NEW YORK -- The Federal Aviation Administration is investigating a near-miss by two airplanes over New York City.
The FAA said in a statement Friday that a Delta Airlines Boeing 747 arriving at John F. Kennedy International Airport came close to a Shuttle America Embraer E170 departing from LaGuardia Airport around 3:45 p.m. June 13.
The aircraft were "turning away from each other at the point where they lost the required separation," the FAA said. Both aircraft landed safely.
CBS News has learned the aircraft were separated by four tenths of a mile horizontally and just 200 feet vertically at their closest point.
David Kaminski-Morrow, air transport editor for Flight International, explained that while so called "air proximity incidents" such as the one over New York are routinely investigated by the FAA, they range in severity from, "at one extreme, a simple but non-threatening loss of separation or, at the other, a genuine risk of mid-air collision."
Kaminiski-Morrow told CBSNews.com that all aircraft are supposed to be kept a specific horizontal and vertical distance apart from each other, and it's technically an infringement if they breach those boundaries by any margin.
Kaminski-Morrow noted that most near-misses involve private aircraft, which rely more often on "see-and-avoid principles, rather than commercial airliners which operate in controlled airspace and which are mandated to carry sophisticated anti collision systems."