Crossing Skies: From Korea to Japan

Part 1: Seoul to Tsushima

In September 2024, with the dedicated support of Mr. Fujise from Kitakyushu, we accomplished what had never been done in the history of general aviation between Korea and Japan: a round-trip flight from Seoul’s Gimpo Airport to Tsushima Airport.

Legally speaking, Tsushima is designated as a domestic-only airport in Japan, not an international one. Yet, every time I flew between Gimpo and Kitakyushu and passed above the island, I couldn’t help but wonder: What would it be like to land there?

Tsushima lies only about 230 miles from Gimpo. It’s close enough that, in a continent like Europe where cross-border flying is far more open, I’d consider flying there weekly to enjoy fishing and sake. Just as Europe has realized its dream of a shared airspace under “One Sky,” I began dreaming of “One Sky in Asia” — or perhaps, more realistically, “One Sky for Korea–Japan.”

With cautious hope, I started calling the relevant offices on Tsushima. To my surprise, the responses weren’t entirely discouraging:

• Airport Authority: “If customs, immigration, and quarantine (CIQ) can be arranged, the airport has no issue.”
• Customs: “We’ll consider it.”
• Immigration: “If Customs approves, we’re good.”
• Quarantine: No clear answer: they seemed to be waiting on the others.

Encouraged, we sent formal letters on behalf of AOPA Korea and waited. Responses didn’t come immediately, but follow-up calls revealed something important: discussions were underway behind the scenes, and the mood had shifted from tentative to positive. Soon, the Fukuoka Immigration Bureau sent us the official form for a “Temporary International Port Opening Application,” followed by similar forms from other agencies.

That was the turning point. For the first time in history, a general aviation aircraft flew internationally from Korea to Tsushima and back!

The route had changed since my previous cross-border flights. In the past, airspace transitions occurred at the INVOK and APELA waypoints. Now, a new waypoint, BESNA, had been added, with Daegu and Kobe control centers handling transitions for Korea and Japan respectively.

It seems that an agreement between the two air traffic centers required a climb to 12,000 feet approaching BESNA. However, and despite that instruction, I successfully negotiated to remain at 10,000 feet, on this occasion. Soon, Tsushima appeared through the haze.

Crossing into Japanese airspace, I noticed the switch in radio accents: Korea’s “Konglish” became Japan’s “Janglish.” Familiar, but still quirky, although these differences are part of the fun.

The downside of this arrangement is that from 10,000 feet, we needed to descend to 3,000 feet to overfly the airport, fast. This meant a descent of more than 1,400 feet per minute for over 5 minutes. For the pilot in me, this was manageable, but as a mechanic, it’s painful: rapid cooling would risk cylinder cracks in the Malibu’s engine. At least our ears were comfortable, thanks to the Malibu’s cabin pressurization.

The route across the strait via the new BESNA waypoint, where control passes from Daegu to Kobe, down to Tsushima (VCE).

Once safely on the ground, AOPA Korea’s Vice President Nam, who is deeply schooled in humanities and history (unlike me, a science guy), suggested a visit to the northern tip of Tsushima. We drove to the historic sites of the Russo-Japanese War and gained a deeper appreciation of the island’s strategic legacy.

We also made a delicious discovery: a local sake from a countryside sushi shop. The first sip revealed something exceptional, confirmed by quick research to be an award-winning brand, well-known across Japan. That, and a fantastic ramen shop near the hotel, gave me yet another reason, however flimsy, to return to Tsushima. Chalk up another great experience for general aviation!

The next day, everything was in place: CIQ officers were waiting, as promised. I went to the airport office to fax our flight plan, only to find an unexpected email from Japan’s Civil Aviation Bureau: “You’ve landed at an airport not designated for international flights. Approval is required, even retroactively.”

I called Tokyo. They seemed as stunned as I was. No precedent, no clear protocol. But I’d been through worse. I knew we weren’t going to court just for this.

Right there, I grabbed my laptop and wrote a humble note, admitting ignorance and promising to study the regulations carefully in future. I submitted the required entry form (which technically should have been filed 10 days earlier), then pleaded to allow our already-waiting CIQ officers to proceed. Eventually, we received permission to depart.

In situations like this, I have found that finding a way for officials to gracefully exit is usually advisable, and the apology letter served that purpose well.

This flight taught me more than any manual or memo could. From CIQ logistics to the peculiarities of Tsushima’s jurisdiction, it was an unforgettable lesson in navigating international procedures from the cockpit.

The CIQ officers, who were deployed from a local port office, had waited an hour without knowing what was going on. I don’t blame them if they felt frustrated as well.

