Air carrier X TCASII TA RA with VFR aircraft evasive action descent climb. See and avoid concept.

Attributes
ACN	290140
Time
Date	199411
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ard
State Reference	PA
Altitude	msl bound lower : 8500 msl bound upper : 9000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : phl
Operator	common carrier : air carrier
Make Model Name	DC-9 30
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 8000 flight time type : 3000
ASRS Report	290190
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : undershoot conflict : airborne less severe non adherence : clearance
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 12000 vertical : 100
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

Air carrier X level 9000 ft heading east, given 6000 ft and a right turn to 160 degrees. Before we could acknowledge clearance, another aircraft read back our clearance. During this time TCASII called out 'traffic, traffic.' we observed target at 11:30 position on TCASII 3 NM and 300 ft below. TCASII then said 'descend, descend' followed immediately by climb, climb and the green dots on the vsi were at 2000 FPM climb. Captain started a climbing right turn. I told approach we were responding to a TCASII command and were climbing. I also was trying to find the target visually. Unfortunately, there were broken clouds in the area where the traffic should be. At 9400 ft TCASII said 'monitor vertical speed' which said level. I told approach we were leveling at 9500 ft and also had time now to tell him someone else had accepted our clearance. After he got that straightened out we were now ready to comply with the original clearance. Frequency congestion at this time prevented us from getting all the information about the TCASII traffic. After landing in phl I called approach control and they said they had a VFR traffic above the TCA at 8500 ft wbound and when the controller went to call out the VFR traffic the frequency congestion started. He didn't see him climb. TCASII worked as advertised. We chose 9500 ft to prevent traffic conflict, which I was told by approach there was no traffic conflict.

Original NASA ASRS Text

Title: ACR X TCASII TA RA WITH VFR ACFT EVASIVE ACTION DSCNT CLB. SEE AND AVOID CONCEPT.

Narrative: ACR X LEVEL 9000 FT HDG E, GIVEN 6000 FT AND A R TURN TO 160 DEGS. BEFORE WE COULD ACKNOWLEDGE CLRNC, ANOTHER ACFT READ BACK OUR CLRNC. DURING THIS TIME TCASII CALLED OUT 'TFC, TFC.' WE OBSERVED TARGET AT 11:30 POS ON TCASII 3 NM AND 300 FT BELOW. TCASII THEN SAID 'DSND, DSND' FOLLOWED IMMEDIATELY BY CLB, CLB AND THE GREEN DOTS ON THE VSI WERE AT 2000 FPM CLB. CAPT STARTED A CLBING R TURN. I TOLD APCH WE WERE RESPONDING TO A TCASII COMMAND AND WERE CLBING. I ALSO WAS TRYING TO FIND THE TARGET VISUALLY. UNFORTUNATELY, THERE WERE BROKEN CLOUDS IN THE AREA WHERE THE TFC SHOULD BE. AT 9400 FT TCASII SAID 'MONITOR VERT SPD' WHICH SAID LEVEL. I TOLD APCH WE WERE LEVELING AT 9500 FT AND ALSO HAD TIME NOW TO TELL HIM SOMEONE ELSE HAD ACCEPTED OUR CLRNC. AFTER HE GOT THAT STRAIGHTENED OUT WE WERE NOW READY TO COMPLY WITH THE ORIGINAL CLRNC. FREQ CONGESTION AT THIS TIME PREVENTED US FROM GETTING ALL THE INFO ABOUT THE TCASII TFC. AFTER LNDG IN PHL I CALLED APCH CTL AND THEY SAID THEY HAD A VFR TFC ABOVE THE TCA AT 8500 FT WBOUND AND WHEN THE CTLR WENT TO CALL OUT THE VFR TFC THE FREQ CONGESTION STARTED. HE DIDN'T SEE HIM CLB. TCASII WORKED AS ADVERTISED. WE CHOSE 9500 FT TO PREVENT TFC CONFLICT, WHICH I WAS TOLD BY APCH THERE WAS NO TFC CONFLICT.

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.