KABUL, Afghanistan (NEXSTAR) — The operators of military aircraft at Kabul’s airport have been taking evasive maneuvers to prevent possible surface-to-air attacks. But what exactly are they doing, and how are these maneuvers designed to evade missiles?

The Associated Press reports that pilots flying into Kabul are performing corkscrew landings, a tactic that has been used at least as far back as the Vietnam War. It was also heavily executed by commercial airlines in Baghdad following a near-disaster in 2003, when a cargo plane operated by DHL managed to land safely after being hit by a missile.

The maneuver is actually “straightforward,” as described by Smithsonian’s Air & Space magazine. Instead of lining up miles from the runway, pilots fly their aircraft high above the airport, out of range of any ground fire or surface-to-air missiles, and proceed to fly in circles, spiraling down toward the runway below. Once closer to the ground, the plane straightens out before touching down.

“Some of our captains call it boring, because you are flying in circles,” former AirQuarius Aviation pilot Paul Botha told Air & Space in 2006. But Botha, whose airline specialized in flights to areas of political crisis, was really only speaking for the pilots, according to some passenger accounts.

In 2008, the Associated Press said passengers on civilian flights into Baghdad could definitely “feel the pull of gravity” as their planes banked to execute the spiral. In another account shared with Air & Space, one woman on a flight landing in Baghdad clenched her teeth “so hard that she snapped one tooth off.”

In addition to corkscrew landings, pilots taking off from Kabul have also been firing off flares, a tactic designed to protect the plane “by forcing infrared threats, such as heat seeking surface-to-air or air-to-air missiles, to lock onto their heat signatures rather than the aircraft’s engine,” according to an article published by the U.S. Air Force’s Air Mobility Command.

A video released by CBS News illustrates this particular countermeasure, seen in use by a French military plane departing Kabul last week.

Amid the evacuations at Kabul’s airport, corkscrew maneuvers and flares may be a necessity, no matter how “boring” the former is for pilots. The U.S. military has been executing these countermeasures since at least Aug. 22, according to the Associated Press.

The need to safely evacuate Americans and Afghan refugees has taken on a new urgency after a Thursday attack outside Kabul’s airport. The attack, which involved suicide bombings and gunmen, was said to have been carried out by ISIS-K, an offshoot of ISIS. At least 60 people were killed, including 13 U.S. servicemembers.