Narrative:

During ILS approach to runway 35L at den a TCASII 'RA' was activated due to another aircraft on the ILS to runway 35R. We had been cleared for the ILS runway 35L from 10000 ft outside of chola intersection. As we left 10000 ft on the GS and localizer to runway 35L a TCASII 'RA' was activated, which we followed. We notified ATC of the 'RA.' after notifying ATC of the 'RA' we were told of parallel traffic directly abeam us on the ILS to runway 35R level at 9000 ft that had not yet intercepted the GS. After termination of the 'RA' and acquiring the other aircraft both visually and on TCASII, we continued the approach since we were still 17 NM out with flaps 10 degrees, only now in the 'TA' TCASII mode. The rest of the approach and landing was uneventful. It was interesting to note that the only time parallel approachs were mentioned was on the ATIS. Our parallel traffic was only mentioned to us after our 'RA'. Also it is a generally known fact that the standard separation for parallel simultaneous approachs at den does not exist because of the altitude of the airport. The airport is doing the approachs with a waiver from the FAA. Callback conversation with reporter revealed the following information: the reporter was flying a B737-300 and the other aircraft was a beech 1900. The in-flight visibility was about 2 mi according to the captain and he said that he could see the other aircraft. The captain said that he was surprised when the 'RA' sounded. After he established the other aircraft's relationship to his intended path he continued his approach and placed the TCASII mode selector in 'TA only.'

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Original NASA ASRS Text

Title: EVASIVE ACTION CLB -- ACR ON APCH GETS AN 'RA' AND STARTS TO CLB WHILE ADVISING THE CTLR. THE CTLR TELLS THE ACR THAT ANOTHER IS LOWER AND ON A PARALLEL APCH. AFTER ACQUISITION THE APCH IS CONTINUED WITH THE TCASII IN 'TA ONLY' MODE.

Narrative: DURING ILS APCH TO RWY 35L AT DEN A TCASII 'RA' WAS ACTIVATED DUE TO ANOTHER ACFT ON THE ILS TO RWY 35R. WE HAD BEEN CLRED FOR THE ILS RWY 35L FROM 10000 FT OUTSIDE OF CHOLA INTXN. AS WE LEFT 10000 FT ON THE GS AND LOC TO RWY 35L A TCASII 'RA' WAS ACTIVATED, WHICH WE FOLLOWED. WE NOTIFIED ATC OF THE 'RA.' AFTER NOTIFYING ATC OF THE 'RA' WE WERE TOLD OF PARALLEL TFC DIRECTLY ABEAM US ON THE ILS TO RWY 35R LEVEL AT 9000 FT THAT HAD NOT YET INTERCEPTED THE GS. AFTER TERMINATION OF THE 'RA' AND ACQUIRING THE OTHER ACFT BOTH VISUALLY AND ON TCASII, WE CONTINUED THE APCH SINCE WE WERE STILL 17 NM OUT WITH FLAPS 10 DEGS, ONLY NOW IN THE 'TA' TCASII MODE. THE REST OF THE APCH AND LNDG WAS UNEVENTFUL. IT WAS INTERESTING TO NOTE THAT THE ONLY TIME PARALLEL APCHS WERE MENTIONED WAS ON THE ATIS. OUR PARALLEL TFC WAS ONLY MENTIONED TO US AFTER OUR 'RA'. ALSO IT IS A GENERALLY KNOWN FACT THAT THE STANDARD SEPARATION FOR PARALLEL SIMULTANEOUS APCHS AT DEN DOES NOT EXIST BECAUSE OF THE ALT OF THE ARPT. THE ARPT IS DOING THE APCHS WITH A WAIVER FROM THE FAA. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR WAS FLYING A B737-300 AND THE OTHER ACFT WAS A BEECH 1900. THE INFLT VISIBILITY WAS ABOUT 2 MI ACCORDING TO THE CAPT AND HE SAID THAT HE COULD SEE THE OTHER ACFT. THE CAPT SAID THAT HE WAS SURPRISED WHEN THE 'RA' SOUNDED. AFTER HE ESTABLISHED THE OTHER ACFT'S RELATIONSHIP TO HIS INTENDED PATH HE CONTINUED HIS APCH AND PLACED THE TCASII MODE SELECTOR IN 'TA ONLY.'

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.