RAF Mildenhall, United Kingdom CNN  — 

As the B-52 Stratofortress approaches from below, the adornments of its cockpit reflect the importance of the day. Next to a Benny the Bull stuffed animal – the Chicago Bulls mascot – lies a Star-Spangled Banner, covering the dashboard from one side to the other. It’s Memorial Day in the United States, one of the country’s most important holidays, but for these airmen, there’s little time for celebration or remembrance.

And at 27,000 feet, somewhere over the edge of the UK, there’s little room for error.

“We were refueling a B-52 that was conducting a NATO op in the NATO airspace,” Captain Todd Berglund explains aboard a KC-135 stratotanker, one of the US Air Force’s air refueling craft. “We pretty much just try to make sure that we’re enabling their mission and they can do whatever they need to do.”

The B-52 Stratofortress displays a US flag as it engages in the NATO exercise on Memorial Day.

The operation can take between 15 minutes and an hour and requires intense coordination between the crew of both aircraft. They both reduce their speed to a mere 316 miles per hour (375 knots) and sync up their movements, allowing a boom to descend from the KC-135 and connect to an opening on the top of the B-52, pumping thousands and thousands of gallons of fuel in minutes.

The complicated endeavor is made to look seamless by these airmen, who have done it many times before. “We do it so often that it just kind of becomes a habit pattern, it’s our profession, it’s just what we do,” says Captain Berglund. “Luckily today it went pretty to plan but it definitely doesn’t always happen that way.”

As the refueling was taking place, two British Royal Air Force (RAF) jets – a Typhoon and a training Hawk 1 – shadowed,the encounter, practicing for when enemy aircraft come into UK airspace.

“They’ll practice a lot of the intercepts so if they need to do it operationally, they know what it’s like coming up if a country’s plane comes into their airspace and how to go about that,” Captain Berglund explained.

Operation “Allied Sky”

Monday’s operation was part of a larger NATO exercise spearheaded by the US Air Force’s bomber task force. Operation “Allied Sky” saw nearly 100 aircraft from 22 NATO member states join up to fly over all the countries that make up the North Atlantic alliance, in a span of 12 hours.

“Bomber missions demonstrate the credibility of our forces to address a global security environment that is more diverse and uncertain than at any other time in our history,” General Jeff Harrigian, commander of NATO Allied Air Command, US Air Forces in Europe and US Air Forces Africa, said of Monday’s exercise. “Today’s mission is an awesome demonstration of NATO air superiority and together there is no challenge we cannot tackle.”

While the interception by RAF aircraft over British skies was merely practice, when the US Air Force flies over parts of Eastern Europe, the Baltic or the Black Sea, it is frequently met by Russian aircraft.

A British RAF Eurofighter Typhoon practices an interception, of the kind regularly experienced in the skies over Eastern Europe.

It’s for moments like those that Captain Berglund and his crew are training.

“Stuff can happen pretty quick, it’s hard to predict how busy the airspace is, how busy the radios are, if other jets are going to be out there,” he says. “It’s really just thinking through all the contingencies in your head, how to make it happen if something changes.”

In the past decade, several encounters with Russian jets have been deemed unsafe by the US military, calling out its Russian counterparts for unprofessional and dangerous actions.

It’s part of a pattern of behavior by both sides that is reminiscent of the Cold War era, when the US and the then Soviet Union would test each other constantly, prodding defenses in search of potential weaknesses.

And while the US is flying its B-52s over Europe, Russia last week deployed three of its Tu-22M bombers to Hmeymim air base in Latakia, Syria. The Tu-22, also known as ‘Backfire,’ has flown over Syria many times in recent years, as Russia stepped in to help President Bashar al-Assad during the country’s civil war. However, in the past they always flew from their bases in Russia.

Aircraft from 22 NATO member states flew over all the countries of the alliance in 12 hours.

Their deployment to Hmeymim is a first, and part of a larger Russian commitment to the region, where it is also investing millions in expanding the Tartus naval base after agreeing a long-term lease with the Syrian government.

If the Russian footprint in the region continues to expand, it could represent a threat to American and NATO forces in the Mediterranean, but also to US allies in the Middle East, such as Israel.

Old but reliable

It’s not just the behavior that harks back to the Cold War, some of the hardware does too. While Russia’s Tu-22M first came into service in 1972, the US Airforce’s B-52s were built in the 50s. The KC-135 came soon after, in 1957. Up close, the signs of aging are easy to spot.

The KC-135’s engines are loud, and from take-off to landing, communication is only possible via state-of-the-art noise canceling headsets. While avionics and sensors have been upgraded, several displays are still analogue and most tasks are still performed manually.

“She’s old but reliable,” says Captain Berglund through the intercom; his crew nods in agreement. “They’re updating it every once in a while, but she’s reliable and it’s working so, no real need to change a whole lot.”

A US Air Force's B-52s were built in the 1950s, as were the KC-135s.

He tells us it “feels good” to pilot the plane, especially considering “all the generations of pilots that have been able to fly it.”

And when it comes to refueling B-52s, the pairing with the KC-135 is a match made in heaven.

“The KC-135 was made for the B-52,” Captain Berglund explained. He said that while the Air Force has begun replacing some of the KC-135s with the new KC-46, the older model is still is expected to remain in service beyond 2040.

For an aircraft built in 1957, that will be close to 100 years.