Fast forward to May 2025. We attempted the route again, this time continuing on to Kumamoto. Thanks to our previous efforts, Japan’s Civil Aviation Bureau, airport authorities, and CIQ staff remembered us. This time, entry felt routine. Cross-border GA flights to Tsushima were becoming a recognized practice.

To maintain that hard-earned trust, I realized, we would need to return regularly, not just for practice, but for the sake of building something lasting.

Part 2: Beyond Borders, from Tsushima to Kumamoto and Back to Seoul

The AOPA Korea group outside the terminal at Tsushima Airport.

By May 2025, we had a much clearer understanding of the rules. According to Japan’s Civil Aviation Bureau, international flights between designated international airports don’t require advance authorization, just pre-coordination with the destination airport and prior permission, and filing a flight plan. It sounded simple enough.

We had already proven that a general aviation flight from Korea to Tsushima was possible. This time, we wanted to take it a step further: to continue from Tsushima on to Kumamoto. The concept was to use Tsushima as a gateway into Japan’s domestic airspace. If we could successfully change the status of our international flight to a domestic flight at Tsushima, our foreign-registered aircraft would be reclassified as eligible to operate domestically, allowing us to continue our flights freely within Japan.

This status change for domestic flight is critical. It refers to a customs and regulatory reclassification that allows a foreign aircraft to be treated like a Japanese-registered aircraft while operating within the country. Without it, an aircraft remains under international status, regardless of where you’ve cleared customs, immigration, and quarantine (CIQ).

At Tsushima, we completed CIQ without issue, but for some reason, the status change for domestic flight wasn’t processed. We were told to continue flying to Kumamoto under international aircraft status and complete customs procedures there. That seemed manageable, at least then.

When we landed at Kumamoto, we parked at the general aviation “Papa Ramp”, not the international terminal, and submitted our General Declaration (GD) form. But when we approached customs with Mr. Sinnaga, we realized things weren’t that simple.

Because the status change for domestic flight hadn’t been completed at Tsushima, our aircraft was still officially international. The Papa Ramp, although on the same airfield, lies outside the jurisdiction of customs and immigration. So technically, we had landed a foreign aircraft at a location not approved for international entry. Even something as small as carrying a personal bag off the aircraft now required special documentation.

It was nobody’s fault — just a classic case of the rules not matching the reality on the ground. Still, it felt absurd.

Fortunately, thanks to Mr. Sinnaga’s tireless coordination with customs and airport officials, we were able to resolve the situation. But the next challenge was just around the corner: how could we legally depart from Japan as a foreign-status aircraft that was parked in a domestic-only area?

After two days of discussions, a clever solution was reached:

1. The crew would board the aircraft and taxi to the international stand for a temporary one-hour stop.
2. Customs officers would meet us there and escort us to the immigration building.
3. Exit procedures would be completed, including passport stamps and customs clearance.
4. After submitting the GD, we would be escorted back to the aircraft for departure.

And it worked! We filed a VFR plan via Iki (IKE) and Tsushima (VCE), then re-entered Korean airspace. The flight back to Seoul was peaceful and uneventful — a welcome contrast to the procedural gauntlet we had just passed through.

Afterward, Mr. Sinnaga shared a promising idea born from this experience: GA aircraft arriving internationally should first park at the international terminal to complete CIQ and the status change for domestic flight, and only then move to the general aviation ramp. It’s simple, logical, and could prevent future pilots from falling into the same trap.

He invited us to come back and test this improved system. I found myself genuinely wanting to, not just for the sake of it, but because returning would mean I’d helped shape the system for the better for the future.

The flight track from Gimpo (GMP) to Kumamoto. Map © 2025 FlightAware, © OpenStreetMap contributors.

The Root of the Problem: Fuel Taxation

Reflecting on the root of the problem, it came down to one issue: fuel taxation.

In Japan, the status change for domestic flight is under the authority of customs, primarily so they can assess and apply domestic tax on any remaining fuel, which they assume will be consumed within the country. It’s a reasonable policy for airliners or large cargo ships, but for small GA aircraft like ours, it feels needlessly burdensome. A few liters of fuel shouldn’t trigger a full customs review.

I began researching other countries, including the U.S., Canada, and EU nations to see if they have similar fuel tax rules. I haven’t found any. That’s why I believe both AOPA Korea and AOPA Japan should work together to:

• Abolish fuel tax rules that hinder GA freedom of movement.
• Streamline the status change for domestic flight so it can be handled instantly on arrival.

In the end, I didn’t feel frustrated or annoyed. If anything, I felt more connected — to the region, the people, and the system we’re helping shape. The more I fly to Kyushu, the more it feels like a nearby town rather than a foreign country.