ATC traffic vectors and an intense thunderstorm on the vector path lead to an emergency declaration ...

Attributes
ACN	755965
Time
Date	200709
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sju.airport
State Reference	PR
Altitude	msl single value : 8000
Environment
Weather Elements	Rain Thunderstorm
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sju.tracon
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	755956
Person 2
Affiliation	government : faa
Function	controller : approach
Events
Anomaly	inflight encounter : turbulence inflight encounter : weather non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency flight crew : took precautionary avoidance action
Supplementary
Problem Areas	Flight Crew Human Performance Environmental Factor ATC Human Performance Weather
Primary Problem	Environmental Factor

Narrative:

Tracking inbound to sju VOR; sju approach requested that we turn left to 270 degrees for traffic. There was a large cell on that heading; and I told ATC that we would make the turn; but could only maintain that heading for a few mins before needing a turn back to the right to avoid the cell. The thunderstorm was painting almost solid red on radar; and was quite large. I saw traffic pass by on TCAS after a few moments; and requested a right turn away from the cell. ATC denied the turn; and advised that there was yet another aircraft approaching on our right. He also advised that previous aircraft had flown through the cell with no problems. By this time; the cell was directly in front of us. I declared an emergency; advised ATC that we were making an immediate right turn away from the cell; and instructed my first officer to turn north immediately. We were unable to completely avoid penetrating the cell; and encountered moderate turbulence in the turn. Fortunately; the flight attendants had completed their landing preparations by this point; and were in their seats. I will be extremely reluctant to accept any such clearance from ATC in the future -- absolutely unacceptable!

Original NASA ASRS Text

Title: ATC TRAFFIC VECTORS AND AN INTENSE THUNDERSTORM ON THE VECTOR PATH LEAD TO AN EMERGENCY DECLARATION BY B757-200 FLT CREW TO AVOID THE CELL.

Narrative: TRACKING INBOUND TO SJU VOR; SJU APCH REQUESTED THAT WE TURN L TO 270 DEGS FOR TFC. THERE WAS A LARGE CELL ON THAT HDG; AND I TOLD ATC THAT WE WOULD MAKE THE TURN; BUT COULD ONLY MAINTAIN THAT HDG FOR A FEW MINS BEFORE NEEDING A TURN BACK TO THE R TO AVOID THE CELL. THE TSTM WAS PAINTING ALMOST SOLID RED ON RADAR; AND WAS QUITE LARGE. I SAW TFC PASS BY ON TCAS AFTER A FEW MOMENTS; AND REQUESTED A R TURN AWAY FROM THE CELL. ATC DENIED THE TURN; AND ADVISED THAT THERE WAS YET ANOTHER ACFT APCHING ON OUR R. HE ALSO ADVISED THAT PREVIOUS ACFT HAD FLOWN THROUGH THE CELL WITH NO PROBS. BY THIS TIME; THE CELL WAS DIRECTLY IN FRONT OF US. I DECLARED AN EMER; ADVISED ATC THAT WE WERE MAKING AN IMMEDIATE R TURN AWAY FROM THE CELL; AND INSTRUCTED MY FO TO TURN N IMMEDIATELY. WE WERE UNABLE TO COMPLETELY AVOID PENETRATING THE CELL; AND ENCOUNTERED MODERATE TURB IN THE TURN. FORTUNATELY; THE FLT ATTENDANTS HAD COMPLETED THEIR LNDG PREPARATIONS BY THIS POINT; AND WERE IN THEIR SEATS. I WILL BE EXTREMELY RELUCTANT TO ACCEPT ANY SUCH CLRNC FROM ATC IN THE FUTURE -- ABSOLUTELY UNACCEPTABLE!

Data retrieved from NASA's ASRS site as of January 2009 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.

ATC traffic vectors and an intense thunderstorm on the vector path lead to an emergency declaration by B757-200 flight crew to avoid the cell.