Narrative:

While being vectored to and on a left downwind for runway 17L at okc, arriving from the sse, we received aircraft, above, below, and level with us. Airspace was saturated at this time. When approximately abeam the runway 17L touchdown zone, we also observed a twin cessna tracking towards wiley post field, cutting across both finals at will rogers world airport, in addition to many other aircraft in the area. About this time, I, PNF, spotted what appeared to be an OH58/jetranger at our 12 O'clock position and level, less than 1 mi ahead. I immediately referenced the TCASII display as the aircraft went to amber/with a -300 ft altitude readout, and we then received an RA to climb. The first officer, PF, immediately reacted as trained and climbed up from our 4000 ft assigned to approximately 4300 ft. The TCASII then issued a monitor vertical speed command followed immediately by a clear of conflict advisory. I reported to ATC during the RA that we had an RA and he emphatically commanded us that we did not need to follow it as the aircraft was 500 ft below us. I replied that we were complying with the RA. It appeared that just as we were starting to follow the RA that the helicopter turned directly towards us and entered autorotation, or a very rapid descent dropping under the nose of our aircraft. In defense of ATC, the airspace was really a mess at this time, as there were many VFR and mixed type aircraft in the area at this time. The only TA we received.

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Original NASA ASRS Text

Title: AN ACR FK10 FLC RESPONDS PROPERLY TO AN RA BY CLBING ABOVE THEIR ASSIGNED ALT TO AVOID A BH12.

Narrative: WHILE BEING VECTORED TO AND ON A L DOWNWIND FOR RWY 17L AT OKC, ARRIVING FROM THE SSE, WE RECEIVED ACFT, ABOVE, BELOW, AND LEVEL WITH US. AIRSPACE WAS SATURATED AT THIS TIME. WHEN APPROX ABEAM THE RWY 17L TOUCHDOWN ZONE, WE ALSO OBSERVED A TWIN CESSNA TRACKING TOWARDS WILEY POST FIELD, CUTTING ACROSS BOTH FINALS AT WILL ROGERS WORLD ARPT, IN ADDITION TO MANY OTHER ACFT IN THE AREA. ABOUT THIS TIME, I, PNF, SPOTTED WHAT APPEARED TO BE AN OH58/JETRANGER AT OUR 12 O'CLOCK POS AND LEVEL, LESS THAN 1 MI AHEAD. I IMMEDIATELY REFED THE TCASII DISPLAY AS THE ACFT WENT TO AMBER/WITH A -300 FT ALT READOUT, AND WE THEN RECEIVED AN RA TO CLB. THE FO, PF, IMMEDIATELY REACTED AS TRAINED AND CLBED UP FROM OUR 4000 FT ASSIGNED TO APPROX 4300 FT. THE TCASII THEN ISSUED A MONITOR VERT SPD COMMAND FOLLOWED IMMEDIATELY BY A CLR OF CONFLICT ADVISORY. I RPTED TO ATC DURING THE RA THAT WE HAD AN RA AND HE EMPHATICALLY COMMANDED US THAT WE DID NOT NEED TO FOLLOW IT AS THE ACFT WAS 500 FT BELOW US. I REPLIED THAT WE WERE COMPLYING WITH THE RA. IT APPEARED THAT JUST AS WE WERE STARTING TO FOLLOW THE RA THAT THE HELI TURNED DIRECTLY TOWARDS US AND ENTERED AUTOROTATION, OR A VERY RAPID DSCNT DROPPING UNDER THE NOSE OF OUR ACFT. IN DEFENSE OF ATC, THE AIRSPACE WAS REALLY A MESS AT THIS TIME, AS THERE WERE MANY VFR AND MIXED TYPE ACFT IN THE AREA AT THIS TIME. THE ONLY TA WE RECEIVED.

Data retrieved from NASA's ASRS site as of July 2007 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.