Washington (CNN) -- Five close calls involving passenger jets at big U.S. airports prompted a recommendation on Monday for new rules to prevent planes from getting dangerously close to each other when one aborts a landing.
The National Transportation Safety Board recommended the Federal Aviation Administration (FAA) change its standards to ensure safe aircraft separation in cases of a "go-around." That's when pilots cut short a landing at the last minute and pull up to circle the airport before making another try.
NTSB Chairwoman Deborah Hersman outlined four incidents in 2012 and one in 2006 when planes initiating "go-arounds" and got dangerously close to aircraft taking off or landing.
Three occurred at Las Vegas's McCarran airport, one at New York's John F Kennedy airport and one at Charlotte-Douglass International.
"The NTSB is concerned that in these events, ATC (air traffic control) was not able to ensure the safe separation of aircraft." Hersman wrote in a letter to FAA Administrator Michael Huerta.
Crashes were only avoided because pilots took evasive maneuvers, she wrote.
The FAA oversees air traffic operations.
In each of the incidents, the flight paths would not have intersected had the plane landed successfully instead of conducting the "go around."
Controllers under current rules are required to ensure there is enough space between aircraft during take offs and landings. But there is a gap in regulations when those paths converge during "go arounds," the NTSB said.
The FAA said in a statement that it takes the recommendations seriously and will respond within 90 days.
The FAA said its thoroughly investigated the close-call incidents and took aggressive steps to address the causes.
The incidents cited by the NTSB include:
On July 30, 2012, a Spirit Airlines Airbus A319 was executing a go around at Las Vegas and came within a quarter mile horizontally, and 100 feet vertically of a Cessna Citation landing on a separate runway.
The same day at JFK, an American Airlines Boeing 737 aborted landing and came within a third of a mile horizontally and 300 feet vertically a from a Pinnacle Airlines CRJ-200 regional jet. The NTSB reported the pilot of the American jet radioed "we are turning as tightly as we can" while the Pinnacle pilot said on another frequency "we are trying not to hit this aircraft off our right."
On July 14, 2012, an ExpressJet Embraer 145 at Charlotte came within 1,000 feet horizontally and 400 feet vertically of an Air Wisconsin CRJ that was departing.
On April 26, 2012, a Jet Blue A320 conducting a go around came within a third of a mile horizontally and 100 feet vertically of a Learjet 60 at Las Vegas.
On January 27, 2006, a United Airlines A320 aborted a landing and came within 1,400 feet horizontally and 300 feet vertically of a departing American 757 at Las Vegas.