Narrative:

While level at 6000 ft 5 mi southeast of bunts intersection at 250 KTS clean, we had just been handed off to phl final approach when we got a TCASII RA to climb full scale 6000 FPM with no proximate traffic preliminaries. The first officer as PF immediately began a maximum performance climb while I went heads up to acquire the traffic which had popped up at 12 O'clock position less than 1 mi altitude -03. I did not see any traffic and by the time I could get a word in edgewise on the frequency to tell ATC about the RA, the RA had evaporated with no 'clear of conflict' annunciation. (Initially, the target had appeared to climb with us, maintaining a -00 altitude differential.) the first officer leveled off at 7000 ft and then began a descent back down to 6000 ft and ATC said there was no traffic near us which should have provided an RA. I tested the TCASII (test ok) and asked the lead flight attendant to do a ped walk, she reported no obvious ped use. As approach handed us off to local, he told us there was VFR traffic below us at 3500 ft at the time of the RA. When we got to the gate, the lead came up to say that a flight attendant had caught a lady trying to call her daughter on her cell phone at the time we 'pulled up.'

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Original NASA ASRS Text

Title: A FALSE TCASII RA SENDS A DC9 FLT INTO A CLB TO AVOID A POTENTIAL TARGET 5 MI SE OF BUNTS INTXN, PA.

Narrative: WHILE LEVEL AT 6000 FT 5 MI SE OF BUNTS INTXN AT 250 KTS CLEAN, WE HAD JUST BEEN HANDED OFF TO PHL FINAL APCH WHEN WE GOT A TCASII RA TO CLB FULL SCALE 6000 FPM WITH NO PROXIMATE TFC PRELIMINARIES. THE FO AS PF IMMEDIATELY BEGAN A MAX PERFORMANCE CLB WHILE I WENT HEADS UP TO ACQUIRE THE TFC WHICH HAD POPPED UP AT 12 O'CLOCK POS LESS THAN 1 MI ALT -03. I DID NOT SEE ANY TFC AND BY THE TIME I COULD GET A WORD IN EDGEWISE ON THE FREQ TO TELL ATC ABOUT THE RA, THE RA HAD EVAPORATED WITH NO 'CLR OF CONFLICT' ANNUNCIATION. (INITIALLY, THE TARGET HAD APPEARED TO CLB WITH US, MAINTAINING A -00 ALT DIFFERENTIAL.) THE FO LEVELED OFF AT 7000 FT AND THEN BEGAN A DSCNT BACK DOWN TO 6000 FT AND ATC SAID THERE WAS NO TFC NEAR US WHICH SHOULD HAVE PROVIDED AN RA. I TESTED THE TCASII (TEST OK) AND ASKED THE LEAD FLT ATTENDANT TO DO A PED WALK, SHE RPTED NO OBVIOUS PED USE. AS APCH HANDED US OFF TO LCL, HE TOLD US THERE WAS VFR TFC BELOW US AT 3500 FT AT THE TIME OF THE RA. WHEN WE GOT TO THE GATE, THE LEAD CAME UP TO SAY THAT A FLT ATTENDANT HAD CAUGHT A LADY TRYING TO CALL HER DAUGHTER ON HER CELL PHONE AT THE TIME WE 'PULLED UP.'

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.