Narrative:

We were cruising at 12000 ft, 300 KIAS. Center called VFR at 12 O'clock, 8 mi at 11500 ft. Picked her up on TCASII. The arrow showed she was climbing. We responded we had her on TCASII at 11700 ft and we would probably have to climb due to anticipating a TCASII RA. A few seconds later the RA went off commanding a climb. We followed it and missed the light plane. It indicated 11800 ft as we climbed over it. The light plane was a student pilot, in contact with center, and center reported to us after we were clear that she was having trouble controling her altitude. The center then gave us a phone number to call. The TCASII worked properly and we followed it exactly. 2 big problems, however. 1) why were we allowed by ATC to pass directly over a plane they were in contact with when that plane had a known problem controling its altitude? 2) when I called this special phone number, I feel I was 'grilled' as to why I left my assigned altitude when ATC had both aircraft 'under control.' how come you follow an RA under those circumstances? I felt I was talking to a lawyer, not ATC controller with a genuine interest in understanding why we must follow an RA, and he was fishing to find an altitude deviation violation. Human nature being what it is, the TCASII will be run in TA mode by more and more pilots if the FAA hassles and tries to violate them every time TCASII RA's are followed. Quite frankly, the TCASII might as well be removed and save the money if pilots are penalized for using it. This FAA practice must be stopped pronto! Or a valuable piece of equipment will be lost.

Google
 

Original NASA ASRS Text

Title: LGT FOLLOWS TCASII AND CLBS TO AVOID SMA. IS GRILLED BY ATC BECAUSE HE AVOIDED A 'CTLED' ACFT.

Narrative: WE WERE CRUISING AT 12000 FT, 300 KIAS. CTR CALLED VFR AT 12 O'CLOCK, 8 MI AT 11500 FT. PICKED HER UP ON TCASII. THE ARROW SHOWED SHE WAS CLBING. WE RESPONDED WE HAD HER ON TCASII AT 11700 FT AND WE WOULD PROBABLY HAVE TO CLB DUE TO ANTICIPATING A TCASII RA. A FEW SECONDS LATER THE RA WENT OFF COMMANDING A CLB. WE FOLLOWED IT AND MISSED THE LIGHT PLANE. IT INDICATED 11800 FT AS WE CLBED OVER IT. THE LIGHT PLANE WAS A STUDENT PLT, IN CONTACT WITH CTR, AND CTR RPTED TO US AFTER WE WERE CLR THAT SHE WAS HAVING TROUBLE CTLING HER ALT. THE CTR THEN GAVE US A PHONE NUMBER TO CALL. THE TCASII WORKED PROPERLY AND WE FOLLOWED IT EXACTLY. 2 BIG PROBS, HOWEVER. 1) WHY WERE WE ALLOWED BY ATC TO PASS DIRECTLY OVER A PLANE THEY WERE IN CONTACT WITH WHEN THAT PLANE HAD A KNOWN PROB CTLING ITS ALT? 2) WHEN I CALLED THIS SPECIAL PHONE NUMBER, I FEEL I WAS 'GRILLED' AS TO WHY I LEFT MY ASSIGNED ALT WHEN ATC HAD BOTH ACFT 'UNDER CTL.' HOW COME YOU FOLLOW AN RA UNDER THOSE CIRCUMSTANCES? I FELT I WAS TALKING TO A LAWYER, NOT ATC CTLR WITH A GENUINE INTEREST IN UNDERSTANDING WHY WE MUST FOLLOW AN RA, AND HE WAS FISHING TO FIND AN ALTDEV VIOLATION. HUMAN NATURE BEING WHAT IT IS, THE TCASII WILL BE RUN IN TA MODE BY MORE AND MORE PLTS IF THE FAA HASSLES AND TRIES TO VIOLATE THEM EVERY TIME TCASII RA'S ARE FOLLOWED. QUITE FRANKLY, THE TCASII MIGHT AS WELL BE REMOVED AND SAVE THE MONEY IF PLTS ARE PENALIZED FOR USING IT. THIS FAA PRACTICE MUST BE STOPPED PRONTO! OR A VALUABLE PIECE OF EQUIP WILL BE LOST.

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.