Medium Transport; Low Wing; 2 Turbojet Eng
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 10
Situational Awareness
Conflict NMAC; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Weather / Turbulence
Flight Crew Became Reoriented
Human Factors; Procedure; Weather; Airspace Structure
Aircraft X was on a Visual Approach to the right runway. Aircraft Y was on the Visual Approach to the left runway. About a mile out Aircraft Y made a hard right turn; in what appeared to be an attempt to land on the right runway. From the tower they appeared almost directly above Aircraft X. They were descending to land on top of Aircraft X. At the last second they realized their mistake and made a left turn to head back to the left runway. They missed by maybe an airplane length. The weather was deteriorating rapidly; with wind-shear alerts; and heavy rain moving in. We as controllers make a request several times to stop the left parallel runway arrivals due to the weather moving in. After the near miss; they stopped the left runway arrivals.Both airplanes are on separate frequencies heading towards each other to land side by side. It does not seem like the safest operation.
Making a Visual Approach overshot runway centerline. We got closer to runway centerline of parallel right runway than I would have liked. Aircraft landing on the right runway was in sight and no collision or evasive maneuvers were required or used. No RA was issued. Aircraft on the right runway was lower than we were. Tower never said anything and we landed uneventfully.Rain shower had just moved over approach area.
An aircraft on a Visual Approach overshot the final approach course and conflicted with an aircraft on approach to the parallel runway at PHL. The Tower Controller reported a NMAC. The flight crew of the deviating aircraft had the parallel traffic in sight.