Narrative:

We took off from phl on runway 9L. After takeoff departure control cleared us to 10000 ft and direct to mxe VOR. When en route to mxe we saw thunderstorms dead ahead and to the right of our flight path. Notified departure we needed a left turn to circumnav large buildup. Radar picture showed intense return (contour). Departure said unable left turn due to restr area. We then requested a climb as visually we felt we could top the largest return at about 13000 ft. Departure control was unable higher and switched us to new york center. We requested immediate climb and/or left turn to avoid the thunderstorm cell. After several calls to new york center and no response we switched back to phl departure and again requested, with urgency, a left turn. Phl said unable but gave us right turn to an east heading. At that time, to avoid flying into the cell, I turned right. We penetrated the cell and entered strong updrafts which caused us to gain approximately 500 ft. I immediately initiated corrective action and descended back to 10000 ft and exited the cell on the east heading. We then held approximately 15 mins on ptw 190/10 as instructed by phl departure until center airspace was available and continued flight to destination. Problem arose when, due to traffic, restr airspace, and thunderstorms we were unable to maneuver to avoid hazardous WX. Problem was worsened when new york center failed to give us a clearance to avoid the WX. By the time we got back to phl departure it was too late to avoid flying into the fringes of the buildup which caused the altitude deviation.

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Original NASA ASRS Text

Title: ACR WDB ALT DEV EXCURSION FROM CLRNC ALT IN TSTM ACTIVITY.

Narrative: WE TOOK OFF FROM PHL ON RWY 9L. AFTER TKOF DEP CTL CLRED US TO 10000 FT AND DIRECT TO MXE VOR. WHEN ENRTE TO MXE WE SAW TSTMS DEAD AHEAD AND TO THE R OF OUR FLT PATH. NOTIFIED DEP WE NEEDED A L TURN TO CIRCUMNAV LARGE BUILDUP. RADAR PICTURE SHOWED INTENSE RETURN (CONTOUR). DEP SAID UNABLE L TURN DUE TO RESTR AREA. WE THEN REQUESTED A CLB AS VISUALLY WE FELT WE COULD TOP THE LARGEST RETURN AT ABOUT 13000 FT. DEP CTL WAS UNABLE HIGHER AND SWITCHED US TO NEW YORK CENTER. WE REQUESTED IMMEDIATE CLB AND/OR L TURN TO AVOID THE TSTM CELL. AFTER SEVERAL CALLS TO NEW YORK CENTER AND NO RESPONSE WE SWITCHED BACK TO PHL DEP AND AGAIN REQUESTED, WITH URGENCY, A L TURN. PHL SAID UNABLE BUT GAVE US R TURN TO AN E HDG. AT THAT TIME, TO AVOID FLYING INTO THE CELL, I TURNED R. WE PENETRATED THE CELL AND ENTERED STRONG UPDRAFTS WHICH CAUSED US TO GAIN APPROX 500 FT. I IMMEDIATELY INITIATED CORRECTIVE ACTION AND DSNDED BACK TO 10000 FT AND EXITED THE CELL ON THE E HDG. WE THEN HELD APPROX 15 MINS ON PTW 190/10 AS INSTRUCTED BY PHL DEP UNTIL CENTER AIRSPACE WAS AVAILABLE AND CONTINUED FLT TO DEST. PROBLEM AROSE WHEN, DUE TO TFC, RESTR AIRSPACE, AND TSTMS WE WERE UNABLE TO MANEUVER TO AVOID HAZARDOUS WX. PROBLEM WAS WORSENED WHEN NEW YORK CENTER FAILED TO GIVE US A CLRNC TO AVOID THE WX. BY THE TIME WE GOT BACK TO PHL DEP IT WAS TOO LATE TO AVOID FLYING INTO THE FRINGES OF THE BUILDUP WHICH CAUSED THE ALT DEV.

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.