Amid regulatory efforts to reduce errors by air traffic controllers, a controller mistake has been identified by the National Transportation Safety Board (NTSB) as the cause of a near mid-air collision last June.

The incident involving a commercial jetliner and a small private plane occurred on June 19 over the Gulfport-Biloxi airport when a tower air traffic controller cleared a commercial passenger flight on the same runway he'd declared cleared for a Cessna 172 a mere 16 seconds earlier..

"While both airplanes were about 300 feet above the airfield, the Embraer passed in front of the Cessna," according to NTSB investigators. "The closest proximity between the two planes was estimated to be 0 feet vertically and 300 feet laterally."

The commercial jetliner, an Express Jet Embraer 145 carrying 50 passengers and 3 crewmembers, and was bound for Houston Bush Intercontinental Airport (IAH) where it landed uneventfully.  

No one in either airplane was injured in the incident.

In May 2010, the NTSB held a forum to highlight the importance of developing and reinforcing the highest standards of professionalism in aviation.

The issue area of pilot and air traffic controller professionalism was added to the NTSB's Most Wanted List of Safety Improvements in May 2011.