Airlines are flying up to 40% longer routes to avoid Russia, with one handing out 'diplomas' to passengers flying over the North Pole

• Airlines are adding up to 40% extra flight time and thousands in extra costs to fly around closed Russian and EU airspace.
• Finland flag carrier Finnair is operating a Cold War-era route that flies over the North Pole, adding four hours.

Airspace closures over Russia and the European Union are forcing airlines to take long detours to avoid restrictions, adding hours of flight time and thousands in extra operating costs.

Shortly after Russia invaded Ukraine on February 24, the EU responded with sweeping sanctions to punish President Vladimir Putin, including closing its airspace to "any plane owned, chartered or otherwise controlled by a Russian legal or natural person."

Russia implemented its own airspace in response, causing havoc for airlines that typically use Russian skies to connect places in Europe and Asia.

With Russian and EU airspace closed, carriers have had to come up with alternate routes to avoid restrictions. For example, Russian national airline Aeroflot added three hours of flight time on a February 27 flight from Serbia to Moscow.

The detours are adding up to 40% of flight time, according to aviation consultancy Ishka, and up to $12,000 per hour in additional costs, aviation consultant Robert Mann told ABC News.

Finland flag carrier Finnair, in particular, is being "severely affected" by Russian airspace closures, Ishka said in its weekly airline report shared with Insider.

While the airline has had to cancel some routes to Asia, the company explained Finnair has committed to continuing flights to key markets on the continent, like Seoul, Shanghai, and Tokyo.

Finnair's continuation of Asia flights, which are potentially unsustainable, is due to the carrier's selling factor of being the "fastest European carrier to Asia," Ishka explained.

On March 9, Finnair operated a flight between Helsinki and Tokyo by flying over the Arctic instead of Russia, adding nearly four hours to the usual nine-hour journey.

Finnair is not the only carrier adding hours of flight time between Europe and Asia. Japan Airlines had an average flight time of 12 hours and 12 minutes between London and Tokyo before Russia invaded Ukraine, but a March 4 flight lasted 14 hours and 50 minutes, according to Flightradar24 data.

Meanwhile, British Airways is adding one hour of time between New Delhi and London by flying south of Russia.

Captain Aleksi Kuosmanen, the deputy fleet chief pilot at Finnair who flies the new route, told CNN that the route typically operates with three pilots, but is now using four.

"We have a specific flight crew bunk where we can sleep and have a rest, and we have also increased the number of meals," he explained.

While some may hate the idea of flying an extra four hours on an already long journey, Kuosmanen told CNN that passengers are responding well.

"I would say that people were enthusiastic," he said. "Many were asking at what time we would be going across the pole and if northern lights were expected."

Moreover, they said the flight is typically not full, so there is plenty of empty rows and cabin space for travelers to spread out.

With the new route, Finnair is turning the long detour into a marketing strategy. On Friday, the airline announced it will be handing out stickers and "diplomas" to passengers who fly the Arctic route over the North Pole.

According to the airline, the company did the same thing back in 1983 when the airline became the first carrier to fly nonstop from Helsinki to Tokyo using the DC-10 trijet.

At the time, most other planes had to stop for fuel in Anchorage, Alaska, but Finnair made the journey by adding extra fuel tanks on board.