Narrative:

While cruising level at FL280 the TCASII system began to scream 'climb, climb, climb' without any normally present preliminary TA's or any change of a target blip to yellow. I glanced at the TCASII scope and saw a red target block at about 11:00-11:30 O'clock which appeared to nearly touch the airplane icon on the scope (40 mi scale). I disconnected the autoplt and commenced a climb while going outside visually to fly an avoidance maneuver. We had seen the subject target previously and it had appeared to be lower and not a potential conflict, however, it was now in so close (I would estimate less than a mi) and the horizon reference was poor due to a ragged undercast so that I could not be sure that no conflict had developed. I flew a primarily visual avoidance path above, to the right of, and then rapidly down behind the target to get back to our assigned altitude. Unfortunately in the extremely intense, very high stress, very noise 10-15 seconds of the incident, I suffered a momentary confusion and corrected aggressively toward FL260 not the correct FL280, deviating my altitude the other direction. Fortunately, this did not create a conflict with any other oncoming traffic at FL270 and I had the 'intruder' target at FL270 visually clear. Most unfortunately of all is the fact that the incident should never have occurred. Center verified as does a preliminary radar tape that there never was a conflict, both aircraft were level at FL270 and FL280 respectively. This was a totally inappropriate TCASII RA. In addition to the obvious failure of the ever more painfully obviously inadequate TCASII system, I think there is at least a couple of other negative factors which caused serious deterioration of this incident beyond the needless ATC deviation caused by the erroneous, yet mandatory climb command issued by TCASII. On the large transport, intentional as well as unintentional disconnect of the autoplt generates an extremely loud aural warning, loud enough to end all communication within as well as to or from the cockpit, and to seriously interfere with mental processes. Most of us seldom hear it because we have learned to 'double click' to disconnect the autoplt and silence the aural. In the extreme haste and intensity of this high stress event I evidently did not get the second click done and the autoplt warning warning warbled the entire duration of the incident. I was too intent on the avoidance maneuver to analyze why the cockpit was so noisy. The TCASII warning is also extremely loud and between the two, not only could the first officer and I not talk to each other or center, we could not hear the aural warning upon leaving our altitude or going back down through it. Had I been able to hear it I probably would have recognized my error on the recovery and not committed the second deviation. Many of these aural warnings are now so overdone and so loud they often become a part of the problem as the cockpit degenerates into an undecipherable cacophony of noise in many sits. I particularly don't understand why an intentional disconnect of the autoplt should require such a loud emergency type warning. Many intentional autoplt disconnects occur in response to emergency aural warnings such as TCASII RA's or GPWS alerts and if the autoplt warning is inadvertently left unsilenced, the tendency during such a high stress situation is to subconsciously associate the resulting noise with the true emergency being handled and to just live with it. You see this syndrome in the simulator all the time. I think the excessive noise was definitely a contributing factor in this incident. I don't think the TCASII system needs much discussion here. Suffice to say that while my confidence level in the system was shaky before it is now less than '0', in fact TCASII now scares me to death! In my opinion it is just a matter of time until this system causes a horrendous accident. Supplemental information from acn 258203: the RA was activated by a northbound aircraft that I had been watching approach from our 11:30 position. I first saw the aircraft at a distance of 5-8 mi. It appeared to be below our altitude and idid not consider it a factor. Although I was not monitoring the TCASII screen continuously, I do not recall it having displayed a TA yellow symbol.

Related reports:

Google
 

Original NASA ASRS Text

Title: ALTDEV ACCOUNT TCASII RA.

