Aircraft Information
Two aircraft were involved: an Airbus A320, registration SU-GBF, operating as flight MSR638, and an Embraer E170, registration SU-GDI, operating as flight MSR337. MSR337 was operated by Express.
Communications
ATC communications took place on frequencies 125.3 MHz and 126.6 MHz. MSR638 was in contact with Area Control Centre (ACC) on 125.3 MHz, while MSR337 communicated on 126.6 MHz. During the incident, ATC issued instructions including "DESCEND" and "CLIMB". MSR638 was also instructed to "PROCEED TO CRS AND HOLD" and to maintain 250 knots for sequence.
Sequence of Events
MSR638 was cruising at Flight Level (FL) 240, while MSR337 was at FL230. A TCAS Traffic Alert (TA) was followed by a Resolution Alert (RA). MSR337 received a RA to descend, and MSR638 received a RA to climb. The aircraft reached a minimum vertical separation of approximately 800 feet. MSR337 descended through FL237, FL227, and FL220, while MSR638 climbed through FL245 to FL250. The Short Term Conflict Alert (STCA) was activated. After the conflict, ATC cleared MSR638 from the conflict and instructed a climb.
Personnel Information
The pilots of both flights held valid licenses (ATPL and CPL) and had completed proficiency checks. Specific check dates are recorded in the investigation source.
Safety Report
A safety report was filed regarding the incident.