Narrative:

I was the PNF and we were on the arrival into ZZZ. We were talking to radar ARTCC. We were at our assigned altitude of 11000 ft. There was an airbus above us at 12000 ft and a king air beneath us at 10000 ft. We were in IMC and I heard ATC tell the king air to expect 11000 ft. The king air must have misunderstood the clearance and started to climb to our altitude 11000 ft. I was monitoring the TCAS because I saw what was happening. I said to my first officer get ready because the king air is starting to climb. The TCAS showed the aircraft beneath us starting to climb and turned yellow. A moment later; it turned red and we got an RA 'climb; climb.' the first officer was a bit slow to respond so I said my aircraft and started the climb. I knew that the airbus was at 12000 ft so I climbed to 11300 ft to avoid the conflict. I told the first officer to call ATC and tell them we were responding to an RA and we were at 11300 ft. Unfortunately; his transmission was blocked so I then called ATC again and told them we had an RA and were now clear of the conflict and returning to our assigned altitude of 11000 ft. ATC was telling the king air to go back to 10000 ft immediately. ATC told us to maintain 11000 ft and contact ZZZ approach. There was no further incident. We continued the approach into ZZZ and landed without any further problems. This event could have been avoided if everyone complied with ATC clrncs and if ATC would have seen the deviation sooner. This is a good example of why positional awareness and seeing the big picture are so important. I was prepared to deal with the RA before it occurred because I was aware of what the other planes in my vicinity were doing.

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Original NASA ASRS Text

Title: AN SF340 AT 11000 FT WAS FORCED TO CLB AWAY FROM A RA TFC CLBING OUT OF 10000 FT WITHOUT CLRNC BUT UP TOWARD OTHER TFC ABOVE THEM AT 12000 FT. ATC RESOLVED THE RA.

Narrative: I WAS THE PNF AND WE WERE ON THE ARR INTO ZZZ. WE WERE TALKING TO RADAR ARTCC. WE WERE AT OUR ASSIGNED ALT OF 11000 FT. THERE WAS AN AIRBUS ABOVE US AT 12000 FT AND A KING AIR BENEATH US AT 10000 FT. WE WERE IN IMC AND I HEARD ATC TELL THE KING AIR TO EXPECT 11000 FT. THE KING AIR MUST HAVE MISUNDERSTOOD THE CLRNC AND STARTED TO CLB TO OUR ALT 11000 FT. I WAS MONITORING THE TCAS BECAUSE I SAW WHAT WAS HAPPENING. I SAID TO MY FO GET READY BECAUSE THE KING AIR IS STARTING TO CLB. THE TCAS SHOWED THE ACFT BENEATH US STARTING TO CLB AND TURNED YELLOW. A MOMENT LATER; IT TURNED RED AND WE GOT AN RA 'CLB; CLB.' THE FO WAS A BIT SLOW TO RESPOND SO I SAID MY ACFT AND STARTED THE CLB. I KNEW THAT THE AIRBUS WAS AT 12000 FT SO I CLBED TO 11300 FT TO AVOID THE CONFLICT. I TOLD THE FO TO CALL ATC AND TELL THEM WE WERE RESPONDING TO AN RA AND WE WERE AT 11300 FT. UNFORTUNATELY; HIS XMISSION WAS BLOCKED SO I THEN CALLED ATC AGAIN AND TOLD THEM WE HAD AN RA AND WERE NOW CLR OF THE CONFLICT AND RETURNING TO OUR ASSIGNED ALT OF 11000 FT. ATC WAS TELLING THE KING AIR TO GO BACK TO 10000 FT IMMEDIATELY. ATC TOLD US TO MAINTAIN 11000 FT AND CONTACT ZZZ APCH. THERE WAS NO FURTHER INCIDENT. WE CONTINUED THE APCH INTO ZZZ AND LANDED WITHOUT ANY FURTHER PROBS. THIS EVENT COULD HAVE BEEN AVOIDED IF EVERYONE COMPLIED WITH ATC CLRNCS AND IF ATC WOULD HAVE SEEN THE DEV SOONER. THIS IS A GOOD EXAMPLE OF WHY POSITIONAL AWARENESS AND SEEING THE BIG PICTURE ARE SO IMPORTANT. I WAS PREPARED TO DEAL WITH THE RA BEFORE IT OCCURRED BECAUSE I WAS AWARE OF WHAT THE OTHER PLANES IN MY VICINITY WERE DOING.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.