C210 pilot has an altitude deviation in ZJX airspace.

Attributes
ACN	703696
Time
Date	200607
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : dts.airport
State Reference	FL
Altitude	agl bound lower : 9500 agl bound upper : 41 agl single value : 40 msl single value : 12000
Environment
Flight Conditions	IMC
Weather Elements	Thunderstorm Turbulence Rain
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zjx.artcc
Operator	general aviation : personal
Make Model Name	Cessna 120
Operating Under FAR Part	Part 91
Flight Phase	climbout : vacating altitude climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	other
Function	observation : passenger
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 10000 flight time type : 0
ASRS Report	703696
Person 2
Affiliation	other
Function	flight crew : single pilot
Events
Anomaly	inflight encounter : turbulence inflight encounter : weather non adherence : clearance non adherence : far
Independent Detector	aircraft equipment : gpws other flight crewa
Resolutory Action	flight crew : returned to assigned altitude
Supplementary
Problem Areas	Environmental Factor Flight Crew Human Performance Weather
Primary Problem	Flight Crew Human Performance

Narrative:

Flight was conducted under IMC. Takeoff uneventful. During climb encountered building thunderstorm cell and exceeded cruise altitude by 1000 ft due to strong updraft. During climb out from destin a line of small buildups were starting to form into thunderstorms. Using visual reference and a suggested heading from ZJX; PIC tried to navigation around and over buildups. As the aircraft was near gross weight and a very hot day; climb rate was down to 500 FPM passing through 9500 ft. Based on a suggested heading from ATC we entered a building cloud. From visual observation the area looked light in color with no lightning observed. Upon entering the small buildup; the aircraft entered a strong updraft exceeding approximately 3000 FPM. PIC attempted to slow climb rate by lowering nose and reducing power. Airspeed increased to the yellow arc and power was reduced further. Heavy rain and moderate turbulence were encountered. PIC asked me to look for a lighter or clear area to fly to. I suggested a slight turn based on lighting conditions. We shortly flew out the side and began an immediate descent. About this time ZJX asked our intentions since we had climbed to 12000 ft. We said we were in a descent to 11000 ft. ZJX had advised he just started picking up a strong radar return for WX in our area. Incident caused by poor assumption that center radar could give a good picture of the WX and using visual cues to fly through a building line of storms. Gross underestimate of the updraft strength and how fast it could climb the airplane.

Original NASA ASRS Text

Title: C210 PLT HAS AN ALTDEV IN ZJX AIRSPACE.

Narrative: FLT WAS CONDUCTED UNDER IMC. TKOF UNEVENTFUL. DURING CLB ENCOUNTERED BUILDING TSTM CELL AND EXCEEDED CRUISE ALT BY 1000 FT DUE TO STRONG UPDRAFT. DURING CLBOUT FROM DESTIN A LINE OF SMALL BUILDUPS WERE STARTING TO FORM INTO TSTMS. USING VISUAL REF AND A SUGGESTED HDG FROM ZJX; PIC TRIED TO NAV AROUND AND OVER BUILDUPS. AS THE ACFT WAS NEAR GROSS WT AND A VERY HOT DAY; CLB RATE WAS DOWN TO 500 FPM PASSING THROUGH 9500 FT. BASED ON A SUGGESTED HDG FROM ATC WE ENTERED A BUILDING CLOUD. FROM VISUAL OBSERVATION THE AREA LOOKED LIGHT IN COLOR WITH NO LIGHTNING OBSERVED. UPON ENTERING THE SMALL BUILDUP; THE ACFT ENTERED A STRONG UPDRAFT EXCEEDING APPROX 3000 FPM. PIC ATTEMPTED TO SLOW CLB RATE BY LOWERING NOSE AND REDUCING PWR. AIRSPD INCREASED TO THE YELLOW ARC AND PWR WAS REDUCED FURTHER. HVY RAIN AND MODERATE TURB WERE ENCOUNTERED. PIC ASKED ME TO LOOK FOR A LIGHTER OR CLEAR AREA TO FLY TO. I SUGGESTED A SLIGHT TURN BASED ON LIGHTING CONDITIONS. WE SHORTLY FLEW OUT THE SIDE AND BEGAN AN IMMEDIATE DSCNT. ABOUT THIS TIME ZJX ASKED OUR INTENTIONS SINCE WE HAD CLBED TO 12000 FT. WE SAID WE WERE IN A DSCNT TO 11000 FT. ZJX HAD ADVISED HE JUST STARTED PICKING UP A STRONG RADAR RETURN FOR WX IN OUR AREA. INCIDENT CAUSED BY POOR ASSUMPTION THAT CTR RADAR COULD GIVE A GOOD PICTURE OF THE WX AND USING VISUAL CUES TO FLY THROUGH A BUILDING LINE OF STORMS. GROSS UNDERESTIMATE OF THE UPDRAFT STRENGTH AND HOW FAST IT COULD CLB THE AIRPLANE.

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.