Airlines are adding hours of extra flight time and taking on higher fuel and labor costs to avoid closed airspace

• Russian and EU airspace closures have forced airlines to take alternate routes, adding extra time and operating costs.
• British Airways added one hour of flight time from India to London, while Aeroflot added three hours from Serbia to Moscow.

Airspace closures over Russia and the European Union have forced airlines to come up with alternate routes to avoid restrictions, and it's adding hours of flight time and thousands in extra operating costs.

On Sunday, the EU closed its airspace to "any plane owned, chartered or otherwise controlled by a Russian legal or natural person" as part of sweeping sanctions to punish Russian President Vladimir Putin. Russia responded with its own restrictions shortly after.

Russian flag carrier Aeroflot was one of the first airlines to feel the impact of airspace closures. On Sunday, the airline took off on a flight from Belgrade, Serbia, to Moscow that typically flies north across Eastern Europe to its destination in Russia.

However, due to the EU's newly imposed airspace restrictions, the plane had to fly around Bulgaria and across Turkey to get to Russian airspace, according to data from FlightRadar24. The detour put the flight time at five hours and 45 minutes — three hours longer than the usual two and a half hour flight.

Meanwhile, Sydney-based Qantas has changed its flight path from Australia to London by flying over the Middle East and Southern Europe instead of Russia. Furthermore, British Airways has adjusted its route from New Delhi to London, adding one hour to the flight time.

While US carriers do not fly to airports in Russia or Ukraine, they have had to adjust some of their routings in the region. United Airlines told employees on Tuesday that it will stop using Russian airspace on flights to and from India, reported The Points Guy.

According to analysts, the detours are ramping up the cost of fuel, labor, and maintenance, which could lead to an increase in passenger fares and cargo rates. New York-based aviation consultant Robert Mann told ABC News that rerouted passenger planes could cost airlines $4,000 to $12,000 extra per hour.

For example, German carrier Lufthansa's cargo division said it has to carry up to 20% less freight due to the longer flight time, The Wall Street Journal reported. Currently, the carrier is avoiding Russian airspace by flying south of the country.

"Some routings will simply become uneconomic or impractical," Mann explained.

Instead of rerouting, some carriers have opted to suspend flights instead. London-based Virgin Atlantic Airways temporarily axed cargo service between London and Shanghai, Finnair stopped flights to airports in Japan, China, and South Korea, and Singapore Airlines ended service to Moscow, according to WSJ.

Airspace closures could also impact aircraft lessors that need to repossess aircraft stranded in Russia. On Sunday, the EU required aircraft leasing companies to cancel their contracts with Russian airlines by March 28, meaning those planes will need to be returned to their foreign owners.

However, Russian carriers and the nation's government could impose obstacles to make the task a logistical nightmare.

"It's possible the government could choose to challenge the lessors' abilities to repossess these planes, claiming Aeroflot is not doing any harm by operating the aircraft domestically," Henry Harteveldt, analyst and president of Atmosphere Research Group, told Insider.

"Who is going to fly these airplanes from Russia? How do the airlines get their Russian pilots back home again?" he continued. "All the logistics have to be figured out."