GA pilot on VFR flight gets caught in updraft and exceeds altitude restriction.

Attributes
ACN	174348
Time
Date	199103
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : oma
State Reference	NE
Altitude	msl bound lower : 4500 msl bound upper : 4800
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : oma
Operator	general aviation : instructional
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : cfi
Experience	flight time last 90 days : 250 flight time total : 1400 flight time type : 40
ASRS Report	174348
Person 2
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
Events
Anomaly	altitude deviation : overshoot inflight encounter : weather non adherence : clearance
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : exited adverse environment
Consequence	Other
Supplementary
Primary Problem	Weather
Air Traffic Incident	Pilot Deviation other

Narrative:

Altitude restriction of 4500' was exceeded by 300' because of an updraft that was going into a nearby thunderstorm. The power was back to idle and the aircraft was still climbing at 130 KTS. The altitude that was finally reached was 4800'. Shortly after I descended to 4000', oma ATC departure queried my altitude when it reached 4800' (altitude encoder). I should have told ATC that I could not hold the altitude restriction as I was going through 4500'. Next time I will report when I am unable to comply with a clearance, even if it is not my fault.

Original NASA ASRS Text

Title: GA PLT ON VFR FLT GETS CAUGHT IN UPDRAFT AND EXCEEDS ALT RESTRICTION.

Narrative: ALT RESTRICTION OF 4500' WAS EXCEEDED BY 300' BECAUSE OF AN UPDRAFT THAT WAS GOING INTO A NEARBY TSTM. THE PWR WAS BACK TO IDLE AND THE ACFT WAS STILL CLBING AT 130 KTS. THE ALT THAT WAS FINALLY REACHED WAS 4800'. SHORTLY AFTER I DSNDED TO 4000', OMA ATC DEP QUERIED MY ALT WHEN IT REACHED 4800' (ALT ENCODER). I SHOULD HAVE TOLD ATC THAT I COULD NOT HOLD THE ALT RESTRICTION AS I WAS GOING THROUGH 4500'. NEXT TIME I WILL RPT WHEN I AM UNABLE TO COMPLY WITH A CLRNC, EVEN IF IT IS NOT MY FAULT.

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.