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Plane collisions are incredibly rare, but still the source of many people's flying fears. One air safety study conducted over decades showed there's an average of one-and-a-half in-air plane crashes a year.
Every plane is closely monitored from the ground by a team of air traffic controllers, so most dangerous situations can be spotted well in advance and averted by one or either of the planes' pilots. Runway crashes are more common but still very rare.
Don't Miss: Planes collide following near miss at same airport earlier this week
Even so, some close calls do occur and make for splashy news stories. On August 11, a private Cessna Citation jet narrowly avoided crashing into a Southwest Airlines (LUV) -) plane when preparing to land at San Diego International Airport.
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Private jet cleared to land in same runway space as Southwest plane
The National Transportation Safety Board (NTSB) is currently investigating the incident. They wrote on Twitter that a "runway incursion and overflight" occurred when "a Cessna 560X was cleared to land on Runway 27 and conflicted with a Southwest Airlines Boeing (BA) -) 737."
NTSB Chair Jennifer Homendy later told CNN that the Cessna came "within 100 feet” of the Southwest passenger plane and narrowly missed a collision. Southwest's Flight 2493 was preparing to leave San Diego's airport for San Jose.
The collision was averted when an air traffic controller spotted the Southwest plane in the spot where the private jet was supposed to land and called off instructions to descend. Still, Homendy said the fact that the two planes came so close is a "big concern for [her] and the agency."
'I worry about potential tragedy,' says NTSB chair
"I worry about potential tragedy," she told CNN. In this case, no injuries occurred.
The Federal Aviation Authority is also reviewing to see where the wires got crossed.
"The controller had previously cleared the Citation to land on Runway 27 and then instructed Southwest Flight 2493 to taxi onto that runway and wait for instructions to depart," the preliminary report says. "The facility's automated surface surveillance system alerted the controller about the developing situation."
Audio captured from the incident also reveals that the pilot of the Cessna had repeatedly double-checked whether it was safe to land.
“Verify Four Hotel Victor is still clear to land?” the pilot is heard asking.
“Citation Four Hotel Victor go around, fly the published missed approach,” responds the air traffic controller in the tower.
At the end of July, an in-air collision was averted when the pilot of an Allegiant Air flight flying into Kentucky's Lexington from Fort Lauderdale "received an automated alert about another aircraft at the same altitude" and immediately "took evasive action" to avoid crashing into a private Gulfstream jet.
The sudden swerve sent two flight attendants flying backward (one was later treated for injuries) and gave a huge shock to the passengers aboard.
"It honestly felt like a roller coaster, like when you come down from the highest point, and then you take a big hill," one of the passengers on the flight told news outlets upon landing.