Aviation Training Consultants: 800-874-5346
Aviation Training Consultants: 800-874-5346

Southern Florida ADIZ Flying to the Dry Tortugas

Flight Training > Southern Florida ADIZ Flying to the Dry Tortugas

Over the New Year’s holiday, I flew to Key West, Florida, which is an awesome destination if you are looking for fun places to fly in south Florida. Warm weather in the 80s and warm water greeted us while the rest of the United States which was experiencing average temperatures around 30-40°F. After a weekend of jet skiing, parasailing. SCUBA diving, and sunset cruises, not to mention experiencing Duval Street on New Year’s Eve, it was time to head home to central Florida.

One of the more interesting sights near Key West we wanted to visit on the return flight was the Dry Tortugas, an archipelago of seven small islands about 60 NM West of Key West. The Dry Tortugas is now a national park, but in the 1500s it was a navigation point for the Spanish gold and silver trade. In the 19th century, once Florida become part of the U.S., it was deemed an ideal location for fort to protect the sea lanes around the Florida gulf coast.

Today there are daily seaplane and boat tours to the islands for visitors to explore, hike, picnic, or snorkel around Fort Jefferson. While there is no airfield located on the islands, Fort Jefferson and the shallow waters around the fort seemed like an interesting destination to overfly on the way home from Key West.

Since the Dry Tortugas are U.S. territory and we couldn’t land there, I thought we could fly directly there and back to the west coast of Florida. Discussing the flight with FBO personnel at Signature in Key West brought some new “requirements” to light I hadn’t considered. A review of the chart as part of pre-flight planning shows the following airspace:

  1. Departing from Key West, we would begin in Class D airspace.
  2. Heading west from Key West, we would enter Class E airspace starting at 700 ft. AGL (magenta airbrushed area).
  3. Further west, we would need to be at or above 2,000 ft. AGL as we would enter the Key West National Wildlife Refuge (blue solid line with adjacent blue dots).
  4. Continuing west, we would transition through the ADIZ (Air Defense Identification Zone) and into warning area W-174E.

W-174E is controlled by Miami Center. We would be on flight following with ATC, so they would let us know if the Warning Area was “hot” (in use by the military for live firing) or “cold” (not being used).

But is there any issues with transitioning through the ADIZ?

What do we need to do to transition in/out of the ADIZ properly? Since we are leaving U.S. airspace (sort of), is any special flight plan required? Do we need to clear Customs on the way back in? It was time for some research.

Air Defense Identification Zone (ADIZ)

All aircraft entering U.S. domestic airspace from points outside must provide for identification prior to entry or exit. ADIZs have been established to assist in early identification of aircraft in the vicinity of international U.S. airspace boundaries (AIM Section 6, 5-6-1).

Many aircraft inbound to the U.S. will cross an ADIZ. There is no ADIZ between the U.S. and Canada. According to FAR Part 99, if penetrating an ADIZ, all aircraft of U.S. or foreign registry must file, activate, and close a flight plan with the appropriate aeronautical facility. In addition to normal ADIZ position reports, and any other reports Air Traffic Control may require, a foreign civil aircraft must give a position report at least one hour before ADIZ penetration, if it is not more than two hours average cruising speed from the U.S.

For Defense VFR (DVFR) flights, the estimated time of ADIZ penetration must be filed with the appropriate aeronautical facility at least 15 minutes before penetration, except for flights in the Alaskan ADIZ, in which case, report prior to penetration. Additionally, VFR pilots must receive and transmit a discrete transponder code.

Be sure to activate your flight plan before crossing the ADIZ.

Lets see what NORAD has to say:

After reviewing the FAA regulations, it appears that I would need to file a DVFR flight plan with FSS. The time of our return flight back inbound through the ADIZ had to be calculated and filed with the DVFR flight plan in the REMARKS block. You can use the NORAD table above to calculate.

We used VFR flight following with ATC the whole time so that they were aware of our position in real time. When we filed the DFVR flight plan, we obtained a discrete Customs and Border Protection Transponder code that we squawked on departure for ATC.

Next, I needed to figure out if I needed to clear  U.S. Customs at an airport of entry if I departed from the U.S., never landed, and returned as part of the same flight.

Airport of Entry

From the U.S. Customs and Border Protection (CBP) website: “All civil, private aircraft entering the U.S. must first land at an airport of entry before continuing to their destinations, unless other arrangements are made with U.S. CBP. Advance notification must be provided electronically to CBP by means of the eAPIS. See the APIS section for more information.

Customs will expect aircraft to land at the arrival time entered on their flight plan. Arriving up to 10 minutes late is acceptable. Passengers and crew should remain with the aircraft until a Customs official arrives and be prepared to show valid documents for persons and aircraft.

Some aircraft arriving from foreign locations south of the United States must land for Customs processing at the nearest airport to the border or coastline crossing point, unless an overflight exemption has been granted (CFR Title 19, 122.24).”

From our research on the CBP website and FAA websites, if your aircraft originates in the U.S., never lands at a foreign destination airport, and returns to the U.S. without landing, there is no requirement to clear Customs or file (see below).

“Additionally, private aircraft APIS regulations do not apply to overflights of foreign airspace, provided the private aircraft departs and arrives in the U.S. and does not land at a foreign port (or overflights of U.S. airspace that do not include a U.S. arrival or departure).”


Flights into and out of the U.S. that penetrate an ADIZ are possible and easy to do.

  • You will need to file a DVFR flight plan with your arrival time and location in the REMARKS section of the plan.
  • You will need to contact ATC and notify them of the pre-assigned transponder squawk code you received from FSS when you filed your DVFR flight plan.
  • Fly the route.
  • Notify ATC when you are 15 minutes from penetrating the INNER boundary of the ADIZ.
  • Then continue on your pre-planned flight.

Hope that this was helpful! Contact us with questions or additional topics you would like to see Gleim discuss.

Related Posts