Air forces from around the world have gathered deep in the Arava desert in the south of Israel for the past week and a half to take part in the largest aerial exercise in the history of the Israeli Air Force.

The “Blue Flag” exercise, which is continuing through November 3, pits the Israeli Air Force, the United States Air Force, Greece’s Hellenic Air Force and the Polish Air Force against a fictional enemy state, the captain in charge of all IAF exercises told The Times of Israel Thursday night.

A number of other countries, including Germany, also sent pilots and officers to observe the exercise, but did not take part.

This joint drill is the second “Blue Flag” exercise; the first took place in 2013 and was the largest multi-lateral exercise the IAF had ever hosted.

The various air forces collaborated closely through every step of the current exercise, the IAF captain said, from planning to execution and finally to debriefing.

Though the exercise began on October 18, planning for it started nearly eight months ago, the Israeli official said, with an IAF representative contacting each participating country and initially asking, “What do you want to train for?”

Those requests came together to form the plan for “Blue Flag,” which sent Israeli and American F-15 squadrons, along with Israeli, Hellenic and Polish F-16 squadrons, flying through nearly all of Israel’s air space, firing simulated weapons against fictional enemy missile launchers, convoys and aircraft, he said.

Though the drill was intensive and demanding, it was designed more to test the mettle of the men and women behind the controls than to test the technical capabilities of the fighter jets themselves.

“We wanted it to be challenging for the airmen, rather than for the machines,” said the IAF captain, who cannot be named for security reasons.

In order to “put the airmen through their paces,” he explained, the people running the exercise tried to surprise them, putting them in situations where “the pilot doesn’t know where their target is coming from.”

“Blue Flag” ends next Thursday.

A Polish F-16 fighter jet takes off during the 'Blue Flag' exercise at Ovda Airfield near Eilat on Oct. 26, 2015. (Israel Air Force)

A Polish F-16 fighter jet takes off during the ‘Blue Flag’ exercise at Ovda Airfield near Eilat on October 26, 2015. (Israeli Air Force)

Representatives from multiple countries, including the United States and Greece, listen to a briefing during the 'Blue Flag' exercise in southern Israel on Oct. 26, 2015. (Israel Air Force)

Representatives from multiple countries, including the United States and Greece, listen to a briefing during the ‘Blue Flag’ exercise in southern Israel on October 26, 2015. (Israeli Air Force)

An Israeli F-16 prepares for take-off during the 'Blue Flag' exercise at Ovda Airfield near Eilat on Oct. 27, 2015. (Israel Air Force)

An Israeli F-16 prepares for take-off during the ‘Blue Flag’ exercise at Ovda Airfield near Eilat on October 27, 2015. (Israeli Air Force)

Israeli and foreign fighter jets fly in formation over the Red Sea during the 'Blue Flag' exercise at Ovda Airfield near Eilat on Oct. 27, 2015. (Israel Air Force)

Israeli and foreign fighter jets fly in formation over the Red Sea during the ‘Blue Flag’ exercise at Ovda Airfield near Eilat on October 27, 2015. (Israeli Air Force)

A Hellenic Air Force pilot smiles for the camera during the two-week long 'Blue Flag' exercise at Ovda Airfield near Eilat on Oct. 27, 2015. (Israel Air Force)

A Hellenic Air Force pilot smiles for the camera during the two-week long ‘Blue Flag’ exercise at Ovda Airfield near Eilat on October 27, 2015. (Israeli Air Force)

German pilots mingle with representatives from the Israel Air Force, US Air Force, Hellenic Air Force and Polish Air Force during the 'Blue Flag' exercise in Ovda Airfield near Eilat in southern Israel on Oct. 27, 2015. (Israel Air Force)

German pilots mingle with representatives from the Israeli Air Force, US Air Force, Hellenic Air Force and Polish Air Force during the ‘Blue Flag’ exercise in Ovda Airfield near Eilat in southern Israel on October 27, 2015. (Israeli Air Force)

Israeli and American pilots converse during the 'Blue Flag' exercise in Ovda Airfield near Eilat in southern Israel on Oct. 27, 2015. (Israel Air Force)

Israeli and American pilots converse during the ‘Blue Flag’ exercise in Ovda Airfield near Eilat in southern Israel on October 27, 2015. (Israeli Air Force)

Israeli and foreign fighter jets fly in formation through cloudy skies over the Negev desert during the 'Blue Flag' exercise at Ovda Airfield near Eilat on Oct. 27, 2015. (Israel Air Force)

Israeli and foreign fighter jets fly in formation through cloudy skies over the Negev desert during the ‘Blue Flag’ exercise at Ovda Airfield near Eilat on October 27, 2015. (Israeli Air Force)

Israeli pilots, whose faces have been blurred for security reasons, walk over to their aircraft during the 'Blue Flag' exercise at Ovda Airfield near Eilat on Oct. 26, 2015. (Israel Air Force)

Israeli pilots, whose faces have been blurred for security reasons, walk over to their aircraft during the ‘Blue Flag’ exercise at Ovda Airfield near Eilat on October 26, 2015. (Israeli Air Force)

A Greek F-16 fighter jet flies over Israel during the 'Blue Flag' exercise at Ovda Airfield near Eilat on Oct. 21, 2015. (Israel Air Force)

A Greek F-16 fighter jet flies over Israel during the ‘Blue Flag’ exercise at Ovda Airfield near Eilat on October 21, 2015. (Israeli Air Force)

A controller monitors the progress of the 'Blue Flag' exercise at Ovda Airfield near Eilat on Oct. 27, 2015. (Israel Air Force)

A controller monitors the progress of the ‘Blue Flag’ exercise at Ovda Airfield near Eilat on October 27, 2015. (Israeli Air Force)

Air traffic controllers monitor the aircraft taking part in the 'Blue Flag'exercise at Ovda Airfield near Eilat in southern Israel on Oct. 27, 2015. (Israel Air Force)

Air traffic controllers monitor the aircraft taking part in the ‘Blue Flag’ exercise at Ovda Airfield near Eilat in southern Israel on October 27, 2015. (Israeli Air Force)

An Israeli Air Force F-15 fighter jet makes a landing onto a slightly flooded runway during the 'Blue Flag' exercise in southern Israel on Oct. 26, 2015. (Israel Air Force)

An Israeli Air Force F-15 fighter jet makes a landing onto a slightly flooded runway during the ‘Blue Flag’ exercise in southern Israel on October 26, 2015. (Israeli Air Force)