5.4 Other Airspace, TFRs, TRSA, ADIZ, and SFRA

AIM Chapter 3, Section 5 collects the airspace that is not a class and not classic SUA. ACS PA.I.E.K3 groups TFRs, SFRAs, and “other airspace areas” with SUA because they all change what you may do on a VFR cross-country. The common error is to memorize one radius and apply it everywhere. Stadiums are not Mode C veils. The DC SFRA is not Class B. A TRSA is not Class C.

Temporary flight restrictions

AIM 3-5-3 and 14 CFR 91.137–91.143 describe why the FAA draws a temporary keep-out or keep-away. You comply with the NOTAM text, not with a memory of last year’s football game. Check FDC and local NOTAMs during preflight and again if the flight is long.

The stadium figure is a classic mix-up. Covered events are generally professional baseball and football, NCAA Division I football, and major motor-speedway events at venues with a seating capacity of 30,000 or more. The 30,000 is seats. The 30 NM figure in this chapter belongs to the Mode C veil and to the approximate DC SFRA radius, not to the stadium ring. The standing security TFR that PAR has tested for years is 3 nautical miles from the stadium, surface to 3,000 feet AGL, from one hour before the scheduled start until one hour after the event ends. FAA Order language for requested major-event TFRs sometimes uses a 3 NM / 2,500 AGL planning template; the NOTAM in effect for that date is always the legal document. Do not invent a 30 NM stadium cylinder.

VIP TFRs under 91.141 can be much larger than 3 NM and can include an inner prohibited-like ring and an outer identification ring. Space TFRs under 91.143 can also be tens of miles across. Read the FDC. “All TFRs are 3 NM / 3,000 AGL” is as wrong as “stadiums are 30 NM.”

TRSA — optional radar, Class D core

AIM 3-5-6: a Terminal Radar Service Area is not a part 71 airspace class and has no part 91 operating rule of its own. The primary airport is Class D. The rest of the TRSA usually overlies Class E that begins at 700 or 1,200 feet AGL. Charts use a solid black line with segment altitudes. VFR pilots are encouraged to contact approach and use TRSA service. Participation is voluntary. That is the opposite of Class B (clearance) and Class C (required communications inside the Charlie). If you decline TRSA service you still must obey the underlying Class D communications rule near the tower.

ADIZ — DVFR, not “just a VFR flight plan”

An Air Defense Identification Zone surrounds the United States for security identification of inbound aircraft. 14 CFR 99.11: no person may operate into, within, or from a departure point within an ADIZ unless that person files, activates, and closes a flight plan (unless an exception in part 99 applies). AIM 5-6: VFR traffic files a Defense VFR (DVFR) flight plan that includes the time and point of ADIZ penetration, activates it with Flight Service, and squawks the assigned discrete code before entry. An ordinary airborne VFR flight plan that was never filed as DVFR is how pilots get intercepted. Depart within the part 99 time tolerance of the estimated departure time (AIM cites 5 minutes). IFR aircraft already on an IFR plan meet the flight-plan half; they still comply with the ADIZ identification procedures. DoD and law-enforcement exceptions exist; your 172 rental does not inherit them.

DC SFRA and FRZ — still in effect

14 CFR part 93 subpart V (current through 2026) still designates the Washington, DC, Metropolitan Area Special Flight Rules Area and the inner Flight Restricted Zone. FAA’s public description remains a roughly 30 NM SFRA around DCA surrounding an approximately 15 NM FRZ. AIM 3-5-7 and 3-5-8 send you to 93.339, not to “Class B procedures only.”

93.339, at a PAR level: before operating in the DC SFRA, including the FRZ, a typical civil VFR flight needs an operable two-way radio, two-way communications with the appropriate ATC facility, an operating altitude-reporting transponder, a discrete transponder code (93.339(e) forbids 1200 in the SFRA), and a DC SFRA or DC FRZ flight plan that is activated by obtaining that discrete code. A Class B clearance is still required to enter the Washington Tri-Area Class B. Class D inside the SFRA still requires 91.129 communications. The FRZ is more restrictive than the outer SFRA: the three small Maryland/Virginia airports inside the FRZ operate under TSA/FAA security procedures, and a random VFR sight-seeing cut across downtown is not a legal plan. Traffic-pattern-only work at nontower SFRA airports outside the FRZ has its own 93.339(c) checklist (pattern flight plan, CTAF, discrete code, monitor 121.5 if equipped).

SFRAs and special air traffic rules also exist elsewhere under part 93 (Los Angeles, Grand Canyon, and others). If the sectional shows an SFRA boundary, open part 93 or the Chart Supplement procedure for that area. Do not assume every SFRA is a copy of Washington.

Military training routes, wilderness, and airport advisory

AIM 3-5-2: IR routes are flown IFR; VR routes are flown VFR with at least 5 miles visibility and not below a 3,000-foot AGL ceiling. A route with no segment above 1,500 feet AGL uses four digits (VR1207). A route with any segment above 1,500 feet AGL uses three digits (VR207). You may fly through an MTR; use extreme vigilance and ask FSS within 100 NM for scheduled times, altitudes, and the actual width — the corridor can extend miles either side of the thin gray line.

Over charted national parks, wilderness areas, and wildlife refuges, FAA requests (AC 91-36 / AIM noise-sensitive-area guidance) that you maintain 2,000 feet AGL. That is not a 91.119 minimum-safe-altitude rewrite and it is not a TFR. 91.119 still governs hard legal floors (1,000 feet above the highest obstacle in a congested area, 500 feet from any person/vessel/vehicle/structure in uncongested areas, or the emergency/landing exception). Buzzing a national park at 500 feet can be legal under 91.119 and still reckless and contrary to the requested 2,000-foot overflight.

Local Airport Advisory (AIM 3-5-1) is now an Alaska FSS product within 10 statute miles of an airport where the FSS is on the field and the tower is closed. Participation is not mandatory. Remote Airport Information Service appears by NOTAM for short events. Do not expect an LAA frequency at a Lower-48 nontowered strip.

PAR scenario: Saturday you plan a VFR hop that passes a 70,000-seat football stadium at 2,500 feet AGL, 2 NM from midfield, kickoff in 20 minutes. The standing stadium TFR is in effect. You are inside 3 NM and below 3,000 AGL. Divert. The same day you also file an ordinary VFR flight plan for a coastal hop that will cross the ADIZ inbound from the Bahamas. That VFR plan is the wrong flavor — file DVFR, activate it, and squawk the discrete code before the ADIZ line. Two different “other airspace” problems, two different fixes, neither of which is “Class E 3 SM and 152.”