Four Air Force F-15C Eagles are conducting joint air policing missions with their Bulgarian counterparts from Sept. 9 to 16 -- the first U.S./NATO joint mission in Bulgaria.

The aircraft are from the Massachusetts Air National Guard’s 104th Fighter Wing and the California Air National Guard’s 144th Fighter Wing, attached to the 194th Expeditionary Fighter Squadron, forward deployed to Romania. Some 75 airmen, including active-duty airmen in support roles from the 52nd Fighter Wing at Spangdahlem Air Base, Germany, also traveled to Bulgaria. The Eagles will be flying alongside Bulgarian MiG-29s.

The Bulgarians have become increasingly concerned about Russian incursions into their territory. In July, Bulgaria accused Russian military planes of violating its airspace four times, and civilian planes six times, within the month. Russian officials denied the infringements, but Bulgaria’s defense minister, Nikolay Nenchev, called the events "very worrying."

Though Bulgaria does not share a border with Russia, it's eastern border is on the Black Sea, an area Russia has sought to bring under its sphere of influence. The Russian Federation annexed Crimea in 2014 in the aftermath of the Ukrainian revolution.

The Bulgarian parliament approved the joint air policing mission in February. It "enables on-demand response capabilities, which serve to mitigate and deter violations and infringements on Bulgarian sovereign airspace," according to an Air Force news release.

The Air Force is regularly helping NATO allies defend their airspace, in line with security commitments to NATO.  The 194th EFS previously conducted joint air policing in Iceland in March, the first under the concurrent Operation Atlantic Resolve mission.

Bulgarian MiG29s

Bulgarian MiG-29s at Graf Ignatievo air base will fly joint air policing missions with U.S. Air Force F-15C Eagle fighter aircraft. The U.S. aircraft arrived from Campia Turzii, Romania, where they are part of a theater security package deployment to Europe as a part of Operation Atlantic Resolve.
Photo Credit: SSgt. Joe W. McFadden/Air Force

"It’s important that we are standing side-by-side with our NATO allies," said Lt. Col. Cesar Gonzalez, the 194th Expeditionary Fighter Squadron aircraft maintenance commander, in the news release. "We are committed to the security of Europe and helping Bulgaria and countries who ask for our help.

"Our Guardsmen protect, and we’re on alert protecting the home front and the western front," Gonzalez said. "What a great opportunity to do the same for the Eastern Bloc of Europe."

The air policing mission may increase the likelihood of an unsafe intercept by Russian aircraft, which has been an ongoing concern in recent years. On Sept. 7, a Russian Su-27 flew within 10 feet of a U.S. Navy P-8A over the Black Sea, according to Pentagon officials. Navy Capt. Jeff Davis, a Pentagon spokesman, said the Russian SU-27 Flanker fighter made the unsafe maneuver as the Poseidon aircraft was conducting routine operations in international airspace.

Russian Defense Ministry spokesman Maj. Gen. Igor Konashenkov said in a Sept. 7 statement that the Poseidon aircraft did not have its transponder turned on, and that it approached Russia's southern border twice, but U.S. officials denied that the transponder was turned off .

"We frequently encounter the Russians in and around international airspace," Gen. Frank Gorenc, then-commander of U.S. Air Forces Europe-U.S. Air Forces Africa, told Air Force Times June 27. "The majority of those intercepts continue to be professional, but every once in a while, there is a discussion in respect to the professionalism of a particular crew ... that causes us to look at it and say, ‘What are they doing?' " he said.