ALTDEV. PROPER TCASII RA. ATC CAUGHT OVERSHOOT.

Narrative

I WAS CLRED FOR DEP OFF RWY 26. ONCE AIRBORNE; GIVEN CLRNC TO CONTACT DEP CTL. WE WERE CLRED TO 10000 FT. PASSING APPROX 5000 FT MSL; CLRED R TURN TO 350 DEGS. PASSING APPROX 7500 FT MSL; BOTH COPLT AND I HEARD CLRNC TO CLB TO 14000 FT. I READ BACK CLRNC TO CLB TO 14000 FT; SET ALT IN ALT WINDOW AND COPLT ACKNOWLEDGED CLRNC. PASSING 10300 FT; APCH CTL ISSUED 'MAINTAIN 10000 FT; TFC ON ARR AT 12000 FT.' WE ACKNOWLEDGED AND RETURNED TO 10000 FT. THE HIGHEST WE SHOWED WAS 10400 FT. JUST AFTER DEP CTL ISSUED THE 10000 FT CALL; THE TCASII ISSUED AN RA; BUT WE HAD ALREADY STARTED BACK DOWN TO 10000 FT AND HAD TFC IN SIGHT. LOOKING BACK AT THE INCIDENT; I AM NOT SURE IF THE ORIGINAL CLRNC TO 14000 FT WAS FOR US OR NOT. THERE WERE SEVERAL SIMILAR CALL SIGNS ON DEP CTL AT SAME TIME. ALSO; MY READBACK OF CLRNC TO 14000 FT MAY HAVE BEEN COVERED UP BY ANOTHER ACFT RESPONDING AT SAME TIME. SUPPLEMENTAL INFO FROM ACN 292946: AS THE PF I OBVIOUSLY COULDN'T DEVOTE ALL OF MY CONCENTRATION ON THE RADIO XMISSIONS. I WAS GEARING UP FOR A 10000 FT LEVELOFF AT THE SAME TIME WE RECEIVED THE SUPPOSED CLRNC.