other Airspace Areas"

Air defense identification zones

An air defense identification zone is an area of airspace over land or water in which the ready identification, location, and control of all aircraft is required in the interest of national security, excepting Department of Defense and law enforcement aircraft (14 CFR 99.3). Zones are designated in subpart B of part 99, and the contiguous United States ADIZ is described there as one continuous line enclosing a band off the Atlantic, Gulf, and Pacific coasts (14 CFR 99.43).

Defense visual flight rules means a flight within an ADIZ conducted in accordance with the visual flight rules of part 91 (14 CFR 99.3). Three requirements attach to such a flight, and none of them is a weather minimum.

A radio and a listening watch. A person who operates a civil aircraft into an ADIZ must have a functioning two-way radio, and the pilot must maintain a continuous listening watch on the appropriate aeronautical facility's frequency (14 CFR 99.9(a)). An aeronautical facility means a communications facility where flight plans or position reports are normally filed during flight operations (14 CFR 99.3).
A DVFR flight plan, filed, activated, and closed. No person may operate an aircraft into, within, or from a departure point within an ADIZ unless the person files, activates, and closes a flight plan with the appropriate aeronautical facility, or is otherwise authorized by ATC (14 CFR 99.11(a)). A flight plan for VFR flight is designated a DVFR flight plan (14 CFR 99.11(c)). It contains the time and point of ADIZ penetration, and the aircraft must depart within five minutes of the estimated departure time it contains (14 CFR 99.9(b)).
A transponder with altitude reporting. Unless otherwise authorized by ATC, each aircraft conducting operations into, within, or across the contiguous United States ADIZ must be equipped with an operable radar beacon transponder, turned on, replying on a discrete code assigned by ATC or issued by a flight service station, and displaying the aircraft altitude. Code 1200 is not authorized (AIM 5-6-4). The regulation behind that instruction applies to a civil aircraft operating into or out of the United States into, within, or across the contiguous U.S. ADIZ, and it requires a coded radar beacon transponder with automatic pressure altitude reporting equipment that replies to interrogations by transmitting pressure altitude in 100-foot increments (14 CFR 99.13(c)).

A DVFR flight also reports its position before crossing: the time, position, and altitude at the last reporting point before penetration with an estimate for the next one, or, where the route has no appropriate reporting point, the estimated time, position, and altitude of penetration at least 15 minutes beforehand (14 CFR 99.15(b)).

The requirements above are all in subpart A of part 99. Except for 14 CFR 99.7, 99.13, and 99.15, that subpart does not apply to a flight within the 48 contiguous States and the District of Columbia, or within the State of Alaska, that remains within 10 nautical miles of its point of departure (14 CFR 99.1(b)(1)).

Sectional chart excerpt over the Pacific Ocean on a pale blue tint with no land in the frame. A band of magenta dots runs from the upper left to the lower right beside a thin solid magenta line, with the words CONTIGUOUS U.S. ADIZ lettered in large magenta capitals along it. Above the band a heavy blue line made of rectangular blocks curves across the frame, labeled 1200 AGL, and at the lower right two blue lines each carrying a band of long thin ticks cross one another. — The boundary symbol for an air defense identification zone: a band of magenta dots with the zone lettered along it (FAA Aeronautical Chart Users' Guide). This stretch lies over the Pacific Ocean west of the Southern California coast, where the boundary described in 14 CFR 99.43 runs well offshore. The blocked blue line labeled 1200 AGL marks a change in the floor of the overlying controlled airspace. Los Angeles Sectional Aeronautical Chart, effective 9 July 2026 (FAA), cropped.

14 CFR 99.1, 99.3, 99.7, 99.9, 99.11, 99.13, 99.15, 99.43; AIM 5-6-3, 5-6-4; FAA Aeronautical Chart Users' Guide, "Other Airspace Areas"

What this unit has covered

This unit has now covered all four types of airspace: the controlled classes with the equipment and communication each requires, uncontrolled airspace, the six kinds of special use airspace, and the other airspace areas in this lesson. It has also covered the VFR weather minimums that apply in each class.

Unit 6 takes the airport and the chart themselves: the traffic pattern, runway markings and lighting, the radio calls that establish the communications this unit kept requiring, and a full reading of the sectional.

Why this matters in the airplane

Four of the areas in this lesson change what a preflight has to produce.

Only temporary flight restrictions relating to national security are charted, so the NOTAMs for the route are the only place a wildfire restriction or a presidential visit appears.
A military training route marks where a military airplane may be flying above 250 knots at low altitude while 14 CFR 91.117(a) holds you to 250 knots indicated below 10,000 feet MSL. A four-digit identifier puts every segment of the route at or below 1,500 feet above the ground. The route can extend several miles on either side of the charted centerline, and Flight Service holds the actual width.
A terminal radar service area asks nothing of you outside its Class D core, and a radio call to approach control gets you the radar service inside it.
In the Los Angeles Special Flight Rules Area, compliance with 14 CFR 93.95 takes the place of a Class B clearance (14 CFR 93.97). Fly it at 3,500 feet MSL southeast-bound or 4,500 feet MSL northwest-bound, on the Santa Monica VOR 132 degree radial, squawking 1201, at 140 knots or less, and no one has to clear you into Class B airspace. Miss any one of those and you are in Class B airspace without a clearance.

Check your understanding

Answer from memory, without scrolling back up. Recalling it yourself is what makes it stick.

A temporary flight restriction is designated by which of these?

Which regulation restricts flight in the vicinity of the President?

The military training route VR1218 has four digits, which tells you?

Operations on an IR military training route are conducted how?

Participation in the radar service inside a terminal radar service area is?

Inside a charted national security area, a pilot is?

Which published VFR route requires a clearance to operate in Class B?

Flying southeastward in the Los Angeles Special Flight Rules Area, you are?

Flying VFR within 60 nautical miles of the DCA VOR/DME requires?

Flying VFR into the contiguous United States ADIZ requires which set?

Go deeper (primary source): read 14 CFR part 93 subpart G end to end and count how many of the nine procedures in 93.95 you could comply with in the airplane you are training in. Then read AIM Section 3-5 from 3-5-1 through 3-5-10 and mark which paragraphs cite a regulation and which only describe a service.

Stuck or curious? Ask your instructor to pull up the NOTAMs for a cross-country route you have flown, and to point out which entries would have changed the flight and which were noise. Then ask whether they have flown a special flight rules area or a published VFR transition route, and what they had ready in the cockpit before they entered it.

Course home Glossary