Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 200; Flight Crew Total 23000; Flight Crew Type 10000
ATC Issue All Types; Conflict Airborne Conflict; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Flight Crew Became Reoriented; Flight Crew Returned To Clearance; Flight Crew Took Evasive Action
Human Factors
Crew had accepted descent to FL350 meant for another aircraft with similar sounding call sign. After some time at FL350; crew noticed aircraft (TCAS) at same altitude; opposite direction. Crew began deviation but subsequently received RA. Then began climb back to FL360.
While in cruise flight at FL360 we were given a descent to FL350 and given a frequency change to 124.875. We began our descent and switched frequencies. It took a several calls to the Controller to check-in. At the same time I noticed a primary target on the TCAS display about 25 miles in front of us at the same altitude and closing. I stated to the Captain that 'something isn't right here' and shortly thereafter we got a TCAS RA to climb and a right turn of 15 degrees. We executed the proper procedure for a TCAS event and cleared the conflict quickly. We returned to FL360 and changed back to our previous frequency. The Controller asked what had happened and we explained that we had received and read back the descent and frequency change. All three pilots in the flight deck at the time Ccheck Airmen was occupying the jumpseat) heard the clearance to descend and change frequencies along with my read back. The flight continued with no further incidents.
Air carrier flight crew reports accepting a descent clearance meant for another flight along with a frequency change. At the new altitude a TCAS RA is generated and the crew returns to FL360 and to the previous frequency.