More than 150 U.S. and Bulgarian air force members volunteered free time to clean up two parks in the community here April 22.

Second Lt. Bryan Humphries, 31st Maintenance Squadron, cleans playground equipment at a park in Graf Ignatievo, Bulgaria April 22, 2012. More than 150 U.S. and Bulgarian air force members volunteered their off-duty time to refurbish playground equipment and build a soccer field at a village park. U.S. Air Force members are deployed from the 31st Fighter Wing at Aviano Air Base, Italy, to Graf Ignatievo Air Force Base to participate in Thracian Star 2012, a coalition training exercise geared towards strengthening partnerships and improving interoperability between NATO allies.

U.S. Air Force members rake and clean debris from a soccer field April 22, 2012, in Graf Ignatievo, Bulgaria. More than 150 U.S. and Bulgarian air force members volunteered their off-duty time to refurbish playground equipment and build a soccer field at a village playground. Volunteers cleaned and painted playground equipment and raked, supplied new goals, cleaned and laid grass seed down in a field. U.S. Air Force members are deployed from the 31st Fighter Wing at Aviano Air Base, Italy, to Graf Ignatievo Air Force Base in support of Thracian Star 2012, a bilateral coalition training exercise geared towards strengthening partnerships and improving interoperability between NATO allies.

U.S. and Bulgarian Airmen launched Thracian Star 2012, a joint training exercise focused on building partnerships and increasing interoperability, during a ceremony here April 18.

GRAF IGNATIEVO AIR FORCE BASE, Bulgaria -- Col. David Walker, 31st Operations Group and Thracian Star 2012 detachment commander, speaks to a journalist from the Bulgarian Telegraph Agency through a translator April 18, 2012 during the opening ceremony for the month-long joint training exercise focused on building partnerships and increasing interoperability with the Bulgarian air force. Bulgarian and American senior officials took the opportunity to acknowledge and express appreciation for the long-standing partnership between the two nations.

GRAF IGNATIEVO AIR FORCE BASE, Bulgaria -- Maj. Metodi Orlov, (left), a Bulgarian air force MiG-29 pilot, welcomes Maj. Matthew Brockhaus, (right), an F-16 pilot deployed with the 555th Fighter Squadron out of Aviano Air Base, Italy, to Bulgaria on April 17, 2012. Brockhaus is one of more than 500 U.S. Airmen taking part in Thracian Star 2012, a month-long joint training exercise focused on building partnerships and increasing interoperability with the Bulgarian air force. This is the third time since 2007 that men and women from the 31st Fighter Wing out of Aviano AB have conducted this type of training with the Bulgarians.

Staff Sgt. David Ambrusko, 31st Logistics Readiness Squadron fuels service controller, refuels an F-16 after landing at Graf Ignatievo Air Force Base April 17, 2012. Graf Ignatievo is now host to more than two dozen F-16 Fighting Falcons and more than 500 U.S. Air Force personnel in support of Thracian Star 2012, a month-long joint training exercise focused on building partnerships and increasing interoperability with the Bulgarian pilots, maintainers, joint terminal air controllers, firefighters and security forces Airmen.

Tech. Sgt. Brent Watkins, Airman Gage Boardingham and Airman 1st Class Corey Loesch, 31st Civil Engineer Squadron firefighters, test a barrier engagement on an F-16 after landing at Graf Ignatievo Air Force Base April 17, 2012. Graf Ignatievo is now host to more than two dozen F-16 Fighting Falcons and more than 500 U.S. Air Force personnel in support of Thracian Star 2012, a month-long joint training exercise focused on building partnerships and increasing interoperability with the Bulgarian pilots, maintainers, joint terminal air controllers, firefighters and security forces Airmen.