B757 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Conflict Airborne Conflict; Deviation - Altitude Excursion From Assigned Altitude
Air Traffic Control Issued Advisory / Alert; Flight Crew Took Evasive Action
Airspace Structure; Human Factors
During the TYSSN 3 arrival to LAS; we were given KADDY at 12;000 feet and 250 by LA Center. Out of 13 000 feet; LA Center called traffic ahead; VFR at 11;500 feet; a Cirrus. As we went through 12;500 feet; we received a TA quickly followed by an RA to climb. We followed the procedure; climbed to 12;500 feet before we were clear of the conflict. The TCAS display indicated the traffic was at 11;800 feet; not 12;000 [11;500 feet]. Advised LA Center and was switched to Las Vegas Approach. Landed uneventfully.
B757 Captain reports a TCAS RA approaching KADDY on the arrival to LAS. Evasive action is taken.