Narrative: WHILE CRUISING LEVEL AT FL280 THE TCASII SYS BEGAN TO SCREAM 'CLB, CLB, CLB' WITHOUT ANY NORMALLY PRESENT PRELIMINARY TA'S OR ANY CHANGE OF A TARGET BLIP TO YELLOW. I GLANCED AT THE TCASII SCOPE AND SAW A RED TARGET BLOCK AT ABOUT 11:00-11:30 O'CLOCK WHICH APPEARED TO NEARLY TOUCH THE AIRPLANE ICON ON THE SCOPE (40 MI SCALE). I DISCONNECTED THE AUTOPLT AND COMMENCED A CLB WHILE GOING OUTSIDE VISUALLY TO FLY AN AVOIDANCE MANEUVER. WE HAD SEEN THE SUBJECT TARGET PREVIOUSLY AND IT HAD APPEARED TO BE LOWER AND NOT A POTENTIAL CONFLICT, HOWEVER, IT WAS NOW IN SO CLOSE (I WOULD ESTIMATE LESS THAN A MI) AND THE HORIZON REF WAS POOR DUE TO A RAGGED UNDERCAST SO THAT I COULD NOT BE SURE THAT NO CONFLICT HAD DEVELOPED. I FLEW A PRIMARILY VISUAL AVOIDANCE PATH ABOVE, TO THE R OF, AND THEN RAPIDLY DOWN BEHIND THE TARGET TO GET BACK TO OUR ASSIGNED ALT. UNFORTUNATELY IN THE EXTREMELY INTENSE, VERY HIGH STRESS, VERY NOISE 10-15 SECONDS OF THE INCIDENT, I SUFFERED A MOMENTARY CONFUSION AND CORRECTED AGGRESSIVELY TOWARD FL260 NOT THE CORRECT FL280, DEVIATING MY ALT THE OTHER DIRECTION. FORTUNATELY, THIS DID NOT CREATE A CONFLICT WITH ANY OTHER ONCOMING TFC AT FL270 AND I HAD THE 'INTRUDER' TARGET AT FL270 VISUALLY CLR. MOST UNFORTUNATELY OF ALL IS THE FACT THAT THE INCIDENT SHOULD NEVER HAVE OCCURRED. CTR VERIFIED AS DOES A PRELIMINARY RADAR TAPE THAT THERE NEVER WAS A CONFLICT, BOTH ACFT WERE LEVEL AT FL270 AND FL280 RESPECTIVELY. THIS WAS A TOTALLY INAPPROPRIATE TCASII RA. IN ADDITION TO THE OBVIOUS FAILURE OF THE EVER MORE PAINFULLY OBVIOUSLY INADEQUATE TCASII SYS, I THINK THERE IS AT LEAST A COUPLE OF OTHER NEGATIVE FACTORS WHICH CAUSED SERIOUS DETERIORATION OF THIS INCIDENT BEYOND THE NEEDLESS ATC DEV CAUSED BY THE ERRONEOUS, YET MANDATORY CLB COMMAND ISSUED BY TCASII. ON THE LGT, INTENTIONAL AS WELL AS UNINTENTIONAL DISCONNECT OF THE AUTOPLT GENERATES AN EXTREMELY LOUD AURAL WARNING, LOUD ENOUGH TO END ALL COM WITHIN AS WELL AS TO OR FROM THE COCKPIT, AND TO SERIOUSLY INTERFERE WITH MENTAL PROCESSES. MOST OF US SELDOM HEAR IT BECAUSE WE HAVE LEARNED TO 'DOUBLE CLICK' TO DISCONNECT THE AUTOPLT AND SILENCE THE AURAL. IN THE EXTREME HASTE AND INTENSITY OF THIS HIGH STRESS EVENT I EVIDENTLY DID NOT GET THE SECOND CLICK DONE AND THE AUTOPLT WARNING WARNING WARBLED THE ENTIRE DURATION OF THE INCIDENT. I WAS TOO INTENT ON THE AVOIDANCE MANEUVER TO ANALYZE WHY THE COCKPIT WAS SO NOISY. THE TCASII WARNING IS ALSO EXTREMELY LOUD AND BTWN THE TWO, NOT ONLY COULD THE FO AND I NOT TALK TO EACH OTHER OR CTR, WE COULD NOT HEAR THE AURAL WARNING UPON LEAVING OUR ALT OR GOING BACK DOWN THROUGH IT. HAD I BEEN ABLE TO HEAR IT I PROBABLY WOULD HAVE RECOGNIZED MY ERROR ON THE RECOVERY AND NOT COMMITTED THE SECOND DEV. MANY OF THESE AURAL WARNINGS ARE NOW SO OVERDONE AND SO LOUD THEY OFTEN BECOME A PART OF THE PROB AS THE COCKPIT DEGENERATES INTO AN UNDECIPHERABLE CACOPHONY OF NOISE IN MANY SITS. I PARTICULARLY DON'T UNDERSTAND WHY AN INTENTIONAL DISCONNECT OF THE AUTOPLT SHOULD REQUIRE SUCH A LOUD EMER TYPE WARNING. MANY INTENTIONAL AUTOPLT DISCONNECTS OCCUR IN RESPONSE TO EMER AURAL WARNINGS SUCH AS TCASII RA'S OR GPWS ALERTS AND IF THE AUTOPLT WARNING IS INADVERTENTLY LEFT UNSILENCED, THE TENDENCY DURING SUCH A HIGH STRESS SIT IS TO SUBCONSCIOUSLY ASSOCIATE THE RESULTING NOISE WITH THE TRUE EMER BEING HANDLED AND TO JUST LIVE WITH IT. YOU SEE THIS SYNDROME IN THE SIMULATOR ALL THE TIME. I THINK THE EXCESSIVE NOISE WAS DEFINITELY A CONTRIBUTING FACTOR IN THIS INCIDENT. I DON'T THINK THE TCASII SYS NEEDS MUCH DISCUSSION HERE. SUFFICE TO SAY THAT WHILE MY CONFIDENCE LEVEL IN THE SYS WAS SHAKY BEFORE IT IS NOW LESS THAN '0', IN FACT TCASII NOW SCARES ME TO DEATH! IN MY OPINION IT IS JUST A MATTER OF TIME UNTIL THIS SYS CAUSES A HORRENDOUS ACCIDENT. SUPPLEMENTAL INFORMATION FROM ACN 258203: THE RA WAS ACTIVATED BY A NBOUND ACFT THAT I HAD BEEN WATCHING APCH FROM OUR 11:30 POS. I FIRST SAW THE ACFT AT A DISTANCE OF 5-8 MI. IT APPEARED TO BE BELOW OUR ALT AND IDID NOT CONSIDER IT A FACTOR. ALTHOUGH I WAS NOT MONITORING THE TCASII SCREEN CONTINUOUSLY, I DO NOT RECALL IT HAVING DISPLAYED A TA YELLOW SYMBOL.

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.