Air carrier medium large transport was cleared to descend through VFR traffic altitude with a traffi...

Attributes
ACN	147089
Time
Date	199005
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : pie airport : tpa
State Reference	FL
Altitude	msl bound lower : 11000 msl bound upper : 12000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zjx
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other descent other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : atp pilot : instrument
Experience	flight time last 90 days : 160 flight time total : 7000 flight time type : 900
ASRS Report	147089
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 6000 vertical : 1000
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

We were inbound to ktpa proceeding to the pie VOR. Jax center cleared us to cross 35N of pie at 13000', 250 KTS. About the same time center reported VFR traffic 12 O'clock at 11500'. Center said if we wished to turn right 15 degree to avoid the traffic we could. We did not initially turn as our level off altitude was well above the VFR traffic. As we approached 13000' and leveled off approximately 50 north of pie the controller asked had we received clearance to 11000' 35 north of pid. We replied no. 3 people in the cockpit including an ATC FSS specialist on the jump seat, did not hear any clearance to 11000'. Center said continue descent to 11000'. We began descending to 11000'. Descending through 12000', we remembered the VFR traffic. We asked the controller the traffic's position and he said 12 O'clock 1 mi. We immediately leveled off and climbed to 12000' as the controller said we could maintain 12000' if we wished. After level off center reported the traffic 8 O'clock 1 mi. None of us ever saw the traffic. After reviewing the above, it seems that though the center is not required to provide sep for us from VFR traffic, had they required us to turn we could have avoided this situation. No updates were given on the position of traffic after the initial report. I realize it is our responsibility to avoid VFR traffic and in the future I plan to immediately accept any recommended vectors to avoid VFR traffic. The controller did not at anytime seemed concerned about this situation.

Original NASA ASRS Text

Title: ACR MLG WAS CLEARED TO DESCEND THROUGH VFR TRAFFIC ALT WITH A TRAFFIC ADVISORY. FLT CREW ELECTED TO STOP THE DESCENT ABOVE THE TRAFFIC ALT UNTIL THEY WERE CLEAR OF TRAFFIC.

Narrative: WE WERE INBND TO KTPA PROCEEDING TO THE PIE VOR. JAX CTR CLRED US TO CROSS 35N OF PIE AT 13000', 250 KTS. ABOUT THE SAME TIME CTR RPTED VFR TFC 12 O'CLOCK AT 11500'. CTR SAID IF WE WISHED TO TURN R 15 DEG TO AVOID THE TFC WE COULD. WE DID NOT INITIALLY TURN AS OUR LEVEL OFF ALT WAS WELL ABOVE THE VFR TFC. AS WE APCHED 13000' AND LEVELED OFF APPROX 50 N OF PIE THE CTLR ASKED HAD WE RECEIVED CLRNC TO 11000' 35 N OF PID. WE REPLIED NO. 3 PEOPLE IN THE COCKPIT INCLUDING AN ATC FSS SPECIALIST ON THE JUMP SEAT, DID NOT HEAR ANY CLRNC TO 11000'. CTR SAID CONTINUE DSNT TO 11000'. WE BEGAN DSNDING TO 11000'. DSNDING THROUGH 12000', WE REMEMBERED THE VFR TFC. WE ASKED THE CTLR THE TFC'S POS AND HE SAID 12 O'CLOCK 1 MI. WE IMMEDIATELY LEVELED OFF AND CLBED TO 12000' AS THE CTLR SAID WE COULD MAINTAIN 12000' IF WE WISHED. AFTER LEVEL OFF CTR RPTED THE TFC 8 O'CLOCK 1 MI. NONE OF US EVER SAW THE TFC. AFTER REVIEWING THE ABOVE, IT SEEMS THAT THOUGH THE CTR IS NOT REQUIRED TO PROVIDE SEP FOR US FROM VFR TFC, HAD THEY REQUIRED US TO TURN WE COULD HAVE AVOIDED THIS SITUATION. NO UPDATES WERE GIVEN ON THE POS OF TFC AFTER THE INITIAL RPT. I REALIZE IT IS OUR RESPONSIBILITY TO AVOID VFR TFC AND IN THE FUTURE I PLAN TO IMMEDIATELY ACCEPT ANY RECOMMENDED VECTORS TO AVOID VFR TFC. THE CTLR DID NOT AT ANYTIME SEEMED CONCERNED ABOUT THIS SITUATION.

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.

Air carrier medium large transport was cleared to descend through VFR traffic altitude with a traffic advisory. Flight crew elected to stop the descent above the traffic altitude until they were clear of traffic.