B757 flight crew had an altitude deviation due to turbulence.

Attributes
ACN	523380
Time
Date	200109
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : iah.airport
State Reference	TX
Altitude	msl single value : 4000
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 195 flight time total : 18500 flight time type : 1000
ASRS Report	523380
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe inflight encounter : weather inflight encounter : turbulence non adherence : far non adherence : clearance other anomaly other
Resolutory Action	controller : issued advisory flight crew : took precautionary avoidance action flight crew : returned to assigned altitude
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Weather ATC Human Performance Flight Crew Human Performance
Primary Problem	Weather

Narrative:

Cleared for takeoff with a 140 degree heading, after takeoff heading of 120 degrees assigned. This heading aimed us right at a thunderstorm. The frequency was busy with other aircraft. We could not wait for permission to deviate. We deviated to the left and then told the controller what we were doing. Supervisory controller told us not to go left but go to the right. I disconnected the autoplt to quicken up the right turn. We got close to the thunderstorm. An updraft took us 300 ft higher than our assigned altitude. We corrected immediately, but the controller stated that she saw our deviation and that there was traffic near us. Flight continued to destination.

Original NASA ASRS Text

Title: B757 FLT CREW HAD AN ALTDEV DUE TO TURB.

Narrative: CLRED FOR TKOF WITH A 140 DEG HDG, AFTER TKOF HEADING OF 120 DEGS ASSIGNED. THIS HEADING AIMED US RIGHT AT A TSTM. THE FREQ WAS BUSY WITH OTHER ACFT. WE COULD NOT WAIT FOR PERMISSION TO DEVIATE. WE DEVIATED TO THE L AND THEN TOLD THE CTLR WHAT WE WERE DOING. SUPERVISORY CTLR TOLD US NOT TO GO L BUT GO TO THE R. I DISCONNECTED THE AUTOPLT TO QUICKEN UP THE R TURN. WE GOT CLOSE TO THE TSTM. AN UPDRAFT TOOK US 300 FT HIGHER THAN OUR ASSIGNED ALT. WE CORRECTED IMMEDIATELY, BUT THE CTLR STATED THAT SHE SAW OUR DEV AND THAT THERE WAS TFC NEAR US. FLT CONTINUED TO DEST.

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.