Narrative:

During cruise at FL280 we received TA followed by RA. Intruder was 12 O'clock, opposite direction, and climbing rapidly. Intruder did level at FL270. Because of his rate of climb, our RA gave us a 2200 FPM rate of climb, which we complied with. Because the aircraft leveled off, separation was far more than adequate. Neither TCASII nor us knew the altitude was going to level. Frequency congestion prevented us from notifying controller prior to RA (after TA). Our altitude deviation was 850 ft. The RA did not stop until 600 ft and it took 250 ft to stop our 2200 FPM climb. The TA and RA definitely get your attention. It is relatively easy to follow, although this high rate of climb was difficult to make yourself attain quickly. Once the climb is established it is also difficult to reverse. It would have been interesting to determine our separation if the intruder had not leveled off. Thank goodness we'll never know.

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Original NASA ASRS Text

Title: FLC OF AN MLG ACR ACFT CLBED ABOVE ASSIGNED ALT IN RESPONSE TO A TCASII RA.

Narrative: DURING CRUISE AT FL280 WE RECEIVED TA FOLLOWED BY RA. INTRUDER WAS 12 O'CLOCK, OPPOSITE DIRECTION, AND CLBING RAPIDLY. INTRUDER DID LEVEL AT FL270. BECAUSE OF HIS RATE OF CLB, OUR RA GAVE US A 2200 FPM RATE OF CLB, WHICH WE COMPLIED WITH. BECAUSE THE ACFT LEVELED OFF, SEPARATION WAS FAR MORE THAN ADEQUATE. NEITHER TCASII NOR US KNEW THE ALT WAS GOING TO LEVEL. FREQ CONGESTION PREVENTED US FROM NOTIFYING CTLR PRIOR TO RA (AFTER TA). OUR ALTDEV WAS 850 FT. THE RA DID NOT STOP UNTIL 600 FT AND IT TOOK 250 FT TO STOP OUR 2200 FPM CLB. THE TA AND RA DEFINITELY GET YOUR ATTN. IT IS RELATIVELY EASY TO FOLLOW, ALTHOUGH THIS HIGH RATE OF CLB WAS DIFFICULT TO MAKE YOURSELF ATTAIN QUICKLY. ONCE THE CLB IS ESTABLISHED IT IS ALSO DIFFICULT TO REVERSE. IT WOULD HAVE BEEN INTERESTING TO DETERMINE OUR SEPARATION IF THE INTRUDER HAD NOT LEVELED OFF. THANK GOODNESS WE'LL NEVER KNOW.

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.