What happened
PenAir Flight 4266, an aircraft cleared for a localizer DME approach to runway 19, encountered another airplane during its descent. The crew of the flight broke out of the cloud layer at 800 feet MSL, located 4.8 DME from the airport. Upon exiting the clouds, the crew immediately observed another aircraft positioned directly in front of them.
Following immediate evasive maneuvers by the crew, the two aircraft passed within 100 feet of each other.
A special weather observation had been recorded one minute prior to the near mid-air collision; however, this specific observation had not yet been transmitted to air traffic services. This untransmitted data indicated that the control zone was actually below visual meteorological conditions (VMC). At the time of the event, the most recent transmitted hourly observation and the previous hourly observation both indicated that the control zone was operating under visual meteorological conditions.