Narrative:

On departure from phl we were cleared to 11000 ft, direct mxe. ZNY said we had traffic ahead, non-confirmed 1000 ft above, 10 mi, appears to be descending. We received a second call that the 12 O'clock traffic was 11500 and appeared to be descending. I told copilot to obtain a turn away from traffic and I disconnected the autoplt. We were advised to turn left to 240 degree heading from 300 degrees. As I expedited a left turn, the first officer and so said they saw traffic at 1 O'clock. TCASII then showed traffic off nose plus 400 ft descending and gave us an RA with 'descend.' I pushed over and descended toward green arc at the bottom of the vsi. I finally saw traffic at 12 O'clock and we passed directly under a single engine light aircraft heading the same direction we were. TCASII sounded 'clear of conflict' and we then obtained clearance to climb to FL230 direct EMI. We passed directly under the traffic at less then 400 ft. Our evasive descent went from 11000 to approximately 10400. My impressions: first, I'm thankful to the lord that TCASII is an 'onboard' piece of equipment that we as pilots can use for immediate help. I'm thankful it wasn't ground based. The ground based help we got turned us directly into the unseen traffic. The first officer and so are convinced there were 2 aircraft, and that the turn cleared us from a more distant conflict on our right directly with a second aircraft that I saw while following TCASII instruction. Additionally, I'm thankful that I disconnected the autoplt and could have improved our situation if I'd have reduced power and somewhat slowed the aircraft and reduced wind noise in the large transport. The noise of controller/TCASII/ talk between the crew plus wind noise made the few tense moments very noisy--sort of clutter the mind.

Google
 

Original NASA ASRS Text

Title: AN ACR LTT DSNDED IN RESPONSE TO A TCASII COMMAND TO AVOID AN SMA.

Narrative: ON DEP FROM PHL WE WERE CLRED TO 11000 FT, DIRECT MXE. ZNY SAID WE HAD TFC AHEAD, NON-CONFIRMED 1000 FT ABOVE, 10 MI, APPEARS TO BE DSNDING. WE RECEIVED A SECOND CALL THAT THE 12 O'CLOCK TFC WAS 11500 AND APPEARED TO BE DSNDING. I TOLD COPLT TO OBTAIN A TURN AWAY FROM TFC AND I DISCONNECTED THE AUTOPLT. WE WERE ADVISED TO TURN L TO 240 DEG HDG FROM 300 DEGS. AS I EXPEDITED A L TURN, THE FO AND SO SAID THEY SAW TFC AT 1 O'CLOCK. TCASII THEN SHOWED TFC OFF NOSE PLUS 400 FT DSNDING AND GAVE US AN RA WITH 'DSND.' I PUSHED OVER AND DSNDED TOWARD GREEN ARC AT THE BOTTOM OF THE VSI. I FINALLY SAW TFC AT 12 O'CLOCK AND WE PASSED DIRECTLY UNDER A SINGLE ENG LIGHT ACFT HDG THE SAME DIRECTION WE WERE. TCASII SOUNDED 'CLR OF CONFLICT' AND WE THEN OBTAINED CLRNC TO CLB TO FL230 DIRECT EMI. WE PASSED DIRECTLY UNDER THE TFC AT LESS THEN 400 FT. OUR EVASIVE DSCNT WENT FROM 11000 TO APPROX 10400. MY IMPRESSIONS: FIRST, I'M THANKFUL TO THE LORD THAT TCASII IS AN 'ONBOARD' PIECE OF EQUIP THAT WE AS PLTS CAN USE FOR IMMEDIATE HELP. I'M THANKFUL IT WASN'T GND BASED. THE GND BASED HELP WE GOT TURNED US DIRECTLY INTO THE UNSEEN TFC. THE FO AND SO ARE CONVINCED THERE WERE 2 ACFT, AND THAT THE TURN CLRED US FROM A MORE DISTANT CONFLICT ON OUR R DIRECTLY WITH A SECOND ACFT THAT I SAW WHILE FOLLOWING TCASII INSTRUCTION. ADDITIONALLY, I'M THANKFUL THAT I DISCONNECTED THE AUTOPLT AND COULD HAVE IMPROVED OUR SIT IF I'D HAVE REDUCED PWR AND SOMEWHAT SLOWED THE ACFT AND REDUCED WIND NOISE IN THE LGT. THE NOISE OF CTLR/TCASII/ TALK BTWN THE CREW PLUS WIND NOISE MADE THE FEW TENSE MOMENTS VERY NOISY--SORT OF CLUTTER THE MIND.

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.