Narrative:

ATC instructed us to descend to 5;000; inbound. Shortly thereafter; a cessna 172 that had departed contacted ATC for VFR flight following to his destination; with a cruise altitude of 7;500'. Cessna pilot reported altitude as 3;500'. Cessna's on course heading and our heading to the airport were directly in line with each other. ATC advised cessna pilot of us being at 12 o'clock and 6 miles at 5;000; and then advised us of cessna traffic at 12 o'clock and 6 miles out of 4;000. We tracked the TCAS target on the EFIS; while simultaneously visually scanning the area for the cessna aircraft. Our TCAS issued a traffic alert and the target turned to a yellow diamond. At that time; the target was 600' below and still climbing. At a mile and a half separation; still without the cessna in sight; TCAS issued an RA climb instruction; with a vertical speed command of approximately 1500 FPM. As I started the climb maneuver; both the first officer and I spotted the aircraft simultaneously. I followed through with the RA commands; climbing approximately 300' before clear of the conflict. As we were in the RA climb; cessna pilot reported to ATC that he had us in sight and that '[we were] beautiful up there'. Once clear of conflict; I returned the aircraft to 5000' and the remainder of the flight was uneventful. It appeared that the cessna pilot continued to climb even though it should have been apparent that leveling at 4;500 would have been a prudent decision. Neither terrain; obstacles; or clouds would not have been a factor for him to level at 4;500 until he was clear of any potential conflict.

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Original NASA ASRS Text

Title: HS125 Captain at 5000 FT; reports conflict with C172 departing the same airport. Each is advised of the other by TRACON but C172 pilot continued climb toward 7500 FT until a TCAS RA was generated aboard the HS125 where evasive action is taken.

Narrative: ATC instructed us to descend to 5;000; inbound. Shortly thereafter; a Cessna 172 that had departed contacted ATC for VFR flight following to his destination; with a cruise altitude of 7;500'. Cessna pilot reported altitude as 3;500'. Cessna's on course heading and our heading to the airport were directly in line with each other. ATC advised Cessna pilot of us being at 12 o'clock and 6 miles at 5;000; and then advised us of Cessna traffic at 12 o'clock and 6 miles out of 4;000. We tracked the TCAS target on the EFIS; while simultaneously visually scanning the area for the Cessna aircraft. Our TCAS issued a traffic alert and the target turned to a yellow diamond. At that time; the target was 600' below and still climbing. At a mile and a half separation; still without the Cessna in sight; TCAS issued an RA climb instruction; with a vertical speed command of approximately 1500 FPM. As I started the climb maneuver; both the First Officer and I spotted the aircraft simultaneously. I followed through with the RA commands; climbing approximately 300' before clear of the conflict. As we were in the RA climb; Cessna pilot reported to ATC that he had us in sight and that '[we were] beautiful up there'. Once clear of conflict; I returned the aircraft to 5000' and the remainder of the flight was uneventful. It appeared that the Cessna pilot continued to climb even though it should have been apparent that leveling at 4;500 would have been a prudent decision. Neither terrain; obstacles; or clouds would not have been a factor for him to level at 4;500 until he was clear of any potential conflict.

Data retrieved from NASA's ASRS site as of April 2012 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.