Incident Overview
On 13 June 2014, an incident occurred in the Warsaw Flight Information Region (FIR EPWW) involving three commercial aircraft: an Embraer 190 (E190), a Boeing 737-800 (B738), and an Airbus A321 (A321). The E190 was operating a flight from Warsaw Chopin Airport (EPWA) to Paris Charles de Gaulle Airport (LFPG). After departure, it began climbing initially to flight level (FL) 320, heading toward the navigational waypoint TOMTI.
Sequence of Events
At the same time, an air traffic controller in the ACC "T" sector was managing the E190 and two other aircraft. The B738 was flying at FL340 toward TOMTI, while the A321 was at FL350 heading toward waypoint DESEN. The controller anticipated a potential conflict between the climbing E190, which had a planned cruise level of FL360, and the B738 and A321.
The controller asked the E190 crew about their vertical speed, to which they responded 1,000 feet per minute (ft/min). The controller then instructed the E190 to maintain an average climb rate of 1,000 ft/min until reaching FL360. The crew acknowledged this instruction, and ATC cleared the E190 to continue climbing to FL360.
As the horizontal distance between the E190 and B738 decreased, the controller ordered the B738 crew to turn right by 5 degrees. Subsequently, the controller asked the E190 crew if they could sustain a climb rate of 1,000 ft/min to FL360. The pilot replied that they could not maintain that vertical speed. In response, the controller instructed the E190 to turn right by 30 degrees and expedite the climb to cross FL350, while also informing them of the conflicting traffic (the B738). Simultaneously, the controller ordered the A321 crew to turn right by 15 degrees.
Separation and Cause
The minimum separation achieved between the E190 and B738 was 6.7 nautical miles (NM) horizontally and 700 feet vertically, falling below the required minimum of 7 NM or 1,000 feet in that airspace.
The cause of the incident was determined to be errors in air traffic control services.
Post-Incident Actions
Following the investigation, the final report was provided to the Local Safety Manager to inform the involved controller and ACC Warsaw personnel about the findings. The collected material was also forwarded to an aviation training center for use in initial and recurrent training for air traffic controllers. No safety recommendations were issued.