The present version of the Quick Reaction Alert (Intercept) or QRA(I) fighter aircraft – the MiG-21BisD/UMD – is the most visible Croatian Air Force resource for NATO Air Policing. The jets are assigned to 191st Fighter Aircraft Squadron of 91st Wing of the Croatian Air Force and located in the "Pukovnik Marko Živković" Barracks near Zagreb. 

The Republic of Croatia is committed to retaining the capability to contribute to safeguarding NATO airspace

"Over the past years the on-duty QRA(I) fighters have regularly intercepted aircraft, most of the time caused by unintentional communication losses with Croatia Control, our civilian air traffic control agency", said Brigadier General Michael Križanec, the Commander of the Croatian Air Force. "We regularly conduct training drills to maintain our mission readiness in close coordination with NATO's Combined Air Operations Centre (CAOC) at Torrejón, Spain", he added. 

Croatia's air surveillance and control system is operated by the Airspace Surveillance and Control Battalion, which is closely integrated into NATINAMDS. The battalion's Control and Reporting Centre (CRC) at Podvornica (near Zagreb) protects the integrity of the Croatian airspace and contributes to safeguarding NATO Allies' airspace. With radar sites throughout the country, the centre operates U.S.-made 3D FPS 117 air search radars to generate a complete recognised air picture showing all   airspace   users.  This   picture    allows 

constant situational awareness and is shared with end users in the Republic of Croatia and abroad, including NATO's CRCs in nearby Italy, the CAOC in Spain and Allied Air Command in Ramstein, Germany.

The CRC and the on-duty QRA(I) aircraft provide surveillance and protection of the Croatian airspace. When an aircraft without clearance, deviating from the planned route or without proper radio communication with the air traffic control enters the airspace, QRA(I) fighters are scrambled to intercept and visually identify an aircraft in accordance with NATO and national procedures, depending on the situation. In most cases the QRA(I) fighter pilots ensure the aircraft's radio contacts are re-established or provide navigation assistance in emergency situations. 

"The Airspace Surveillance and Control Battalion staff conduct 24/7 operations and take part in training activities and exercises organised by Allied Air Command and by the CAOC, to ensure the same level of airspace protection across the Alliance," said Brigadier General Križanec. "The Croatian Air Force officers and NCOs also perform duties within NATO units engaged in the system of control and surveillance of the airspace; the Republic of Croatia is committed to retaining the capability to contribute to safeguarding NATO airspace. In spring 2020 Croatia started procurement procedures for a new multi-purpose 4th generation fighter aircraft to ensure and expand this capability in the future," he added. 

The Republic of Croatia became a full NATO member in 2009 and declared forces for NATINAMDS. Unlike other smaller new Alliance members, Croatia has an autonomous Air Policing capability provided by their mission-proven MiG-21 fighter aircraft.