Narrative:

At long beach airport, the left downwind for runway 25L passes over the runway 30 final approach course about 1 mi out. The airplanes landing on runway 30 generally pass about 500 ft below the runway 25L downwind traffic. I am required to give TA's to all aircraft concerned when approachs are being made to both runways. Timing at the runway 25L-30 intersection is critical. The intersection must be clear of any crossing traffic before an aircraft can cross either threshold. On this occasion, there were 2 small aircraft's turning downwind for runway 25L (left traffic) and a TCASII equipped medium large transport at 'becca' (LOM for ILS 30 lgb), along with several other aircraft on frequency. He first medium large transport had been cleared to land runway 25L, with the medium large transport following through the intersection on runway 30, also with clearance to land. The second small aircraft X was instructed to extend downwind for an medium large transport landing 30. Traffic was given to both the small aircraft X extending and the medium large transport on final due to the poor visibility, (3 mi) the medium large transport could not see the small aircraft X therefore, it was my responsibility to provide the required visual separation. The medium large transport passed below and behind the small aircraft X and landed, after I had advised both aircraft that I had them both in sight, and the medium large transport would pass behind the small aircraft X. The pilot of the medium large transport called the tower after landing to explain that his TCASII had alerted him and instructed him to 'pull up' or 'climb.' I feel that had I not stated that I had both in sight, the medium large transport would have initiated a go around, causing a 'coordination nightmare.' (or possible conflict with the small aircraft X). Anyone landing runway 30 or 12 at long beach needs to be aware that they will almost always be traffic on downwind for the crossing runways and to be extra alert and listen very closely to the controller. TCASII seems to be a good system, but at a controled airport, a RA may cause more harm than good. I know of at least one airline that requires the RA system to be turned off once the aircraft is established on final approach. I recommend that all TCASII equipped aircraft be required to turn off the RA when established on final.

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Original NASA ASRS Text

Title: MLG RECEIVED TCASII RA CLB FROM SMA X IN MULTIPLE RWY OP INTERSECTING RWYS XING TFC PATTERNS.

Narrative: AT LONG BEACH ARPT, THE L DOWNWIND FOR RWY 25L PASSES OVER THE RWY 30 FINAL APCH COURSE ABOUT 1 MI OUT. THE AIRPLANES LNDG ON RWY 30 GENERALLY PASS ABOUT 500 FT BELOW THE RWY 25L DOWNWIND TFC. I AM REQUIRED TO GIVE TA'S TO ALL ACFT CONCERNED WHEN APCHS ARE BEING MADE TO BOTH RWYS. TIMING AT THE RWY 25L-30 INTXN IS CRITICAL. THE INTXN MUST BE CLR OF ANY XING TFC BEFORE AN ACFT CAN CROSS EITHER THRESHOLD. ON THIS OCCASION, THERE WERE 2 SMA'S TURNING DOWNWIND FOR RWY 25L (L TFC) AND A TCASII EQUIPPED MLG AT 'BECCA' (LOM FOR ILS 30 LGB), ALONG WITH SEVERAL OTHER ACFT ON FREQ. HE FIRST MLG HAD BEEN CLRED TO LAND RWY 25L, WITH THE MLG FOLLOWING THROUGH THE INTXN ON RWY 30, ALSO WITH CLRNC TO LAND. THE SECOND SMA X WAS INSTRUCTED TO EXTEND DOWNWIND FOR AN MLG LNDG 30. TFC WAS GIVEN TO BOTH THE SMA X EXTENDING AND THE MLG ON FINAL DUE TO THE POOR VISIBILITY, (3 MI) THE MLG COULD NOT SEE THE SMA X THEREFORE, IT WAS MY RESPONSIBILITY TO PROVIDE THE REQUIRED VISUAL SEPARATION. THE MLG PASSED BELOW AND BEHIND THE SMA X AND LANDED, AFTER I HAD ADVISED BOTH ACFT THAT I HAD THEM BOTH IN SIGHT, AND THE MLG WOULD PASS BEHIND THE SMA X. THE PLT OF THE MLG CALLED THE TWR AFTER LNDG TO EXPLAIN THAT HIS TCASII HAD ALERTED HIM AND INSTRUCTED HIM TO 'PULL UP' OR 'CLB.' I FEEL THAT HAD I NOT STATED THAT I HAD BOTH IN SIGHT, THE MLG WOULD HAVE INITIATED A GAR, CAUSING A 'COORD NIGHTMARE.' (OR POSSIBLE CONFLICT WITH THE SMA X). ANYONE LNDG RWY 30 OR 12 AT LONG BEACH NEEDS TO BE AWARE THAT THEY WILL ALMOST ALWAYS BE TFC ON DOWNWIND FOR THE XING RWYS AND TO BE EXTRA ALERT AND LISTEN VERY CLOSELY TO THE CTLR. TCASII SEEMS TO BE A GOOD SYS, BUT AT A CTLED ARPT, A RA MAY CAUSE MORE HARM THAN GOOD. I KNOW OF AT LEAST ONE AIRLINE THAT REQUIRES THE RA SYS TO BE TURNED OFF ONCE THE ACFT IS ESTABLISHED ON FINAL APCH. I RECOMMEND THAT ALL TCASII EQUIPPED ACFT BE REQUIRED TO TURN OFF THE RA WHEN ESTABLISHED ON FINAL.

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.