An A300 flight crew turn off the autoplt to avoid a thunderstorm cell resulting in a 600 ft deviatio...

Attributes
ACN	612527
Time
Date	200403
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : gqe.vor
State Reference	AR
Altitude	msl bound lower : 24000 msl bound upper : 24600
Environment
Flight Conditions	IMC
Weather Elements	Thunderstorm
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zme.artcc
Operator	common carrier : air carrier
Make Model Name	A300
Operating Under FAR Part	Part 121
Navigation In Use	other other vortac
Flight Phase	cruise : level cruise : enroute altitude change
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 60 flight time total : 9000 flight time type : 2800
ASRS Report	612527
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	altitude deviation : excursion from assigned altitude inflight encounter : turbulence inflight encounter : weather
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to assigned altitude flight crew : took evasive action flight crew : took precautionary avoidance action
Supplementary
Problem Areas	Flight Crew Human Performance Weather Environmental Factor
Primary Problem	Weather

Narrative:

We departed ZZZ en route to kmem. A long line of thunderstorms a couple of hundred mi long ran southwest/northeast between our position and mem. Our radar depicted a lot of attenuation so I told the first officer (PF) to continue on our present heading to parallel the WX. I informed ATC that we needed to continue on our heading for another 100-200 mi before we could turn south direct gqe as cleared. We were level at FL260. Our radar showed a break in the line of cells/WX, so direct gqe was now possible. ATC descended us to FL240 and turned us to a 190 degree heading direct gqe with a clearance to deviate as necessary for WX. We were IMC when we momentarily broke out only to see a build-up dead ahead and .25 mile. I looked down to adjust the radar tilt when I heard the autoplt chime sound as the first officer had disconnected the autoplt and went into a left bank of 45 degrees to fly clear of the cell. We penetrated the cell and experienced a strong updraft and started a climb. The altitude alert horn and the aural command of 'bank angle, bank angle' was very distracting, coupled with mod chop for the next 15 to 30 second, until the first officer leveled the wings and descended for 24600 ft to our correct altitude if FL240. In the middle of the confusion, we were given a crossing restr to cross. 10NM west of gqe at 10000 ft, which we complied with. Rest of flight uneventful.

Original NASA ASRS Text

Title: AN A300 FLT CREW TURN OFF THE AUTOPLT TO AVOID A TSTM CELL RESULTING IN A 600 FT DEV FROM ASSIGNED ALT.

Narrative: WE DEPARTED ZZZ ENRTE TO KMEM. A LONG LINE OF TSTMS A COUPLE OF HUNDRED MI LONG RAN SW/NE BTWN OUR POS AND MEM. OUR RADAR DEPICTED A LOT OF ATTENUATION SO I TOLD THE FO (PF) TO CONTINUE ON OUR PRESENT HDG TO PARALLEL THE WX. I INFORMED ATC THAT WE NEEDED TO CONTINUE ON OUR HDG FOR ANOTHER 100-200 MI BEFORE WE COULD TURN S DIRECT GQE AS CLRED. WE WERE LEVEL AT FL260. OUR RADAR SHOWED A BREAK IN THE LINE OF CELLS/WX, SO DIRECT GQE WAS NOW POSSIBLE. ATC DSNDED US TO FL240 AND TURNED US TO A 190 DEG HDG DIRECT GQE WITH A CLRNC TO DEVIATE AS NECESSARY FOR WX. WE WERE IMC WHEN WE MOMENTARILY BROKE OUT ONLY TO SEE A BUILD-UP DEAD AHEAD AND .25 MILE. I LOOKED DOWN TO ADJUST THE RADAR TILT WHEN I HEARD THE AUTOPLT CHIME SOUND AS THE FO HAD DISCONNECTED THE AUTOPLT AND WENT INTO A LEFT BANK OF 45 DEGREES TO FLY CLR OF THE CELL. WE PENETRATED THE CELL AND EXPERIENCED A STRONG UPDRAFT AND STARTED A CLB. THE ALT ALERT HORN AND THE AURAL COMMAND OF 'BANK ANGLE, BANK ANGLE' WAS VERY DISTRACTING, COUPLED WITH MOD CHOP FOR THE NEXT 15 TO 30 SEC, UNTIL THE FO LEVELED THE WINGS AND DESCENDED FOR 24600 FT TO OUR CORRECT ALT IF FL240. IN THE MIDDLE OF THE CONFUSION, WE WERE GIVEN A CROSSING RESTR TO CROSS. 10NM W OF GQE AT 10000 FT, WHICH WE COMPLIED WITH. REST OF FLT UNEVENTFUL.

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.

An A300 flight crew turn off the autoplt to avoid a thunderstorm cell resulting in a 600 ft deviation from assigned altitude.