Airspace Avoidance Routing: Russia, Belarus and the New Long-Haul Geometry
A London to Tokyo great circle goes straight over Siberia. The flight does not. Since 2022, a meaningful share of long-haul routing has been shaped less by geography than by which regions of airspace are actually overflyable. Great Circle Pro now models that explicitly with an Airspace toggle on the Flight Plan tool that detours each route around restricted regions and updates block time, fuel, range check, and emissions accordingly.
The Map and the Territory
A great circle is a geometric ideal. It assumes the aircraft can pass through any longitude, any latitude, any point on the sphere with no permission required. That assumption used to be roughly true for most of the world. In 2026 it is roughly false for a long list of regions, and the gap between what the geometry says and what the schedule actually files has grown to two or three hours on the affected routes.
A British Airways 787 from Heathrow to Tokyo Haneda files a 14 hour 30 minute block. The London to Tokyo great-circle distance is 5,178 nautical miles, which at the airframe's long-range cruise should burn about 11 hours of air time plus taxi padding. The two and a half hour gap is not aerodynamic. It is the extra arc the flight has to fly to stay clear of Russian and Belarusian airspace, plus the headwind penalty along the longer track. Same pair, same airframe, twice the routing.
Why this matters for planning. A model that knows winds but not routes will mis-time every long-haul leg that touches restricted airspace. LHR to HND, DEL to JFK, LHR to HKG, the entire Europe-to-East-Asia bank: the geometric ideal is no longer the operational reality, and a planner who treats the great circle as truth will be hours off filed block. Airspace avoidance closes that gap.
What is Actually Restricted
The 2026 landscape, sourced from EASA Conflict Zone Information Bulletins (CZIBs) and FAA Special Federal Aviation Regulations (SFARs):
- Russia (West and Far East). Closed to US, EU, UK, Canada, Japan, and Korea carriers since February 2022. This is the single biggest distortion in long-haul routing today.
- Belarus. Closed since 2021 after the Ryanair forced-landing incident. Compounds with Russia for many trans-Eurasian routings.
- Ukraine FIR. Active conflict, blanket avoidance since February 2022.
- Syria. Active conflict zone, EASA advisory since 2014.
- Libya. US carriers banned under FAA SFAR 112.
- Yemen Sanaa FIR. Missile activity since 2024.
- Sudan. Civil war since April 2023.
- North Korea. Total avoid under FAA SFAR 91, in force since 2003.
- Afghanistan. FAA SFAR 91 plus EASA CZIB-2021-15 since August 2021.
- Iran (partial sectors). Selective restrictions for US carriers under SFAR 91.
These ten entries are the live working set as of mid-2026. The list moves slowly: most of the entries have been in effect for years, and the recent additions (Sudan, Yemen) trace to specific conflicts with public effective dates. Each entry is recorded with its source bulletin and the date the restriction took effect.
What Happens When You Turn the Toggle On
With Airspace avoidance on, a route that would otherwise cross a restricted region routes around it instead. Where a real-world airline routing is known for that city pair, the tool uses that filed routing, so the shape matches how the leg is actually flown; for pairs without a known routing it draws an efficient estimate that stays a safe margin clear of the closure. Either way you can compare the detour side by side against the plain great circle on the route card, so the cost of the closure is explicit. The tool also handles the common compound cases (Russia plus Belarus on Europe-to-East-Asia, Russia plus Iran sectors on US-East-Coast-to-South-Asia) so the user does not have to think through which regions the route happens to skirt.
The detoured distance, not the great-circle haversine, feeds the block time, fuel, range check, and emissions on the Flight Plan card. So a route that picks up several hundred nautical miles of detour also picks up the proportional extra fuel burn, the proportional extra CO2, and the proportional knock on whether the airframe can still make the mission. The detour is highlighted on the route card with an amber chip listing the regions avoided and the distance added.
Try it. Plot LHR to HND with a 787-9. With Airspace off, the great circle reads 5,178 nm and 11 hours air time, the route arcs directly over Russia. With Airspace on, the route bends south through Caspian airspace, the distance jumps to about 5,750 nm, the block time gains roughly an hour, and the route card surfaces an amber "Routed around RU + BY airspace" badge.
Where the Data Comes From
The list is curated against the authoritative regulatory sources:
- EASA Conflict Zone Information Bulletins (CZIBs). Issued by the European Union Aviation Safety Agency. Each bulletin names a country or region, summarises the safety concern, and carries a review timeline. The EASA CZIB index is the closest thing the industry has to a single public source of truth for "do not fly here" advisories.
- FAA Special Federal Aviation Regulations (SFARs). Published in the United States Federal Register. SFAR 91 covers North Korea, SFAR 112 covers Iran and Libya, and there are several other airspace-specific SFARs. They are binding for US-certified operators.
Each entry carries a source reference and an effective-from date. For operational dispatch use, refer to current NOTAMs and your operator's published procedures.
Maintenance
Airspace closures change. Not often, but they change. The Russia closure is now four years old and shows no sign of lifting; the Sudan civil war is one year old and could shift either way. The list is reviewed quarterly against the EASA CZIB index and the FAA SFAR list. If a new bulletin appears, an entry is added; if an existing bulletin is cancelled, the entry is retired. Retired entries are tracked separately so older saved planning artefacts continue to render with the geometry they were built against.
Where to Use This
Both toggles default to off. The reason is that a long-term planning tool needs to be able to answer both questions: what does the geographic ideal look like, and what does the operational reality look like? The Off-by-default great circle is the geographic ideal. The On state is the operational reality as of 2026-Q3. Both are useful, and the user gets to pick.
A few specific use cases where toggling On matters:
- Block time validation. If your tool predicts 11 hours for LHR to HND and the airline schedule says 14 hours, the gap is real-world routing, not a wind-model defect. Turn airspace avoidance on and the gap closes.
- Fuel and CO2 estimates. The detoured distance is what burns fuel and emits carbon. Block fuel and emissions calculations consume the detoured nm directly, so toggling on gives you the right number on the first read.
- Scenario modelling. If you want to plan against a future where current closures are lifted, leave the toggle off. The geometric ideal becomes the operating geometry.
The Off-state map matches every Great Circle Pro share link that predates this feature, so existing routes you have shared with colleagues will continue to render exactly as before. The On-state is purely additive: a new capability for users who want it, with no surprises for users who do not.